Toyota Avalon (XX50): Power Source Mode does not Change to ON (IG and ACC)

DESCRIPTION

When the engine switch cannot be turned on (ACC) or on (IG), interior verification may be abnormal or there may be a malfunction in the ACC relay or IG relay circuit. If interior verification cannot be performed, the certification ECU (smart key ECU assembly) may be malfunctioning or communication may not be possible between the No. 1 indoor electrical key antenna assembly (front floor) or No. 1 indoor electrical key antenna assembly (rear floor) and the electrical key transmitter sub-assembly and door control receiver.

When an electrical key transmitter sub-assembly is brought into the cabin, its key ID code is compared with the key ID code stored in the certification ECU (smart key ECU assembly). If these codes do not match, key verification will fail and the engine switch will not be able to be turned on (ACC) or on (IG).

When a door is unlocked and an electrical key transmitter sub-assembly is brought into the cabin, the certification ECU (smart key ECU assembly) activates the indoor electrical key antenna assemblies to form the interior detection area. The electrical key transmitter sub-assembly then responds to the detection signals with its key ID code. This response signal is received by the door control receiver and sent to the certification ECU (smart key ECU assembly).

Related Data List and Active Test Items

Problem Symptom	Data List and Active Test
Power source mode does not change to on (IG) or on (ACC)	Power Source Control Start Switch1 Start Switch2 IG Relay Monitor (Inside) ACC Relay Monitor IG Relay Monitor (Outside) Latch Circuit Power Supply Condition Starting Control Ignition

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• When using the Techstream with the engine 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, Gasoline 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, Gasoline Model) after confirming that the communication systems are functioning properly.

  Click here

• Make sure that no DTCs are output. If any DTCs are output, proceed to Diagnostic Trouble Code Chart.
• If the smart key system (for Start Function, Gasoline Model) has been disabled, enable the system before performing troubleshooting.

  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) or an electrical key transmitter sub-assembly, refer to Registration.

  Click here

• After completing repairs, confirm that the problem does not recur.
• After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."
• The indoor electrical key antenna assemblies have an antenna coil between each terminal.
• The door control receiver is also related to interior certification.

HINT:

• If interior verification is unsuccessful, Operation History may be stored.
• If Operation History has been stored, refer to the Operation History List to determine the detection conditions and narrow down trouble areas.

Body Electrical > Smart Key > Utility

Tester Display
Operation History

PROCEDURE

1.	CHECK POWER SOURCE MODE

(a) Get into the vehicle while carrying the electrical key transmitter sub-assembly that has already been registered.

(b) Move the shift lever to P.

(c) Press the engine switch with the brake pedal released and check that the power source mode changes.

Click here

Result	Proceed to
Power source mode can only be changed when electrical key transmitter sub-assembly is in push button start function operation range for rear side	A
Power source mode can only be changed when electrical key transmitter sub-assembly is in push button start function operation range for front side	B
Power source mode cannot be changed	C

B

GO TO STEP 6

C

GO TO STEP 10

A

2.	CHECK WAVE ENVIRONMENT

(a) Install the transmitter battery to the electrical key transmitter sub-assembly.

Click here

(b) Bring the electrical key transmitter sub-assembly near the No. 1 indoor electrical key antenna assembly (front floor) and perform an smart key system check.

Click here

NOTICE:

Communication may not be possible if the electrical key transmitter sub-assembly is within 0.2 m (0.656 ft.) of the No. 1 indoor electrical key antenna assembly (front floor).

HINT:

• As the effect of wave interference decreases by moving the electrical key transmitter sub-assembly close to each indoor electrical key antenna assembly, it may be possible to check whether wave interference is the cause of the problem.
• If the inspection result is that the problem only occurs in certain locations or at certain times of day, the possibility of wave interference is high. Also, added vehicle components may cause wave interference. If installed, remove them and perform the operation check.
• There may be wave interference if the vehicle is near broadcasting antennas, large video displays, wireless garage door opener systems, wireless security cameras, home security systems, etc. In this case, move the vehicle to a different location and check if there is any improvement.
• If a tool for checking radio waves, such as a signal strength meter, is available, move around the area while observing both the LF band (used by the vehicle antenna to form the detection area) and RF band (used by the electrical key transmitter sub-assembly for transmission) to check for locations where there is wave interference.

