Toyota Avalon (XX50): Pre-collision System(for Gasoline Model)

Front Radar Sensor Region Code Mismatch (C1A0A)

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle.

Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly calculates the possibility of a collision and operates the pre-collision system if it determines that the possibility is high.

When the millimeter wave radar sensor assembly is replaced with a new one, it acquires the country specification information from the driving support ECU assembly. Also, when the driving support ECU assembly is replaced with a new one, it receives country specification information from the main body ECU (multiplex network body ECU). If country specification information in the millimeter wave radar sensor assembly, driving support ECU and/or main body ECU do not match, DTC C1A0A will be stored.

CAUTION / NOTICE / HINT

NOTICE:

• When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

• The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

  Click here

PROCEDURE

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

USE SIMULATION METHOD TO CHECK

B

(a) Replace the driving support ECU assembly.

Click here

NEXT

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE)

B

(a) Replace the millimeter wave radar sensor assembly.

Click here

(b) Adjust the millimeter wave radar sensor assembly.

Click here

NEXT

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

Driving Support ECU (C1A01)

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle.

Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly calculates the possibility of a collision and operates the pre-collision system if it determines that the possibility is high.

CAUTION / NOTICE / HINT

NOTICE:

When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.

PROCEDURE

(a) Replace the driving support ECU assembly.

Click here

NEXT

END

Vehicle Information Not Obtained (C1A02)

DESCRIPTION

When a new driving support ECU assembly is installed, it receives vehicle specification information (destination, steering wheel position, etc.) from the main body ECU (multiplex network body ECU) and stores the information.

DTC C1A02 is stored when the driving support ECU assembly receives the vehicle specification information from the main body ECU (multiplex network body ECU) but cannot store it.

CAUTION / NOTICE / HINT

NOTICE:

• When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

  Click here

PROCEDURE

(a) Replace the driving support ECU assembly.

Click here

NEXT

END

Stop Light Relay Circuit (C1A4B)

DESCRIPTION

The skid control ECU (brake actuator assembly) sends a stop light operation request signal to the stop light relay (stop light switch assembly). If the skid control ECU (brake actuator assembly) detects a malfunction in the stop light relay (stop light switch assembly) circuit, the driving support ECU assembly stores DTC C1A4B.

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

HINT:

If DTC C1A4B is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END

Front Radar Sensor (C1A10)

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle.

Based on this signals from the millimeter wave radar sensor assembly, the driving support ECU assembly sends pre-collision system control operation signals.

If the driving support ECU assembly receives an internal malfunction signal from the millimeter wave radar sensor assembly, it stores DTC C1A10.

CAUTION / NOTICE / HINT

NOTICE:

• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

• The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

  Click here

PROCEDURE

(a) Replace the millimeter wave radar sensor assembly.

Click here

(b) Adjust the millimeter wave radar sensor assembly.

Click here

NEXT

END

Front Radar Sensor Incorrect Axial Gap (C1A11,C1A14)

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle.

Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly sends pre-collision system control operation signals.

When the vehicle is determined to be driving in a straight line or on a gradual curve based on signals from the yaw rate sensor, etc., the millimeter wave radar sensor assembly performs self diagnosis to check if the sensor beam axis has deviated. If the millimeter wave radar sensor assembly beam axis has deviated, the driving support ECU assembly detects this and stores DTC C1A11.

After installing a new millimeter wave radar sensor assembly, if sensor beam axis adjustment has not been performed, DTC C1A14 will be stored.

CAUTION / NOTICE / HINT

NOTICE:

• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

PROCEDURE

(a) Perform millimeter wave radar sensor assembly adjustment.

Click here

NEXT

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

END

B

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Yaw Rate Sensor (C1A46)

DESCRIPTION

The driving support ECU assembly receives yaw rate sensor signals from the airbag ECU assembly and skid control ECU (brake actuator assembly) via CAN communication. If the driving support ECU assembly receives a yaw rate sensor malfunction signal from the airbag ECU assembly or skid control ECU (brake actuator assembly), DTC C1A46 will be stored.

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

HINT:

If DTC C1A46 is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END

Steering Angle Sensor (C1A47)

DESCRIPTION

The driving support ECU assembly receives steering angle information from the steering sensor. If the driving support ECU assembly detects a steering sensor malfunction, DTC C1A47 will be stored.

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

HINT:

If DTC C1A47 is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END

Brake System Malfunction (C1A50)

DESCRIPTION

When the pre-collision system is operating, the driving support ECU assembly sends brake control signals to the skid control ECU (brake actuator assembly).

