Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001APTI
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: SEAT: FRONT POWER SEAT CONTROL SYSTEM (for Gasoline Model with Memory): B2651; Reclining Sensor Malfunction; 2019 - 2022 MY Avalon [04/2018 -        ]

DTC

B2651

Reclining Sensor Malfunction

DESCRIPTION

When the position control ECU assembly does not receive a reclining motor position sensor signal despite the seat having been moved forward or rearward by power seat motor operation, this DTC is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2651

Reclining Sensor Malfunction

Reclining motor position sensor signal not received when power seat moved forward or rearward

  • Position control ECU assembly
  • Reclining motor (front seatback frame sub-assembly LH)
  • Wire harness or connector

WIRING DIAGRAM

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Driver Seat > Clear DTCs

NEXT

2.

CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Driver Seat > Trouble Codes

OK:

DTC B2651 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

3.

PERFORM ACTIVE TEST USING TECHSTREAM (SEAT RECLINING OPERATION)

(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 / Driver Seat / Active Test.

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

Body Electrical > Driver Seat > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Seat Reclining

Seat reclining operation

OFF/Rear/Front

-

Body Electrical > Driver Seat > Active Test

Tester Display

Seat Reclining

OK:

Reclining motor operates normally.

NG

GO TO STEP 7

OK

4.

CHECK POSITION CONTROL ECU ASSEMBLY (RECLINING MOTOR CIRCUIT)

(a) Disconnect the a10 reclining motor (front seatback frame sub-assembly LH) connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

a10-4 (SSRR) - a10-2 (SENG)

Reclining switch on

4.8 to 5.1 V

NG

GO TO STEP 6

OK

5.

CHECK RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH)

(a) Reconnect the a10 reclining motor (front seatback frame sub-assembly LH) connector.

*a

Component with harness connected

(Reclining Motor (Front Seatback Frame Sub-assembly LH))

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

a10-4 (SSRR) - Body ground

Reclining motor operating

4.5 to 4.8 V

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

REPLACE RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH) 2019 - 2020 MY Avalon Avalon HV [04/2018 - 08/2020]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY 2021 - 2022 MY Avalon Avalon HV [08/2020 -        ]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY

6.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH))

(a) Disconnect the R32 position control ECU assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R32-11 (SSRR) - a10-4 (SSRR)

Always

Below 1 Ω

R32-11 (SSRR) or a10-4 (SSRR) - Body ground

Always

10 kΩ or higher

R32-12 (SENG) - a10-2 (SENG)

Always

Below 1 Ω

R32-12 (SENG) or a10-2 (SENG) - Body ground

Always

10 kΩ or higher

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

7.

INSPECT RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH)

(a) Remove the reclining motor (front seatback frame sub-assembly LH).

Click here 2019 - 2020 MY Avalon Avalon HV [04/2018 - 08/2020]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY 2021 - 2022 MY Avalon Avalon HV [08/2020 -        ]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY

(b) Inspect the reclining motor (front seatback frame sub-assembly LH).

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

NG

REPLACE RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH) 2019 - 2020 MY Avalon Avalon HV [04/2018 - 08/2020]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY 2021 - 2022 MY Avalon Avalon HV [08/2020 -        ]; SEAT: FRONT SEAT ASSEMBLY: DISASSEMBLY

OK

8.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - RECLINING MOTOR (FRONT SEATBACK FRAME SUB-ASSEMBLY LH))

(a) Disconnect the R33 and R30 position control ECU assembly connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R33-10 (RCL+) - a10-3 (RCL+)

Always

Below 1 Ω

R33-10 (RCL+) or a10-3 (RCL+) - Body ground

Always

10 kΩ or higher

R30-6 (RCL-) - a10-1 (RCL-)

Always

Below 1 Ω

R30-6 (RCL-) or a10-1 (RCL-) - Body ground

Always

10 kΩ or higher

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