OK:

The engine starts when the electrical key transmitter sub-assembly is held near each indoor electrical key antenna assembly and the engine switch is pressed with the brake pedal depressed.

OK

AFFECTED BY WAVE INTERFERENCE

NG

3.	CHECK KEY DIAGNOSTIC MODE

(a) Check the following antennas in key diagnostic mode.

(b) Check the No. 1 indoor electrical key antenna assembly (front floor). When the electrical key transmitter sub-assembly is at either inspection point, check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and perform the key diagnostic mode inspection for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference. It is possible to check which indoor electrical key antenna assembly (front floor, rear floor or inside luggage compartment) is operating by the sounding of the buzzer. When the wireless buzzer sounds for all indoor electrical key antenna assemblies, they can be judged as operating properly and a malfunction in the certification ECU (smart key ECU assembly), which performs verification, is suspected. When the wireless buzzer does not sound for all indoor electrical key antenna assemblies, it can be judged that the certification ECU (smart key ECU assembly), which controls the indoor electrical key antenna assemblies, is malfunctioning. Body Electrical > Smart Key > Utility Tester Display Communication Check(Key Diag Mode)

*a Inspection Point

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

AFFECTED BY WAVE INTERFERENCE

A

4.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR))

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

(b) Disconnect the G42 No. 1 indoor electrical key antenna assembly (front floor) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-8 (CLG5) - G42-1 (ANTE5)	Always	Below 1 Ω
G40-9 (CG5B) - G42-3 (CLGB)	Always	Below 1 Ω
G40-8 (CLG5) or G42-1 (ANTE5) - Other terminals and body ground	Always	10 kΩ or higher
G40-9 (CG5B) or G42-3 (CLGB) - Other terminals and body ground	Always	10 kΩ or higher

(d) Reconnect the G40 certification ECU (smart key ECU assembly) connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR))

(a) Using an oscilloscope, check the waveform.

*a	Front view of wire harness connector (to No. 1 Indoor Electrical Key Antenna Assembly (Front Floor))	*b	Waveform
*c	For 30 seconds after closing any door	*d	After 30 seconds or more have elapsed since any door closed

OK:

Tester Connection	Condition	Tool Setting	Specified Condition
G42-1 (ANTE5) - G42-3 (CLGB)	Procedure: Engine switch off Electrical key transmitter sub-assembly not inside vehicle Within 30 seconds of closing any door	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)

OK

REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

6.	CHECK WAVE ENVIRONMENT

(a) Install the transmitter battery to the electrical key transmitter sub-assembly.

Click here

(b) Bring the electrical key transmitter sub-assembly near the No. 1 indoor electrical key antenna assembly (rear floor) and perform an smart key system check.

Click here

NOTICE:

Communication may not be possible if the electrical key transmitter sub-assembly is within 0.2 m (0.656 ft.) of the center of the No. 1 indoor electrical key antenna assembly (rear floor).

HINT:

Check that the customize setting "Ignition Available Area" is set to "All".

HINT:

• As the effect of wave interference decreases by moving the electrical key transmitter sub-assembly close to each indoor electrical key antenna assembly, it may be possible to check whether wave interference is the cause of the problem.
• If the inspection result is that the problem only occurs in certain locations or at certain times of day, the possibility of wave interference is high. Also, added vehicle components may cause wave interference. If installed, remove them and perform the operation check.
• There may be wave interference if the vehicle is near broadcasting antennas, large video displays, wireless garage door opener systems, wireless security cameras, home security systems, etc. In this case, move the vehicle to a different location and check if there is any improvement.
• If a tool for checking radio waves, such as a signal strength meter, is available, move around the area while observing both the LF band (used by the vehicle antenna to form the detection area) and RF band (used by the electrical key transmitter sub-assembly for transmission) to check for locations where there is wave interference.