If the driving support ECU assembly receives an electronically controlled brake system malfunction signal from the skid control ECU (brake actuator assembly) via CAN communication, DTC C1A50 will be stored.

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

HINT:

If DTC C1A50 is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END

Other System Malfunction (C1A63)

DESCRIPTION

The driving support ECU assembly receives accelerator pedal position sensor signals from the ECM to determine if the accelerator pedal is being depressed. If the ECM detects a malfunction in the accelerator pedal position sensor or SFI system, the driving support ECU assembly is notified via CAN communication and stores DTC C1A63.

PROCEDURE

HINT:

If DTC C1A63 is output by the pre-collision system, perform troubleshooting for the SFI system.

Click here

NEXT

END

Brake Control Signal Mismatch (C1A64)

DESCRIPTION

The skid control ECU (brake actuator assembly) sends signals to the driving support ECU assembly according to the brake control status. If the driving support ECU assembly receives an electronically controlled brake system malfunction signal from the skid control ECU (brake actuator assembly), it will store DTC C1A64.

CAUTION / NOTICE / HINT

NOTICE:

The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

HINT:

If DTC C1A64 is output by the pre-collision system, perform troubleshooting for the electronically controlled brake system.

Click here

NEXT

END

Front Camera Module Circuit (C1AA0)

DESCRIPTION

The driving support ECU assembly receives information about the area in front of the vehicle from the forward recognition camera.

If the driving support ECU assembly detects a malfunction in the forward recognition camera, it will store DTC C1AA0.

CAUTION / NOTICE / HINT

NOTICE:

• When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.
• If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition camera adjustment.

  Click here

• The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

  Click here

PROCEDURE

(a) Replace the forward recognition camera.

Click here

(b) Perform forward recognition camera adjustment.

Click here

NEXT

END

Front Camera Module Beam Axis Not Adjusted (C1AA9)

DESCRIPTION

If forward recognition camera adjustment has not been performed or did not complete normally after the forward recognition camera was replaced with a new one, DTC C1AA9 will be stored.

PROCEDURE

HINT:

If DTC C1AA9 is output by the pre-collision system, perform troubleshooting for the front camera system.

Click here

NEXT

END

Heater Circuit (C1AAE)

DESCRIPTION

If the forward recognition camera detects a malfunction in the forward recognition with heater hood sub-assembly circuit, it will output a malfunction signal to the driving support ECU assembly via CAN communication and this DTC will be stored.

PROCEDURE

HINT:

If DTC C1AAE is output by the pre-collision system, perform troubleshooting for the front camera system.

Click here

NEXT

END

Customize Parameters

CUSTOMIZE PARAMETERS

NOTICE:

• When the customer requests a change in a function, first make sure that the function can be customized.
• Make a note of the current settings before customizing.

HINT:

The following PCS functions and the pre-collision system sensitivity setting can be changed from their default setting.

CUSTOMIZE PRE-COLLISION SYSTEM

(a) Customizing with the Techstream

(1) Turn the engine switch off.

(2) Connect the Techstream to the DLC3.

(3) Turn the engine switch on (IG).

(4) Turn the Techstream on.

(5) Enter the following menus: Customize Setting / Others.

(6) Select the setting by referring to the table below.

Data List / Active Test

DATA LIST / ACTIVE TEST

DATA LIST

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Pre-Collision 2 / Data List.

(e) Read the Data List according to the display on the Techstream.

ACTIVE TEST

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Pre-Collision 2 / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Diagnosis System

DIAGNOSIS SYSTEM

CHECK DLC3

(a) Check the DLC3.

Click here

FUNCTION OF WARNING INDICATOR AND MESSAGE

(a) If the pre-collision system is not functioning properly, the driver is warned by the PCS warning light and a warning message displayed on the multi-information display.

INITIAL CHECK

(a) An initial check is performed when the engine switch is off for more than 2 seconds and then turned on (IG). The initial check consists of a pre-collision system diagnostic check with a duration of approximately 3 seconds.

(b) If a malfunction is detected during the initial check, the PCS warning light in the combination meter assembly will illuminate and a warning message indicating the pre-collision system is malfunctioning or disabled will be displayed on the multi-information display.

CONSTANT CHECK

(a) The driving support ECU assembly constantly monitors the pre-collision system for malfunctions after the engine switch is turned on (IG) and the initial check (approximately 3 seconds) has completed.

(b) If a malfunction is detected during the constant check, the PCS warning light in the combination meter assembly will illuminate and a warning message indicating the pre-collision system is malfunctioning or disabled will be displayed on the multi-information display.

