B1142

DTC Troubleshooting: B1142

DTC B1142:

Door Multiplex Control Unit Lost Communication With Front Passenger's Power Window Switch (UART Line Open)

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.
- Before troubleshooting, check the No. 12 (7.5 A), No. 16 (7.5 A) and No. 24 (20 A) fuses in the driver's under-dash fuse/relay box

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.

3. Open and close all power windows by using the power window master switch.

4. Check for DTCs with the HDS.

Is DTC B1142 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), or press the engine start/stop button to select the OFF mode.

6. Disconnect the power window master switch 37P connector.

7. Disconnect the panoramic glass roof control unit 10P connector.

8. Check for continuity between power window master switch 37P connector terminal No. 27 and panoramic glass roof control unit 10P connector terminal No. 7.





Is there continuity?

YES -

Go to step 9.

NO -

Repair an open or high resistance in the wire.�

9. Disconnect the front passenger's power window switch 37P connector.

10. Check for continuity between power window master switch 37P connector terminal No. 27 and front passenger's power window switch 37P connector terminal No. 29.





Is there continuity?

YES -

Go to step 11.

NO -

Repair an open or high resistance in the wire.�

11. Check for continuity between power window master switch 37P connector terminal No. 27 and body ground.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 12.

12. Reconnect the power window master switch 37P connector.

13. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

14. Measure the voltage between power window master switch 37P connector terminal No. 27 and body ground.





Is there less than 0.2 V?

YES -

Substitute a known-good power window master switch, then reset the power window control unit and recheck. If the DTC goes away, replace the original power window master switch Power Window Master Switch Replacement. If the DTC is still present, substitute a known-good passenger's power window switch, and recheck. If the DTC is still present, replace the panoramic glass roof control unit Panoramic Glass Roof Motor Replacement.�

NO -

Repair a short to power in the wire.