Toyota Avalon (XX50): Engine/Power Switch Malfunction (B2278). Vehicle Speed Signal Malfunction (B2282,B2283). Brake Signal Malfunction (B2284)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System(for Start Function, Hv Model) / Engine/Power Switch Malfunction (B2278). Vehicle Speed Signal Malfunction (B2282,B2283). Brake Signal Malfunction (B2284)

Engine/Power Switch Malfunction (B2278)

DESCRIPTION

This DTC is stored when the SSW1 contact signal and SSW2 contact signal, which are detected when the power switch is operated, do not match.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2278	Engine/Power Switch Malfunction	When the power switch is operated, the SSW1 contact signal and SSW2 contact signal do not match (1-trip detection logic*).	Power switch Certification ECU (smart key ECU assembly) Wire harness or connector	Turn the power switch on (IG).

*: Only detected while a malfunction is present.

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Function when Malfunction Detected
If either the SSW1 contact signal or SSW2 contact signal is stuck on, the power source mode cannot be changed by pressing the power switch. If either the SSW1 contact signal or SSW2 contact signal is stuck off, emergency stop by pressing and holding the power switch for 2 seconds or more cannot be operated.	-

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B2278	Power Source Control Start Switch1 Start Switch2

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function, HV Model) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function, HV Model) after confirming that the communication systems are functioning properly.
Click here
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	READ VALUE USING TECHSTREAM (START SWITCH1, START SWITCH2)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Power Source Control / Data List.

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

Body Electrical > Power Source Control > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Start Switch1	Power switch 1 status	OFF or ON	OFF: Power switch not pressed ON: Power switch pressed	If the power switch is pressed for a short time, the display may not change. Use this item to determine if the power switch input signal is malfunctioning.
Start Switch2	Power switch 2 status	OFF or ON	OFF: Power switch not pressed ON: Power switch pressed	Backup for power switch 1. However, when the power switch is pressed and held, the control functions only when both power switch 1 and 2 are normal. Behaves the same way as power switch 1.

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Start Switch1

Power switch 1 status

OFF or ON

OFF: Power switch not pressed

ON: Power switch pressed

If the power switch is pressed for a short time, the display may not change.
Use this item to determine if the power switch input signal is malfunctioning.

Start Switch2

Power switch 2 status

OFF or ON

OFF: Power switch not pressed

ON: Power switch pressed

Backup for power switch 1. However, when the power switch is pressed and held, the control functions only when both power switch 1 and 2 are normal.
Behaves the same way as power switch 1.

Body Electrical > Power Source Control > Data List

Tester Display
Start Switch1
Start Switch2

OK:

The Techstream display changes correctly in response to the power switch operation.

GO TO STEP 3

2.	READ VALUE USING TECHSTREAM (START SWITCH1, START SWITCH2)

(a) Enter the following menus: Body Electrical / Power Source Control / Data List.

(b) According to the display on the Techstream, read the Data List while wiggling the wire harness.

Body Electrical > Power Source Control > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Start Switch1	Power switch 1 status	OFF or ON	OFF: Power switch not pressed ON: Power switch pressed	If the power switch is pressed for a short time, the display may not change. Use this item to determine if the power switch input signal is malfunctioning.
Start Switch2	Power switch 2 status	OFF or ON	OFF: Power switch not pressed ON: Power switch pressed	Backup for power switch 1. However, when the power switch is pressed and held, the control functions only when both power switch 1 and 2 are normal. Behaves the same way as power switch 1.

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Start Switch1

Power switch 1 status

OFF or ON

OFF: Power switch not pressed

ON: Power switch pressed

If the power switch is pressed for a short time, the display may not change.
Use this item to determine if the power switch input signal is malfunctioning.

Start Switch2

Power switch 2 status

OFF or ON

OFF: Power switch not pressed

ON: Power switch pressed

Backup for power switch 1. However, when the power switch is pressed and held, the control functions only when both power switch 1 and 2 are normal.
Behaves the same way as power switch 1.

Body Electrical > Power Source Control > Data List

Tester Display
Start Switch1
Start Switch2

OK:

The Techstream display changes correctly in response to the power switch operation.

USE SIMULATION METHOD TO CHECK

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - POWER SWITCH)

(a) Disconnect the G40 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the G117 power switch connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-23 (SSW1) - G117-5 (SS1)	Always	Below 1 Ω
G40-21 (SSW2) - G117-1 (SS2)	Always	Below 1 Ω
G40-11 (AGND) - G117-6 (AGND)	Always	Below 1 Ω
G40-23 (SSW1) or G117-5 (SS1) - Other terminals and body ground	Always	10 kΩ or higher
G40-21 (SSW2) or G117-1 (SS2) - Other terminals and body ground	Always	10 kΩ or higher
G40-11 (AGND) or G117-6 (AGND) - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT POWER SWITCH

(a) Remove the power switch.

Click here

(b) Inspect the power switch.

Click here

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE POWER SWITCH

Vehicle Speed Signal Malfunction (B2282,B2283)

DESCRIPTION

DTC B2282 is stored when the vehicle speed signal sent by the combination meter assembly via direct line and the vehicle speed signal sent via CAN communication do not match.

DTC B2283 is stored when a malfunction in the vehicle speed sensor is detected.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2282	Vehicle Speed Signal Malfunction	The vehicle speed signal sent by the combination meter assembly via direct line and the vehicle speed signal sent via CAN communication do not match. (1-trip detection logic*)	Meter/gauge system Certification ECU (smart key ECU assembly) Wire harness or connector	Drive the vehicle at a vehicle speed of 25 km/h (16 mph) or more for 20 seconds, and then drive the vehicle at a vehicle speed of less than 5 km/h (3 mph) for 20 seconds.
B2283	Vehicle Speed Sensor Malfunction	Vehicle speed signal malfunction is detected (excessive deceleration is detected). (1-trip detection logic*)	Meter/gauge system Certification ECU (smart key ECU assembly) Wire harness or connector	Drive the vehicle at a vehicle speed of 50 km/h (31 mph) or more for 10 seconds, and then drive the vehicle at a vehicle speed of less than 50 km/h (31 mph).

*: Only detected while a malfunction is present and the power switch is on (IG).

Vehicle Condition and Fail-safe Function when Malfunction Detected

DTC Code	Vehicle Condition when Malfunction Detected	Fail-safe Function when Malfunction Detected
B2282	When the signal sent via either direct line or CAN communication is malfunctioning and indicates that the vehicle speed is 0 km/h (0 mph), there is no effect on vehicle behavior. When the signal sent via either direct line or CAN communication is malfunctioning and indicates that the vehicle is moving, the power switch cannot be turned from on (IG) to off.	-
B2283	The power source mode is changed to off (the hybrid control system is stopped) by pressing the power switch while the vehicle is being driven. With the electrical key transmitter sub-assembly in the cabin, even if a hybrid control system start operation is performed, the hybrid control system will not start.	Steering lock motor operation is prohibited.

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B2282 B2283	Power Source Control Vehicle Speed Signal Power Supply Condition Combination Meter Vehicle Speed Meter

DTC No.

Data List and Active Test

B2282

B2283

Power Source Control

Vehicle Speed Signal
Power Supply Condition

Combination Meter

Vehicle Speed Meter

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function, HV Model) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function, HV Model) after confirming that the communication systems are functioning properly.
Click here
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	READ VALUE USING TECHSTREAM (VEHICLE SPEED METER)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

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

Body Electrical > Combination Meter > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Vehicle Speed Meter	Vehicle speed	Min.: 0, Max.: 255	Almost same as actual vehicle speed (Speedometer tester)	-

Body Electrical > Combination Meter > Data List

Tester Display
Vehicle Speed Meter

HINT:

Using a speedometer tester, check the actual vehicle speed and the vehicle speed displayed on the Techstream.

OK:

Vehicle speed displayed on the Techstream is almost the same as the actual vehicle speed measured using a speedometer tester.

GO TO METER / GAUGE SYSTEM (Speedometer Malfunction)

2.	READ VALUE USING TECHSTREAM (VEHICLE SPEED SIGNAL)

(a) Enter the following menus: Body Electrical / Power Source Control / Data List.

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

Body Electrical > Power Source Control > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Vehicle Speed Signal	Vehicle being driven or stopped	Stop or Run	Stop: Vehicle stopped Run: Vehicle being driven at 5 km/h (3 mph) or more	-

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Vehicle Speed Signal

Vehicle being driven or stopped

Stop or Run

Stop: Vehicle stopped

Run: Vehicle being driven at 5 km/h (3 mph) or more

Body Electrical > Power Source Control > Data List

Tester Display
Vehicle Speed Signal

OK:

The Techstream display changes correctly in response to the vehicle condition.

GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

3.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - COMBINATION METER ASSEMBLY)

(a) Disconnect the G16 combination meter assembly connector.

(b) Disconnect the G40 certification ECU (smart key ECU assembly) connector.

(d) Disconnect the G9 DCM (telematics transceiver) connector.

(e) Disconnect the G13 navigation ECU connector.*1

(f) Disconnect the A39 brake actuator assembly connector.

(g) Disconnect the G8 stereo component amplifier assembly connector.*2

(h) Disconnect the G38 vehicle approaching speaker controller connector.