Diagnostic Trouble Code Chart

DIAGNOSTIC TROUBLE CODE CHART

Dtc Check / Clear

DTC CHECK / CLEAR

CHECK DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes.

(e) Check for DTCs.

Click here

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Pre-Collision 2 / Clear DTCs.

(e) Clear the DTCs.

Fail-safe Chart

FAIL-SAFE CHART

FAIL-SAFE FUNCTION

(a) When a malfunction occurs in the pre-collision system, a message will be displayed on the multi-information display and the pre-collision system will be disabled depending on the malfunction.

Freeze Frame Data

FREEZE FRAME DATA

DESCRIPTION

(a) When a pre-collision system DTC is stored, the driving support ECU assembly stores the current vehicle (ECU or sensor) state as Freeze Frame Data.

CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes.

(e) According to the Techstream display, select a DTC that stored freeze frame data.

(f) Read the freeze frame data recorded when the DTC was stored.

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

• Use these procedures to troubleshoot the pre-collision system.
• *: Use the Techstream.

PROCEDURE

NEXT

(a) Measure the battery voltage.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, replace or recharge the battery before proceeding to the next step.

NEXT

(a) Adjust the reflector height.

Click here

(b) Place the reflector.

Click here

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Turn the cruise control main switch on.

(g) Enter the following menus: Body Electrical / Pre-Collision 2 / Utility / Front Beam Axis Misalignment Reading.

(h) Check the amount of misalignment and make a note.

(i) Enter the following menus: Body Electrical / Pre-Collision 2 / Utility / Front Beam Axis Offset Reading.

(j) Check the amount of misalignment and make a note.

(k) Calculate the "Dealership Axis Offset Angle (with On-line Calibration Angle)" using the values "Front Beam Axis Misalignment Reading" and "Front Beam Axis Offset Reading".

(1) "Dealership Axis Offset Angle (with On-line Calibration Angle)" = "Front Beam Axis Misalignment Reading" - "Front Beam Axis Offset Reading"

Standard:

Dealership Axis Offset Angle (with On-line Calibration Angle)

B

GO TO STEP 12

A

(a) Using the Techstream, check if the CAN communication system is functioning normally.

HINT:

Refer to CAN Bus Check in CAN Communication System.

Click here

OK:

CAN communication system is functioning normally.

NG

GO TO CAN COMMUNICATION SYSTEM

OK

(a) Check the condition of the warning lights on the combination meter assembly.

B

GO TO MALFUNCTIONING SYSTEM

A

(a) Check if a pre-collision system warning message is displayed on the multi-information display in the combination meter assembly.

B

GO TO PROBLEM SYMPTOMS TABLE

C

CHECK CONDITIONS WHEN PRE-COLLISION SYSTEM DID NOT OPERATE

A

HINT:

Refer to DTC Check / Clear.

Click here

(a) Check for DTCs and note any codes that are output.

(b) Clear the DTCs.

(c) Recheck for DTCs.

(1) Attempt to duplicate the malfunction and check if the DTCs are output again.

B

GO TO SYMPTOM SIMULATION

C

GO TO DTC CHART

A

HINT:

Refer to Problem Symptoms Table.

Click here

B

GO TO STEP 11

A

(a) Terminals of ECU

Click here

(b) Data List / Active Test

Click here

NEXT

NOTICE:

When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

Click here

NEXT

NEXT

END

(a) Perform millimeter wave radar sensor assembly adjustment.

Click here

NEXT

GO TO STEP 4

Initialization

INITIALIZATION

STEERING SENSOR ZERO POINT CALIBRATION

(a) Start the engine.

(b) Drive the vehicle straight ahead at 35 km/h (22 mph) or more for 5 seconds or more.

(c) Turn the engine switch off.

Operation Check

OPERATION CHECK

CHECK PRE-COLLISION SYSTEM SETTING

(a) Turn the engine switch on (IG).

(b) Operate the steering pad switch assembly to change the setting of PCS on the multi-information display to "On" and check that the pre-collision system turns on.

HINT:

When the engine switch is turned on (IG), the PCS will turn on. This can be changed through a customize setting using the Techstream.

(c) Operate the steering pad switch assembly to change the PCS setting to "Off" and check that the PCS warning light illuminates.

CHECK PRE-COLLISION SYSTEM SENSITIVITY SETTING

(a) Turn the engine switch on (IG).

(b) Operate the steering pad switch assembly to select Change PCS Sensitivity and check that the warning timing adjustment display on the multi-information display changes between "Far", "Mid" and "Near" accordingly.

