Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001APT9
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: SEAT: FRONT POWER SEAT CONTROL SYSTEM (for Gasoline Model with Memory): Front Power Seat does not Operate with Front Power Seat Switch; 2019 - 2022 MY Avalon [04/2018 -        ]

Front Power Seat does not Operate with Front Power Seat Switch

DESCRIPTION

Signals are input into the position control ECU assembly. The built-in ECU manages the signals received from the power seat switch and operates each motor. If the position control ECU assembly receives more than 2 motor operation signals for the same motor, the motor will be stopped. Manual operation resumes when the position control ECU assembly receives only 1 signal.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK FRONT POWER SEAT OPERATION

(a) Check that each function of the power seat operates normally by using the front power seat switch LH.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; SEAT: FRONT POWER SEAT CONTROL SYSTEM (for Gasoline Model with Memory): OPERATION CHECK

Result

Proceed to

All power seat functions do not operate

A

One or more power seat functions do not operate

B
B

GO TO OTHER DIAGNOSIS PROCEDURE (One or more Power Seat Motors do not Operate)

A

2.

INSPECT FRONT POWER SEAT SWITCH LH

(a) Remove the front power seat switch LH.

Click here 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; SEAT: POWER SEAT SWITCH: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; SEAT: POWER SEAT SWITCH: REMOVAL

(b) Inspect the front power seat switch LH.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; SEAT: POWER SEAT SWITCH: INSPECTION

NG

REPLACE FRONT POWER SEAT SWITCH LH 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; SEAT: POWER SEAT SWITCH: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; SEAT: POWER SEAT SWITCH: REMOVAL

OK

3.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - POWER SUPPLY)

(a) Disconnect the R33 and R32 position control ECU assembly connectors.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

R33-3 (B) - Body ground

Always

11 to 14 V

R32-15 (SYSB) - Body ground

Always

11 to 14 V

R32-1 (IG) - Body ground

Engine switch on (IG)

11 to 14 V

R32-1 (IG) - Body ground

Engine switch off

Below 1 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - BODY GROUND)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R33-2 (E) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH LH - BODY GROUND)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R31-20 (E) - Body ground

Always

Below 1 Ω
OK

REPLACE POSITION CONTROL ECU ASSEMBLY 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; SEAT: POWER SEAT CONTROL ECU: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; SEAT: POWER SEAT CONTROL ECU: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR