B2656
SEAT: REAR POWER SEAT CONTROL SYSTEM: B2656: Upper Lumbar Adjustment Sensor Malfunction
DTC 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 intelligent tester, determine the area that output the DTC.
Result
B -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (POWER SEAT MOTOR FUNCTION)
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (POWER SEAT MOTOR FUNCTION)
(a) Select the ACTIVE TEST, use the intelligent tester or Techstream to generate a control command, and then check the power seat motor function.
(1) Intelligent tester
RL-SEAT
(2) Techstream
Rear Left Seat
OK:
Motor operates normally.
NG -- CHECK REAR SEATBACK ASSEMBLY LH (POWER SEAT MOTOR)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU LH - REAR POWER SEAT POSITION SENSOR LH)
(a) Disconnect the f25 ECU connector.
(b) Disconnect the f30 sensor connector.
(c) Measure the resistance according to the value(s) 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 f30 sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE POSITION CONTROL ECU LH
OK -- Continue to next step.
5. CHECK REAR SEATBACK ASSEMBLY LH (POSITION CONTROL SENSOR)
(a) Reconnect the f30 sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE REAR SEATBACK ASSEMBLY LH
OK -- Continue to next step.
6. CHECK FOR DTC
(a) Recheck for the DTC Rear Power Seat Control System.
OK:
DTC B2656 is not output.
NG -- REPLACE POSITION CONTROL ECU LH
OK -- USE SIMULATION METHOD TO CHECK
7. CHECK 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:
NG -- REPLACE REAR SEATBACK ASSEMBLY LH
OK -- 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 f29 motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE POSITION CONTROL ECU LH
9. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (POWER SEAT MOTOR FUNCTION)
(a) Select the ACTIVE TEST, use the intelligent tester or Techstream to generate a control command, and then check the power seat motor function.
(1) Intelligent tester
RR-SEAT
(2) Techstream
Rear Right Seat
OK:
Motor operates normally.
NG -- CHECK REAR SEATBACK ASSEMBLY RH (POWER SEAT MOTOR)
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU RH - REAR POWER SEAT POSITION SENSOR RH)
(a) Disconnect the f5 ECU connector.
(b) Disconnect the f10 sensor connector.
(c) Measure the resistance according to the value(s) 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 f10 sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
Result
C -- REPLACE POSITION CONTROL ECU RH
B -- REPLACE POSITION CONTROL ECU RH
A -- Continue to next step.
12. CHECK REAR SEATBACK ASSEMBLY RH (POSITION CONTROL SENSOR)
(a) Reconnect the f10 sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
Result
C -- REPLACE REAR SEATBACK ASSEMBLY RH
B -- REPLACE REAR SEATBACK ASSEMBLY RH
A -- Continue to next step.
13. CHECK FOR DTC
(a) Recheck for the DTC Rear Power Seat Control System.
OK:
DTC B2656 is not output.
Result
C -- REPLACE POSITION CONTROL ECU RH
B -- REPLACE POSITION CONTROL ECU RH
A -- USE SIMULATION METHOD TO CHECK
14. CHECK 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:
C -- REPLACE REAR SEATBACK ASSEMBLY RH
B -- REPLACE REAR SEATBACK ASSEMBLY RH
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 f9 motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
Result
C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPLACE POSITION CONTROL ECU RH
A -- REPLACE POSITION CONTROL ECU RH