HINT:

• The pre-collision system warning timing status remains unchanged when the engine switch is turned off and back to ON. This can be changed through a customize setting using the Techstream.
• The default setting is "Mid".

Parts Location

PARTS LOCATION

ILLUSTRATION

ILLUSTRATION

ILLUSTRATION

Precaution

PRECAUTION

HANDLING PRECAUTION FOR PRE-COLLISION SYSTEM

(a) In some situations such as the following, the system may determine that there is a possibility of a frontal collision and operate.

• When passing a vehicle or pedestrian
• When changing lanes while overtaking a preceding vehicle
• When overtaking a preceding vehicle that is changing lanes
• When overtaking a preceding vehicle that is making a left/right turn
• When passing a vehicle in an oncoming lane that is stopped to make a right/left turn
• When driving on a road where relative location to vehicle ahead in an adjacent lane may change, such as on a winding road
• When rapidly closing on a vehicle ahead
• If the front of the vehicle is raised or lowered, such as when the road surface is uneven or undulating
• When approaching objects on the roadside, such as guardrails, utility poles, trees, or walls
• When there is a vehicle, pedestrian, or object by the roadside at the entrance of a curve
• When driving on a narrow path surrounded by a structure, such as in a tunnel or on an iron bridge
• When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion on the road surface or roadside
• When a crossing pedestrian approaches very close to the vehicle
• When passing through a place with a low structure above the road (low ceiling, traffic sign, etc.)
• When passing under an object (billboard, etc.) at the top of an uphill road
• When rapidly closing on an electric toll gate barrier, parking area barrier, or other barrier that opens and closes
• When using an automatic car wash
• When driving through or under objects that may contact the vehicle, such as thick grass, tree branches, or a banner
• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When there are patterns or paint on the road or a wall that may be mistaken for a vehicle or pedestrian
• When driving near an object that reflects radio waves, such as a large truck or guardrail
• When driving near a TV tower, broadcasting station, electric power plant, or other location where strong radio waves or electrical noise may be present

(b) In some situations such as the following, a vehicle may not be detected by the millimeter wave radar sensor assembly and forward recognition camera, preventing the system from operating properly.

• If an oncoming vehicle is approaching your vehicle
• If a vehicle ahead is a motorcycle or bicycle
• When approaching the side or front of a vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a preceding vehicle has a low rear end, such as a low bed trailer
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead has extremely high ground clearance
• If a vehicle ahead is irregularly shaped, such as a tractor or side car
• If the sun or other light is shining directly on a vehicle ahead
• If a vehicle cuts in front of your vehicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, acceleration or deceleration)
• When suddenly cutting behind a preceding vehicle
• When a vehicle ahead is not directly in front of your vehicle
• When driving in inclement weather such as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of oncoming traffic, shines directly into the forward recognition camera
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel
• After the engine has started the vehicle has not been driven for a certain amount of time
• While making a left/right turn and for a few seconds after making a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or lowered
• If the wheels are misaligned
• If a wiper blade is blocking the forward recognition camera
• The vehicle is wobbling
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the millimeter wave radar sensor assembly or forward recognition camera is misaligned

(c) In some situations such as the following, sufficient braking force may not be obtained, preventing the system from performing properly.

• If the braking functions cannot operate to their full extent, such as when the brake parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively worn, improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery surface

(d) Some pedestrians such as the following may not be detected by the millimeter wave radar sensor assembly and forward recognition camera, preventing the system from operating properly.

• Pedestrians shorter than approximately 1 m (3.2 ft.) or taller than approximately 2 m (6.5 ft.)
• Pedestrians wearing oversized clothing (a rain coat, long skirt, etc.), making their silhouette obscure
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller, wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as their surroundings
• Pedestrians near walls, fences, guardrails, or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from behind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view mirror, etc.)

(e) When the PCS warning light illuminates and a warning message is displayed on the multi-information display, the system may not temporarily operate, or it may have a malfunction.

HINT:

For details on the operation of the PCS warning light and displayed warning messages, refer to Diagnosis System.

Click here

(1) In the following situations, the warning light will turn off, the message will disappear and the system will become operational when normal operating conditions return.

• When the millimeter wave radar sensor assembly or forward recognition camera or the area around either sensor is hot, such as in the sun
• When the millimeter wave radar sensor assembly or forward recognition camera or the area around either sensor is cold, such as in an extremely cold environment
• When a millimeter wave radar sensor assembly or forward recognition camera is dirty or covered with snow, etc.
• When the part of the windshield glass in front of the forward recognition camera is fogged up or covered with condensation or ice
• If the forward recognition camera is obstructed, such as when the hood is open or a sticker is attached to the windshield glass near the forward recognition camera
• When automatic calibration is being performed after millimeter wave axis misalignment is detected

(f) If VSC is disabled, the pre-collision brake assist and pre-collision braking functions are also disabled.