OK:

The engine starts when the electrical key transmitter sub-assembly is held near each indoor electrical key antenna assembly and the engine switch is pressed with the brake pedal depressed.

OK

AFFECTED BY WAVE INTERFERENCE

NG

7.	CHECK KEY DIAGNOSTIC MODE

(a) Check the following antennas in key diagnostic mode.

(b) Check the No. 1 indoor electrical key antenna assembly (rear floor). When the electrical key transmitter sub-assembly is at either inspection point, check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and perform the key diagnostic mode inspection for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference. It is possible to check which indoor electrical key antenna assembly (front floor, rear floor or inside luggage compartment) is operating by the sounding of the buzzer. When the wireless buzzer sounds for all indoor electrical key antenna assemblies, they can be judged as operating properly and a malfunction in the certification ECU (smart key ECU assembly), which performs verification, is suspected. When the wireless buzzer does not sound for all indoor electrical key antenna assemblies, it can be judged that the certification ECU (smart key ECU assembly), which controls the indoor electrical key antenna assemblies, is malfunctioning. Body Electrical > Smart Key > Utility Tester Display Communication Check(Key Diag Mode)

*a Inspection Point

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

AFFECTED BY WAVE INTERFERENCE

A

8.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR))

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

(b) Disconnect the K12 No. 1 indoor electrical key antenna assembly (rear floor) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
K10-5 (CLG6) - K12-1 (ANTE6)	Always	Below 1 Ω
K10-6 (CG6B) - K12-3 (CLGB)	Always	Below 1 Ω
K10-5 (CLG6) or K12-1 (ANTE6) - Other terminals and body ground	Always	10 kΩ or higher
K10-6 (CG6B) or K12-3 (CLGB) - Other terminals and body ground	Always	10 kΩ or higher

(d) Reconnect the K10 certification ECU (smart key ECU assembly) connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR))

(a) Using an oscilloscope, check the waveform.

*a	Front view of wire harness connector (to No. 1 Indoor Electrical Key Antenna Assembly (Rear Floor))	*b	Waveform
*c	For 30 seconds after closing any door	*d	After 30 seconds or more have elapsed since any door closed

OK:

Tester Connection	Condition	Tool Setting	Specified Condition
K12-1 (ANTE6) - K12-3 (CLGB)	Procedure: Engine switch off Electrical key transmitter sub-assembly not inside vehicle Within 30 seconds of closing any door	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)

OK

REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

10.	INSPECT TRANSMITTER BATTERY

(a) Check the transmitter battery level of the electrical key transmitter sub-assembly that was checked first.

(1) Press and hold the lock switch of the electrical key transmitter sub-assembly for 5 seconds and check the number of times that the LED illuminates.

HINT:

• The electrical key transmitter sub-assembly sends voltage information to the certification ECU (smart key ECU assembly) when it is being used. "Yes" is displayed for the Data List item Key Low Battery when this voltage information indicates 2.2 V or less.

  Click here

• Even if the transmitter battery is depleted, it is still possible to start the engine by holding the electrical key transmitter sub-assembly near the engine switch, depressing the brake pedal and pressing the engine switch.

Result	Proceed to
LED illuminates 3 times or more when switch is pressed and held	A
LED does not illuminate when switch is pressed and held	B
LED illuminates once or twice but not a third time	C

B

GO TO STEP 19

C

REPLACE TRANSMITTER BATTERY

A

11.	CHECK ENTRY LOCK / UNLOCK OPERATION

(a) Check that the entry lock and unlock functions operate on each door.

Click here

HINT:

If the door control receiver is defective, code verification does not begin in the cabin and the entry lock and unlock functions do not operate.

Result	Proceed to
Entry functions operate normally for all doors (w/ Wireless Charging System)	A
Entry functions operate normally for all doors (w/o Wireless Charging System)	B
An entry function does not operate normally for a door	C

B

GO TO STEP 13

C

GO TO SMART KEY SYSTEM (for Entry Function, Gasoline Model) (All Door Entry Lock/Unlock Functions and Wireless Functions do not Operate)

A

12.	CHECK WIRELESS CHARGING SYSTEM

(a) Wireless charging system off.

