B1848

DTC Troubleshooting: B1848

DTC B1848:

Headrest Switch Signal Error

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back ON (II).

3. Retract the rear headrests with the headrest switch.

4. Check for DTCs with the HDS.

Is DTC B1848 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections.�

5. Turn the ignition switch to LOCK (0).

6. Disconnect power seat control unit connector A (40P).

7. Disconnect the roof console 28P connector.

8. Check for continuity between body ground and power seat control unit connector A (40P) terminals No. 1 and No. 22 individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 9.

9. Check for continuity between power seat control unit connector A (40P) terminals No. 1 and No. 22.





Is there continuity?

YES -

Repair a short in the wire.�

NO -

Go to step 10.

10. Reconnect the roof console 28P connector.

11. Check for continuity between power seat control unit connector A (40P) terminals No. 1 and No. 22 without pressing the headrest switch.





Is there continuity?

YES -

Faulty headrest switch, replace the roof console Roof Console Replacement.�

NO -

Go to step 12.

12. Disconnect the roof console 28P connector.

13. Check for continuity between roof console 28P connector terminals:

- No. 9 and No. 12
- No. 10 and No. 12





Is there continuity?

YES -

Faulty headrest switch, replace the roof console Roof Console Replacement.�

NO -

Go to the power seat control unit input test Power Rear Headrests (Power Seat Control Unit) Input Test.