HINT:

The PCS warning light will turn on and "VSC Turned Off Pre-collision Brake System Unavailable" will be displayed on the multi-information display.

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL

NOTICE:

• When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected.

  System Name	See Procedure
  Lane Departure Alert System (w/ Steering Control)
  Pre-collision System
  Intelligent Clearance Sonar System
  Lighting System (w/ Cornering Light)
  Parking Assist Monitor System
  Panoramic View Monitor System

• If the battery has been discharged and charged or the cable has been disconnected and reconnected to the negative (-) battery terminal, perform Steering Sensor Zero Point Calibration.

  Click here

PRECAUTION BEFORE SERVICING

(a) Make sure to turn the pre-collision system off in the following situations, as it may operate unexpectedly or may not operate when necessary.

• When the vehicle is being towed
• When the vehicle is towing another vehicle
• When transporting the vehicle via truck, boat, train or similar means of transportation
• When the vehicle is raised on a lift with the engine running and the tires are allowed to rotate freely
• When inspecting the vehicle using a drum tester such as a chassis dynamometer or speedometer tester, or when using an on vehicle wheel balancer
• When a strong impact is applied to the front bumper or front grille, due to an accident or other reasons
• If the vehicle cannot be driven in a stable manner, such as when the vehicle has been in an accident or is malfunctioning
• When the vehicle is driven in a sporty manner or off-road
• When the tires are not properly inflated
• When the tires are very worn
• When tires of a size other than specified are installed
• When tire chains are installed
• When a compact spare tire or an emergency tire puncture repair kit is used
• If equipment (snow plow, etc.) that may obstruct the millimeter wave radar sensor assembly or forward recognition camera is temporarily installed to the vehicle

TROUBLESHOOTING PRECAUTIONS

(a) If a terminal contact malfunction or part installation problem occurs, removal and reinstallation of the suspected part may return the system to normal. However, be aware that the normal condition may only be temporary.

(b) Before disconnecting connectors or removing/installing parts, determine the malfunctioning area by checking and writing down the vehicle conditions (output DTCs, etc.) at the time the malfunction occurred.

(c) Be sure to check for DTCs related to other systems. The pre-collision system may be influenced by malfunctions in other systems.

(d) The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

HANDLING PRECAUTIONS

(a) When removing and installing ECUs, sensors, switches or other pre-collision system related parts, perform the following:

• Make sure that the engine switch is off unless otherwise specified in the procedure.
• After removal/installation, check for DTCs and confirm that a normal system code is output.

REPLACEMENT PRECAUTIONS

(a) DRIVING SUPPORT ECU ASSEMBLY:

(1) When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

(b) MILLIMETER WAVE RADAR SENSOR ASSEMBLY:

(1) When replacing the millimeter wave radar sensor assembly, always replace it with a new one. When a new millimeter wave radar sensor assembly is installed to the vehicle, it receives vehicle information from the driving support ECU assembly and stores it. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly and millimeter wave radar sensor assembly will not match and a DTC may be stored.

(2) If the millimeter wave radar sensor assembly has been replaced with a new one, be sure to perform Front Beam Axis Adjustment.

Click here

(c) FORWARD RECOGNITION CAMERA:

(1) If the forward recognition camera has been replaced with a new one or the windshield glass has been removed and installed, it is necessary to perform forward recognition camera adjustment. If the system is turned on without performing forward recognition camera adjustment, DTC C1AA9 will be stored.

Click here

(d) WINDSHIELD GLASS:

(1) When replacing the windshield glass of a vehicle equipped with a forward recognition camera, make sure to use a Toyota genuine part. If a non-Toyota genuine part is used, the forward recognition camera may not be able to be installed due to a missing bracket or the pre-collision system may not operate properly due to a difference in the transmissivity or black ceramic border.

(2) Do not attach stickers, including transparent stickers, or other items to the outer side of the windshield glass assembly within the area in front of the forward recognition camera.

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

• Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
• Inspect the fuses and relays related to this system before inspecting the suspected areas below.
• The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

• *: If "Pre-Collision System Unavailable" is displayed on the multi-information display and there is front beam axis misalignment (vertical) history, the millimeter wave radar sensor assembly may be performing beam axis alignment correction. In this case, the message will disappear when the millimeter wave radar sensor assembly front beam axis adjustment has completed.

  "Pre-Collision System Unavailable" disappears when the millimeter wave radar sensor assembly beam axis alignment correction has completed.

  Make sure to delete the beam axis misalignment history when the millimeter wave radar sensor assembly beam axis alignment correction has completed.

  Click here

System Diagram

SYSTEM DIAGRAM

Terminals Of Ecu

TERMINALS OF ECU

CHECK DRIVING SUPPORT ECU ASSEMBLY

(a) Measure the voltage and resistance according to the value(s) in the table below.

(b) Check for pulses according to the value(s) in the table below.

HINT:

If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the driving support ECU assembly is suspected.

(1) WAVEFORM 1

HINT:

The waveform varies depending on the CAN communication signal.

(2) WAVEFORM 2

HINT:

The waveform varies depending on the CAN communication signal.

CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY

(a) Measure the voltage and resistance according to the value(s) in the table below.

(b) Check for pulses according to the value(s) in the table below.

HINT:

If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the millimeter wave radar sensor assembly is suspected.

(1) WAVEFORM 1

HINT:

The waveform varies depending on the CAN communication signal.

(2) WAVEFORM 2

HINT:

The waveform varies depending on the CAN communication signal.

Lost Communication with Front Camera Module (U023A)

DESCRIPTION

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Inspect the fuses for circuits related to this system before performing the following procedure.
• Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
• After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

  Click here

• When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.
• If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition camera adjustment.

  Click here

HINT:

• Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
• Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the connectors of ECUs or wire harnesses while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: System Select / Can Bus Check.

Click here

B

GO TO CAN COMMUNICATION SYSTEM

A

(a) Check for DTCs.

B

GO TO DTC CHART (U1002)

A

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the O5 forward recognition camera connector.

*a Front view of wire harness connector (to Forward Recognition Camera)

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(d) Connect the O5 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129,U0155)

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle. Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly sends pre-collision system control operation signals. These DTCs are stored when a communication malfunction occurs between ECUs that perform pre-collision system control.

PROCEDURE

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

USE SIMULATION METHOD TO CHECK

B

GO TO CAN COMMUNICATION SYSTEM

Lost Communication with Cruise Control Front Distance Range Sensor (U0235)

DESCRIPTION

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Inspect the fuses for circuits related to this system before performing the following procedure.
• Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
• After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

  Click here

• When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

HINT:

• Operating the engine switch, any other switches or a door triggers related ECUs and sensors to communicate using the CAN communication system. This communication will cause the resistance value to change.
• Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the connectors of ECUs or wire harnesses while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: System Select / Can Bus Check.

Click here

B

GO TO CAN COMMUNICATION SYSTEM

A

(a) Check for DTCs.

B

GO TO DTC CHART (U1002)

A

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the A25 millimeter wave radar sensor assembly connector.

*a Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(d) Connect the A25 millimeter wave radar sensor assembly connector.

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

OK

(a) Check for DTCs.

A

REPLACE DRIVING SUPPORT ECU ASSEMBLY

B

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

Lost Communication with Gateway Module (U1002)

DESCRIPTION

This DTC is stored when the driving support ECU assembly cannot receive signals from the forward recognition camera or millimeter wave radar sensor assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
• After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

  Click here

• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

• When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.
• If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition camera adjustment.

  Click here

HINT:

• Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
• Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

(c) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition Result G39-8 (CA1P) - G39-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 54 Ω: Short circuit between bus lines 70 Ω or more: Open circuit in a main bus line or driving support ECU assembly branch line G39-8 (CA1P) - G39-28 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short G39-9 (CA1N) - G39-28 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short G39-8 (CA1P) - G39-7 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short G39-9 (CA1N) - G39-7 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short

*a Component with harness connected (Driving Support ECU Assembly)

B

GO TO STEP 3

C

GO TO STEP 8

D

GO TO STEP 12

A

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

USE SIMULATION METHOD TO CHECK

B

REPLACE DRIVING SUPPORT ECU ASSEMBLY

(a) Disconnect the G39 driving support ECU assembly connector.

*a Front view of wire harness connector (to Driving Support ECU Assembly)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

HINT:

If the resistance is between 108 and 132 Ω, there may be an open in a CAN bus main line. If the value is 132 Ω or more, there may be an open in a CAN bus branch line between the No. 8 CAN junction connector and the driving support ECU assembly or a connector may be disconnected.

(c) Connect the G39 driving support ECU assembly connector.