*1: w/ Navigation System
*2: for 14 Speakers

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-19 (SPD) - G16-6 (+S)	Always	Below 1 Ω
G40-19 (SPD) or G16-6 (+S) - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Connect the G40 certification ECU (smart key ECU assembly) connector.

(b) Connect the G16 combination meter assembly connector.

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

Tester Connection	Condition	Tool Setting	Specified Condition
G40-19 (SPD) - G40-18 (E)	Power switch on (IG), vehicle being driven at approx. 5 km/h (3 mph)	5 V/DIV., 20 ms./DIV.	Pulse generation

HINT:

The wavelength becomes shorter as the vehicle speed increases.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

GO TO METER / GAUGE SYSTEM (Speed Signal Circuit)

Brake Signal Malfunction (B2284)

DESCRIPTION

This DTC is stored when the brake signal sent via direct line and the brake signal sent via CAN communication do not match.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2284	Brake Signal Malfunction	The brake signal sent via direct line and the brake signal sent via CAN communication do not match. (1-trip detection logic*)	Electronically controlled brake system Stop light switch assembly Certification ECU (smart key ECU assembly) Wire harness or connector	Connect the cable to the negative (-) auxiliary battery terminal, release the brake pedal and wait at least 20 seconds. Then depress the brake pedal for 20 seconds or more.

*: Only detected while a malfunction is present and the power switch is on (IG).

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Function when Malfunction Detected
With the electrical key transmitter sub-assembly in the cabin, even if a hybrid control system start operation is performed, the hybrid control system does not start (the key indicator display is not displayed on the multi-information display). However, the hybrid control system can be started by turning the power switch on (ACC) and then pressing and holding it. If there is a malfunction when the brake signal sent via direct line is on, the hybrid control system can be started by pressing the power switch with the brake pedal released. If there is a malfunction when the brake signal sent via direct line is off, the hybrid control system cannot be started by pressing the power switch with the brake pedal depressed.	-

Vehicle Condition when Malfunction Detected

Fail-safe Function when Malfunction Detected

With the electrical key transmitter sub-assembly in the cabin, even if a hybrid control system start operation is performed, the hybrid control system does not start (the key indicator display is not displayed on the multi-information display). However, the hybrid control system can be started by turning the power switch on (ACC) and then pressing and holding it.

If there is a malfunction when the brake signal sent via direct line is on, the hybrid control system can be started by pressing the power switch with the brake pedal released.
If there is a malfunction when the brake signal sent via direct line is off, the hybrid control system cannot be started by pressing the power switch with the brake pedal depressed.

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B2284	Power Source Control Stop Light Switch1 Hybrid Control Stop Light Switch

DTC No.

Data List and Active Test

B2284

Power Source Control

Stop Light Switch1

Hybrid Control

Stop Light Switch

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function, HV Model) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function, HV Model) after confirming that the communication systems are functioning properly.
Click here
Inspect the fuses of circuits related to this system before performing the following procedure.
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH1)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Power Source Control / Data List.

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

Body Electrical > Power Source Control > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Stop Light Switch1

State of brake pedal

OFF or ON

OFF: Brake pedal released

ON: Brake pedal depressed

Use this item to determine if the stop light switch assembly is malfunctioning.
The hybrid control system cannot be started when this item is OFF.
If the stop light switch assembly is malfunctioning, the hybrid control system can be started by pressing and holding the power switch for a certain period of time.

Body Electrical > Power Source Control > Data List

Tester Display
Stop Light Switch1

OK:

The Techstream display changes correctly in response to the brake pedal operation.

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

2.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)

(a) Disconnect the K10 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the A33 stop light switch assembly connector.

(d) Disconnect the A23 hybrid vehicle control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
K10-25 (STP1) - A33-3 (L)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Connect the K10 certification ECU (smart key ECU assembly) connector.

(b) Connect the A33 stop light switch assembly connector.

Standard Voltage:

Tester Connection	Condition	Specified Condition
K10-25 (STP1) - Body ground	Brake pedal released → depressed	1 V or less → 9 V or higher

*a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE STOP LIGHT SWITCH ASSEMBLY

ACC Monitor Malfunction (B2274). STSW Monitor Malfunction (B2275). Detecting Vehicle Submersion (B2277)

Steering Lock Position Signal Circuit Malfunction (B2285). Engine Starter Communication Malfunction (B2779). Open / Short in Steering Lock ECU (B2781)

See More:

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Navigation System(for Gasoline Model): Touch Panel Switch does not Function. USB Audio System Recognition/Play Error. Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter
Touch Panel Switch does not Function CAUTION / NOTICE / HINT NOTICE: Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Navigation System. Click here When replacing the radio ...