Toyota 4Runner: Reclining Sensor Malfunction (B2651)

Toyota 4Runner Service Manual / Vehicle Interior / Seat / Front Power Seat Control System(w/ Memory) / Reclining Sensor Malfunction (B2651)

DESCRIPTION

When the front power seat switch LH does not receive a sensor signal despite forward or backward movement of the seatback by power seat motor operation, this DTC is stored.

DTC Code	DTC Detection Condition	Trouble Area
B2651	The forward and backward lock detection position of the sensor is the same.	Front power seat switch LH Separate type front seatback spring assembly LH (Reclining motor) Harness or connector

WIRING DIAGRAM

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (POWER SEAT MOTOR FUNCTION)

(a) Select the Active Test, use the Techstream to generate a control command, and then check the power seat motor function (See page ).

Driver Seat

Tester Display	Test Part	Control Ranger	Diagnostic Note
Seat Reclining	Seat reclining operation	Front / OFF / Rear	-

OK:

Motor operates normally.

GO TO STEP 5

2.	CHECK FRONT POWER SEAT SWITCH LH (RECLINING MOTOR CIRCUIT)

(a) Disconnect the d5 reclining motor connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
d5-2 (O/P) - d5-3 (GND)	Reclining switch on	4.8 to 5.1 V

Text in Illustration

*a	Front view of wire harness connector (to Separate Type Front Seatback Spring Assembly LH [Reclining Motor])

GO TO STEP 4

3.	CHECK SEPARATE TYPE FRONT SEATBACK SPRING ASSEMBLY LH (RECLINING MOTOR)

(a) Connect the d5 reclining motor connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
d5-2 (O/P) - Body ground	Reclining switch on	4.5 to 4.8 V

Text in Illustration

*a	Component with harness connected (Separate Type Front Seatback Spring Assembly LH [Reclining Motor])

REPLACE FRONT POWER SEAT SWITCH LH

REPLACE SEPARATE TYPE FRONT SEATBACK SPRING ASSEMBLY LH (RECLINING MOTOR)

4.	CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH - RECLINING MOTOR)

(a) Disconnect the b19 front power seat switch LH connector.

(b) Disconnect the d5 reclining motor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
b19-11 (SSRR) - d5-2 (O/P)	Always	Below 1 Ω
b19-1 (SGND) - d5-3 (GND)	Always	Below 1 Ω
b19-11 (SSRR) - Body ground	Always	10 kΩ or higher
b19-1 (SGND) - Body ground	Always	10 kΩ or higher

REPLACE FRONT POWER SEAT SWITCH LH

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT SEPARATE TYPE FRONT SEATBACK SPRING ASSEMBLY LH (RECLINING MOTOR)

(a) Remove the front seatback board sub-assembly (See page ).

(b) Disconnect the b5 reclining motor connector.

OK:

Measurement Condition	Operational Direction
Battery positive (+) → 1 (FWD) Battery negative (-) → 4 (BACK)	Seatback moves forward
Battery positive (+) → 4 (BACK) Battery negative (-) → 1 (FWD)	Seatback moves backward

Measurement Condition

Operational Direction

Battery positive (+) → 1 (FWD)

Battery negative (-) → 4 (BACK)

Seatback moves forward

Battery positive (+) → 4 (BACK)

Battery negative (-) → 1 (FWD)

Seatback moves backward

Text in Illustration

*a	Component without harness connected (Separate Type Front Seatback Spring Assembly LH [Reclining Motor])

REPLACE SEPARATE TYPE FRONT SEATBACK SPRING ASSEMBLY LH (RECLINING MOTOR)

6.	CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH LH - RECLINING MOTOR)

(a) Disconnect the b18 front power seat switch LH connector.

(b) Disconnect the d5 reclining motor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
b18-9 (RCL+) - d5-1 (FWD)	Always	Below 1 Ω
b18-11 (RCL-) - d5-4 (BACK)	Always	Below 1 Ω
b18-9 (RCL+) - Body ground	Always	10 kΩ or higher
b18-11 (RCL-) - Body ground	Always	10 kΩ or higher

REPLACE FRONT POWER SEAT SWITCH LH

REPAIR OR REPLACE HARNESS OR CONNECTOR

Short in Sensor with Motor Power Supply Circuit (B2658)

DESCRIPTION This DTC is stored when a power seat motor operates (a position control sensor is being supplied with power) and the power supply voltage does not rise to the specified value. ...

Front Vertical Sensor Malfunction (B2652)

DESCRIPTION When the front power seat switch LH does not receive a sensor signal despite upward or downward movement of the front of the seat cushion by power seat motor operation, this DTC is st ...

Other materials about Toyota 4Runner:

Airbag Signal Malfunction/Not Input (B15C4)
DESCRIPTION If the DCM (Telematics Transceiver) detects an error in the communication between the DCM (Telematics Transceiver) and center airbag sensor assembly as a result of the DCM (Telematics Transceiver) self check, this DTC will be set. ...

Light Sensor Circuit Malfunction (B1244)
DESCRIPTION The automatic light control sensor detects ambient light, converts it into an electrical signal, and outputs it to the main body ECU. The main body ECU turns on or off the headlights and taillights according to the signal. DTC Code ...