Toyota Avalon (XX50): Power Source Mode does not Change to ON (READY)

DESCRIPTION

When the electrical key transmitter sub-assembly is in the cabin and the power switch is pressed, the certification ECU (smart key ECU assembly) receives a signal and changes the power source mode. Additionally, when the shift lever is in P and the brake pedal is depressed, the hybrid control system can be started by pressing the power switch. If the steering is unlocked, the hybrid control system can also be started by pressing the power switch with the shift lever in P and the brake pedal depressed.

Related Data List and Active Test Items

Problem Symptom	Data List and Active Test
Power source mode does not change to ON (READY)	Power Source Control Stop Light Switch1 Steering Unlock Switch Shift P Signal IG Relay Monitor (Inside) IG Relay Monitor (Outside) Latch Circuit Starter Request Signal Power Supply Condition Smart Key Immobiliser Engine Start Request L Code Check

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.

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• If the smart key system (for Start Function, HV Model) has been canceled, enable the system before performing troubleshooting.

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• Inspect the fuses of circuits related to this system before performing the following procedure.
• Before replacing the certification ECU (smart key ECU assembly) or electrical key transmitter sub-assembly, refer to Registration.

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• After completing repairs, confirm that the problem does not recur.

PROCEDURE

1.	CHECK POWER SWITCH CONDITION

(a) Get into the vehicle while carrying an electrical key transmitter sub-assembly.

(b) Move the shift lever to P.

(c) With the brake pedal released, check that pressing the power switch causes the power source mode to change.

Result	Proceed to
Power source mode changes : Off → on (ACC) → on (IG) → off	A
Power source mode does not change to on (ACC) or on (IG)	B
Power source mode changes to on (IG) but not to on (ACC)	C
Power source mode changes to on (ACC) but not to on (IG)	D

B

GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (IG and ACC))

C

GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (ACC))

D

GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (IG))

A

2.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH1)

(a) Connect the Techstream to the DLC3.

(b) Turn the power 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
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.

NG

GO TO STEP 7

OK

3.	READ VALUE USING TECHSTREAM (SHIFT P 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
Shift P Signal	Shift position P	OFF or ON	OFF: Shift lever not in P ON: Shift lever in P	Use this item to determine whether the shift lever position switch (P) is malfunctioning.

Body Electrical > Power Source Control > Data List

Tester Display
Shift P Signal

OK:

The Techstream display changes correctly in response to the shift lever operation.

NG

GO TO STEP 9

OK

4.	READ VALUE USING TECHSTREAM (STARTER REQUEST 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
Starter Request Signal	Hybrid control system start request signal status	OFF or ON	OFF: The power switch is not pressed ON: With the shift lever in P and the brake pedal depressed, the power switch is pressed and held	When the hybrid control system cannot be started due to a start request signal malfunction, OFF is displayed. When the power switch is pressed, the duration of time that ON is displayed will be extremely short. As such, the power switch needs to be pressed and held for a certain period of time.

Body Electrical > Power Source Control > Data List

Tester Display
Starter Request Signal

NOTICE:

Check that the key indicator display is displayed on the multi-information display in the combination meter assembly, and then press the power switch.

OK:

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

NG

GO TO STEP 10

OK

5.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - HYBRID VEHICLE CONTROL ECU)

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

(b) Disconnect the G46 hybrid vehicle control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-27 (ST2) - G46-9 (ST2)	Always	Below 1 Ω
G40-27 (ST2) or G46-9 (ST2) - Other terminals and body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

(b) Connect the G46 hybrid vehicle control ECU connector.

(c) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition G40-27 (ST2) - Body ground With the brake pedal depressed, the power switch is pressed and held → After approx. 3 sec. has elapsed, the power switch is released 8.5 V or higher → 1.0 V or less

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

OK

GO TO HYBRID CONTROL SYSTEM

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

7.	CHECK STOP LIGHT SWITCH ASSEMBLY

(a) Check the stop light switch assembly.

Click here

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

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

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

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

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

(d) Disconnect the G21 shift lock control unit assembly connector.

(e) Disconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.

(f) 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
K10-25 (STP1) or A33-3 (L) - 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

9.	CHECK SHIFT LOCK CONTROL UNIT ASSEMBLY

(a) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition G40-22 (P) - Body ground Shift lever in P → Shift lever not in P 9 V or higher → 2.76 V or less

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

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

GO TO STEP 12

10.	CHECK STEERING LOCK FUNCTION

(a) Check that the steering unlocks when the power switch is turned on (ACC).

OK:

The steering unlocks.

NG

GO TO OTHER PROBLEM (Unable to Unlock Steering Wheel (Hybrid Control System cannot Start))

OK

11.	CHECK SECURITY INDICATOR LIGHT (IMMOBILISER FUNCTION UNSET)

(a) Get into the vehicle while carrying an electrical key transmitter sub-assembly.

(b) Move the shift lever to P.

(c) Press the power switch with the brake pedal released and check that the security indicator light changes from blinking to off at the same time that the power source mode changes to on (ACC).

OK:

The security indicator light changes from blinking to off at the same time that the power source mode changes to on (ACC).

HINT:

The immobiliser function can be determined to be operating correctly if the security indicator light changes from blinking to off at the same time that the power source mode changes to on (ACC).

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

GO TO OTHER PROBLEM (Immobiliser System does not Operate Properly)

12.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - SHIFT LOCK CONTROL UNIT ASSEMBLY)

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

(b) Disconnect the G21 shift lock control unit assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-22 (P) - G21-3 (P2)	Always	Below 1 Ω
G40-22 (P) or G21-3 (P2) - Other terminals and body ground	Always	10 kΩ or higher

OK

REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR