REAR POWER SEAT CONTROL SYSTEM, Diagnostic DTC:B2657

DTC Code	DTC Name
B2657	Ottoman Sensor Malfunction

DESCRIPTION

When the position control ECU does not receive a sensor signal despite upward or downward movement of the seat by power seat motor operation, this DTC is output.

DTC Code	DTC Detection Condition	Trouble Area
B2657	Sensor's upward and downward lock detection position is the same	Position control ECU Rear No. 1 seat adjuster assembly Rear No. 2 seat adjuster assembly Harness or connector

WIRING DIAGRAM

PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (POWER SEAT MOTOR FUNCTION)

Select the Active Test, use the intelligent tester to generate a control command, and then check the power seat motor function.

Rear Right Seat (for LHD)
Tester Display	Test Part	Control Range	Diagnostic Note
Ottoman	Seat ottoman operation	Up / OFF / Down	-

Rear Left Seat (for RHD)
Tester Display	Test Part	Control Range	Diagnostic Note
Ottoman	Seat ottoman operation	Up / OFF / Down	-

OK
Motor operates normally.

INSPECT REAR SEAT ADJUSTER ASSEMBLY (POWER SEAT MOTOR) Click here

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU - REAR POWER SEAT MOTOR)

for LHD:
1. Disconnect the f39 ECU connector.
2. Disconnect the f16 motor connector.
for RHD:
1. Disconnect the f43 ECU connector.
2. Disconnect the f33 motor connector.

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

Standard resistance

for LHD
Tester Connection	Condition	Specified Condition
f39-17 (PVCC) - f16-4 (PVCC)	Always	Below 1 Ω
f39-9 (SSRO) - f16-2 (SSRO)	Always	Below 1 Ω
f39-23 (SGND) - f16-3 (GND)	Always	Below 1 Ω
f39-17 (PVCC) - Body ground	Always	10 kΩ or higher
f39-9 (SSRO) - Body ground	Always	10 kΩ or higher
f39-23 (SGND) - Body ground	Always	10 kΩ or higher

for RHD
Tester Connection	Condition	Specified Condition
f43-17 (PVCC) - f33-4 (PVCC)	Always	Below 1 Ω
f43-9 (SSRO) - f33-2 (SSRO)	Always	Below 1 Ω
f43-23 (SGND) - f33-3 (GND)	Always	Below 1 Ω
f43-17 (PVCC) - Body ground	Always	10 kΩ or higher
f43-9 (SSRO) - Body ground	Always	10 kΩ or higher
f43-23 (SGND) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK REAR SEAT ADJUSTER ASSEMBLY (POSITION CONTROL SENSOR)

for LHD:

Disconnect the f16 motor connector.
for RHD:

Disconnect the f33 motor connector.

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

Standard voltage

for LHD
Tester Connection	Switch Condition	Specified Condition
f16-4 (PVCC) - f16-3 (GND)	Ottoman switch ON	7.2 to 8.8 V

for RHD
Tester Connection	Switch Condition	Specified Condition
f33-4 (PVCC) - f33-3 (GND)	Ottoman switch ON	7.2 to 8.8 V

REPLACE POSITION CONTROL ECU Click here

CHECK REAR SEAT ADJUSTER ASSEMBLY (POSITION CONTROL SENSOR)

for LHD:

Reconnect the f16 motor connector.
for RHD:

Reconnect the f33 motor connector.

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

Standard voltage

for LHD
Tester Connection	Switch Condition	Specified Condition
f16-2 (SSRO) - Body ground	Ottoman switch ON	0 to 8 V

for RHD
Tester Connection	Switch Condition	Specified Condition
f33-2 (SSRO) - Body ground	Ottoman switch ON	0 to 8 V

REPLACE REAR SEAT ADJUSTER ASSEMBLY Click here

CHECK FOR DTC
1. Clear the DTC Click here.
2. Recheck for DTC.
  
  OK
  
  DTC B2657 is not output.
OK
USE SIMULATION METHOD TO CHECK Click here

NG
REPLACE POSITION CONTROL ECU Click here

OK
DTC B2657 is not output.

INSPECT REAR SEAT ADJUSTER ASSEMBLY (POWER SEAT MOTOR)


*1	Component without harness connected: (Rear Pwer Seat Motor)

Check operation of the power seat motor (ottoman motor).

Check if the seat adjuster moves smoothly when the battery is connected to the ottoman motor connector terminals.

Measurement Condition

Operational Direction

Battery positive (+) → 5

Battery negative (-) → 1

Upward

Battery positive (+) → 1

Battery negative (-) → 5

Downward