NG

GO TO STEP 7

OK

(a) Disconnect the G92 No. 8 CAN junction connector.

*a Front view of wire harness connector (to No. 8 CAN Junction Connector) *b to Forward Recognition Camera *c to Millimeter Wave Radar Sensor Assembly

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the G92 No. 8 CAN junction connector.

A

REPLACE NO. 8 CAN JUNCTION CONNECTOR

C

GO TO STEP 6

B

(a) Disconnect the O5 forward recognition camera connector.

*a Front view of wire harness connector (to Forward Recognition Camera)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the O5 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

(a) Disconnect the A25 millimeter wave radar sensor assembly connector.

*a Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the A25 millimeter wave radar sensor assembly connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

(a) Disconnect the G39 driving support ECU assembly connector.

*a Front view of wire harness connector (to Driving Support ECU Assembly)

(b) Disconnect the G92 No. 8 CAN junction connector.

*a Front view of wire harness connector (to No. 8 CAN Junction Connector) *b to Driving Support ECU Assembly

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(d) Connect the G92 No. 8 CAN junction connector.

(e) Connect the G39 driving support ECU assembly connector.

OK

REPLACE NO. 8 CAN JUNCTION CONNECTOR

NG

REPAIR OR REPLACE CAN BUS BRANCH WIRE (NO. 8 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY)

(a) Disconnect the O5 forward recognition camera connector.

*a Front view of wire harness connector (to Forward Recognition Camera)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the O5 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

(a) Disconnect the G92 No. 8 CAN junction connector.

*a Front view of wire harness connector (to No. 8 CAN Junction Connector) *b to Forward Recognition Camera *c to Millimeter Wave Radar Sensor Assembly *d to Driving Support ECU Assembly

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the G92 No. 8 CAN junction connector.

A

REPLACE NO. 8 CAN JUNCTION CONNECTOR

B

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

D

GO TO STEP 11

C

(a) Disconnect the A25 millimeter wave radar sensor assembly connector.

*a Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the A25 millimeter wave radar sensor assembly connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

(a) Disconnect the G39 driving support ECU assembly connector.

*a Front view of wire harness connector (to Driving Support ECU Assembly)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the G39 driving support ECU assembly connector.

OK

REPLACE DRIVING SUPPORT ECU ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS BRANCH LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY)

(a) Disconnect the O5 forward recognition camera connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the O5 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

(a) Disconnect the G92 No. 8 CAN junction connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the G92 No. 8 CAN junction connector.

A

REPLACE NO. 8 CAN JUNCTION CONNECTOR

B

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

D

GO TO STEP 15

C

(a) Disconnect the A25 millimeter wave radar sensor assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the A25 millimeter wave radar sensor assembly connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

(a) Disconnect the G39 driving support ECU assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the G39 driving support ECU assembly connector.

OK

REPLACE DRIVING SUPPORT ECU ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS BRANCH LINE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - DRIVING SUPPORT ECU ASSEMBLY)

Lost Communication with Driving Support ECU (U1104)

DESCRIPTION

The driving support ECU assembly is connected to the millimeter wave radar sensor assembly, forward recognition camera and skid control ECU (brake actuator assembly) via CAN communication. If communication with the millimeter wave radar sensor assembly, forward recognition camera or skid control ECU (brake actuator assembly) stops, the driving support ECU assembly stores DTC U1104.

HINT:

DTC will be stored when conditions of any pattern in the table above are met.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Inspect the fuses for circuits related to this system before performing the following procedure.
• Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
• After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

  Click here

• When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.
• If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition camera adjustment.

  Click here

• When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
• When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

  Click here

• Confirm that the connectors are securely connected, as a partially connected connector can cause this DTC to be stored.

PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: System Select / Can Bus Check.

Click here

B

GO TO CAN COMMUNICATION SYSTEM

A

(a) Check for DTCs.

B

GO TO STEP 6

C

REPLACE DRIVING SUPPORT ECU ASSEMBLY

D

GO TO STEP 7

A

(a) Check for DTCs.

B

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

A

NOTICE:

Perform Test Mode (Signal Check) with the vehicle stopped.

HINT:

When entering Test Mode (Signal Check), the skid control ECU (brake actuator assembly) communicates with the driving support ECU assembly to judge whether the vehicle is equipped with the pre-collision system. Therefore, do not exit Test Mode (Signal Check) within 5 seconds of entering Test Mode (Signal Check).

(a) Procedure to enter Test Mode (Signal Check)

(1) Turn the engine switch off.

(2) Check that the steering wheel is centered.