Click here

(b) Check that interior verification is performed.

Click here

Result	Proceed to
Interior verification is not performed normally	A
Interior verification is performed normally	B

B

GO TO WIRELESS CHARGING SYSTEM

A

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

(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 / 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	Engine switch 1 status	OFF or ON	OFF: Engine switch not pressed ON: Engine switch pressed	If the engine switch is pressed for a short time, the display may not change. Use this item to determine if the engine switch input signal is malfunctioning.
Start Switch2	Engine switch 2 status	OFF or ON	OFF: Engine switch not pressed ON: Engine switch pressed	Backup for engine switch 1. However, when the engine switch is pressed and held, the control functions only when both engine switch 1 and 2 are normal. Behaves the same way as engine switch 1.

Body Electrical > Power Source Control > Data List

Tester Display
Start Switch1
Start Switch2

OK:

The value of "Start Switch1" and "Start Switch2" change correctly in response to the engine switch operation.

NG

GO TO STEP 17

OK

14.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Measure the voltage while checking the Data List on the Techstream.

(1) Connect the Techstream to the DLC3.

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

(3) Turn the Techstream on.

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

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

*a

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

-

-

Body Electrical > Power Source Control > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Power Supply Condition	Power supply state	All OFF, ACC ON, IG ON or ST ON	All OFF: Engine switch off (ACC and IG) ACC ON: Engine switch on (ACC) IG ON: Engine switch on (IG) ST ON: Sending engine start request signal	-

Body Electrical > Power Source Control > Data List

Tester Display
Power Supply Condition

(6) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
G40-17 (IG1D) - Body ground	Engine switch off	Below 1 V
	Engine switch on (ACC)	Below 1 V
	Engine switch on (IG)	9 V or higher
G40-16 (ACCD) - Body ground	Engine switch off	Below 1 V
	Engine switch on (ACC)	8.5 V or higher
	Engine switch on (IG)	8.5 V or higher

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK

15.	CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1-NO. 1, IG1-NO. 2, IG2-NO. 2, ACC RELAY)

(a) Remove the instrument panel junction block assembly.

Click here

(b) Connect all of the instrument panel junction block assembly connectors.

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

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

Standard Voltage:

Tester Connection	Condition	Specified Condition
4H-26 - Body ground	Engine switch on (ACC)	11 to 14 V
4H-35 - Body ground	Engine switch on (IG)	11 to 14 V
4F-2 - Body ground	Engine switch on (IG)	11 to 14 V
4F-15 - Body ground	Engine switch on (IG)	11 to 14 V

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

16.	CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)

(a) Disconnect the 4D instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4D-3 - Body ground	Always	Below 1 Ω

OK

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	INSPECT ENGINE SWITCH

(a) Remove the engine switch.

Click here

(b) Inspect the engine switch.

Click here

NG

REPLACE ENGINE SWITCH

OK

18.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE SWITCH)

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-23 (SSW1) - G41-5 (SS1)	Always	Below 1 Ω
G40-21 (SSW2) - G41-1 (SS2)	Always	Below 1 Ω
G40-11 (AGND) - G41-6 (AGND)	Always	Below 1 Ω
G40-23 (SSW1) or G41-5 (SS1) - Other terminals and body ground	Always	10 kΩ or higher
G40-21 (SSW2) or G41-1 (SS2) - Other terminals and body ground	Always	10 kΩ or higher
G40-11 (AGND) or G41-6 (AGND) - Other terminals and body ground	Always	10 kΩ or higher

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

19.	INSPECT TRANSMITTER BATTERY

(a) Inspect the transmitter battery.

Click here

NOTICE:

Do not wrap the lead wire ground a terminal, wedge it between terminals, or solder it. The terminal may be deformed or damaged, and the transmitter battery will not be able to be installed correctly.

OK

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

NG

REPLACE TRANSMITTER BATTERY