B2656
SEAT: REAR POWER SEAT CONTROL SYSTEM: B2656: Upper Lumbar Adjustment Sensor Malfunction
B2656 - Upper Lumbar Adjustment Sensor Malfunction
DESCRIPTION
When the position control ECU does not receive a sensor signal despite forward or backward movement of the seat by power seat motor operation, this DTC is output.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK FOR DTC
(a) DTC output area check
(1) Using the Techstream, determine the area that output the DTC.
Result:
B -- PERFORM ACTIVE TEST USING TECHSTREAM (POWER SEAT MOTOR FUNCTION)
A -- Continue to next step.
2. 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.
Rear Left Seat
OK:
Motor operates normally.
NG -- INSPECT REAR SEATBACK ASSEMBLY LH (POWER SEAT MOTOR)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU LH - REAR POWER SEAT MOTOR LH AND BODY GROUND)
(a) Disconnect the f43 ECU connector.
(b) Disconnect the f45 motor connector.
(c) Measure the resistance according to the values in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK REAR SEATBACK ASSEMBLY LH (POSITION CONTROL SENSOR)
(a) Disconnect the f45 motor connector.
(b) Measure the voltage according to the values in the table below.
Standard voltage:
Result
C -- REPLACE POSITION CONTROL ECU LH Disassembly
B -- REPLACE POSITION CONTROL ECU LH Disassembly
A -- Continue to next step.
5. CHECK REAR SEATBACK ASSEMBLY LH (POSITION CONTROL SENSOR)
(a) Reconnect the f45 motor connector.
(b) Measure the voltage according to the values in the table below.
Standard voltage:
Result
C -- REPLACE REAR SEATBACK ASSEMBLY LH Disassembly
B -- REPLACE REAR SEATBACK ASSEMBLY LH Disassembly
A -- Continue to next step.
6. CHECK FOR DTC
(a) Clear the DTC Rear Power Seat Control System.
(b) Recheck for DTC.
OK:
DTC B2656 is not output.
Result
C -- REPLACE POSITION CONTROL ECU LH Disassembly
B -- REPLACE POSITION CONTROL ECU LH Disassembly
A -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting
7. INSPECT REAR SEATBACK ASSEMBLY LH (POWER SEAT MOTOR)
(a) Check operation of the power seat motor (upper lumbar motor).
(1) Check if the seatback moves smoothly when the battery is connected to the upper lumbar motor connector terminals.
OK:
Result
C -- REPLACE REAR SEATBACK ASSEMBLY LH Disassembly
B -- REPLACE REAR SEATBACK ASSEMBLY LH Disassembly
A -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU LH - REAR POWER SEAT MOTOR LH)
(a) Disconnect the f24 ECU connector.
(b) Disconnect the f45 motor connector.
(c) Measure the resistance according to the values in the table below.
Standard resistance:
Result
C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPLACE POSITION CONTROL ECU LH Disassembly
A -- REPLACE POSITION CONTROL ECU LH Disassembly
9. 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.
Rear Right Seat
OK:
Motor operates normally.
NG -- INSPECT REAR SEATBACK ASSEMBLY RH (POWER SEAT MOTOR)
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU RH - REAR POWER SEAT MOTOR RH AND BODY GROUND)
(a) Disconnect the f39 ECU connector.
(b) Disconnect the f40 motor connector.
(c) Measure the resistance according to the values in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
11. CHECK REAR SEATBACK ASSEMBLY RH (POSITION CONTROL SENSOR)
(a) Disconnect the f40 motor connector.
(b) Measure the voltage according to the values in the table below.
Standard voltage:
Result
C -- REPLACE POSITION CONTROL ECU RH Disassembly
B -- REPLACE POSITION CONTROL ECU RH Disassembly
A -- Continue to next step.
12. CHECK REAR SEATBACK ASSEMBLY RH (POSITION CONTROL SENSOR)
(a) Reconnect the f40 motor connector.
(b) Measure the voltage according to the value in the table below.
Standard voltage:
Result
C -- REPLACE REAR SEATBACK ASSEMBLY RH Disassembly
B -- REPLACE REAR SEATBACK ASSEMBLY RH Disassembly
A -- Continue to next step.
13. CHECK FOR DTC
(a) Clear the DTC Rear Power Seat Control System.
(b) Recheck for DTC.
OK:
DTC B2656 is not output.
Result
C -- REPLACE POSITION CONTROL ECU RH Disassembly
B -- REPLACE POSITION CONTROL ECU RH Disassembly
A -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting
14. INSPECT REAR SEATBACK ASSEMBLY RH (POWER SEAT MOTOR)
(a) Check operation of the power seat motor (upper lumbar motor).
(1) Check if the seatback moves smoothly when the battery is connected to the upper lumbar motor connector terminals.
OK:
Result
C -- REPLACE REAR SEATBACK ASSEMBLY RH Disassembly
B -- REPLACE REAR SEATBACK ASSEMBLY RH Disassembly
A -- Continue to next step.
15. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU RH - REAR POWER SEAT MOTOR RH)
(a) Disconnect the f4 ECU connector.
(b) Disconnect the f40 motor connector.
(c) Measure the resistance according to the values in the table below.
Standard resistance:
Result
C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPLACE POSITION CONTROL ECU RH Disassembly
A -- REPLACE POSITION CONTROL ECU RH Disassembly