(3) Apply the parking brake.

(4) Check that the shift lever is in P.

(5) Connect the Techstream to the DLC3.

(6) Turn the engine switch on (IG).

(7) Turn the Techstream on.

(8) Switch the skid control ECU (brake actuator assembly) to Test Mode (Signal Check) using the Techstream. Enter the following menus: Chassis / ABS/VSC/TRAC/EPB / Utility / Signal Check.

HINT:

Do not exit Test Mode (Signal Check) within 5 seconds of entering Test Mode (Signal Check). If Test Mode (Signal Check) is exited within 5 seconds of entering Test Mode (Signal Check), DTC U1104 may be stored. If DTC U1104 is output after exiting Test Mode (Signal Check), enter Test Mode (Signal Check) again, wait at least 5 seconds, then recheck for DTCs.

(9) Check that the ABS warning and slip indicator lights come on for several seconds and the ABS warning, slip indicator and parking brake indicator lights blink in the Test Mode pattern.

HINT:

• If the ABS warning, slip indicator and parking brake indicator lights do not blink, inspect the ABS warning, slip indicator and parking brake indicator light circuits.
• While the parking brake is engaged, the parking brake indicator light illuminates but does not blink in the Test Mode pattern.

(b) End of Test Mode (Signal Check)

(1) End Test Mode (signal check) using the Techstream

1. Turn the engine switch off and enter normal mode.
2. Remove the Techstream.

NEXT

(a) Clear the DTCs.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

A

END

B

REPLACE DRIVING SUPPORT ECU ASSEMBLY

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

(c) Disconnect the O5 forward recognition camera connector.

*a Front view of wire harness connector (to Forward Recognition Camera)

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

HINT:

If the result is not as specified, a malfunction in a CAN communication line is suspected.

(e) Connect the O5 forward recognition camera connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

(c) Disconnect the O5 forward recognition camera connector.

*a Front view of wire harness connector (to Forward Recognition Camera)

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

HINT:

If the result is not as specified, a malfunction in a CAN communication line is suspected.

(e) Connect the O5 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

Utility

UTILITY

NOTICE:

• When replacing a millimeter wave radar sensor assembly, replace it with a new one. When the millimeter wave radar sensor assembly is replaced with a new one, it stores the country specification information received from the driving support ECU assembly.

  If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle and a DTC may be stored.

• If the millimeter wave radar sensor assembly has been replaced or removed/installed, be sure to perform Front Beam Axis Adjustment. If not performed, DTC C1A14 will be stored when the system is turned on.

CONTROL MODE

HINT:

• This mode is used to check the operation of the pre-collision system when reproducing situations when the pre-collision system operated unnecessarily.
• Operating the pre-collision brake assist control or pre-collision braking control when reproducing problem symptoms may lead to a dangerous situation. To avoid this, do not attempt to operate the pre-collision braking control, only operate the pre-collision warning control (buzzer and warning message) when reproducing the problem symptoms.

  PCS Control Operated	Buzzer Sound
  Pre-collision warning control	Intermittent (Long)
  Pre-collision brake assist control	Intermittent (Short)
  Pre-collision braking control	Continuous

(a) Connect the Techstream to the DLC3.

(b) Enter the following menus: Body Electrical / Pre-Collision 2 / Utility / Control Mode.

(c) Perform Control Mode according to the display on the Techstream.

FRONT BEAM AXIS ADJUSTMENT

HINT:

Front Beam Axis Adjustment of the millimeter wave radar sensor assembly is performed using the Techstream.

(a) Perform Front Beam Axis Adjustment according to the display on the Techstream.

Click here

FRONT BEAM AXIS MISALIGNMENT READING

HINT:

The amount of misalignment of the millimeter wave radar sensor assembly can be checked using the Techstream.

(a) Perform Front Beam Axis Misalignment Reading according to the display on the Techstream.

Click here

FRONT BEAM AXIS OFFSET READING

HINT:

The offset of the millimeter wave radar sensor assembly can be checked using the Techstream.

(a) Perform Front Beam Axis Offset Reading according to the display on the Techstream.

Click here

HISTORY CLEAR

HINT:

If the status of any history data is "ON", clear the history data.

(a) Connect the Techstream to the DLC3.

(b) Enter the following menus: Body Electrical / Pre-Collision 2 / Utility / History Clear.

(c) Perform History Clear according to the display on the Techstream.

Vehicle Control History

VEHICLE CONTROL HISTORY

VEHICLE CONTROL HISTORY

(a) A part of the control history can be confirmed using the vehicle control history.

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