Multiplex Control Unit, Door

DTC Troubleshooting: U1283

DTC U1283:

Door Multiplex Control Unit Lost Communication With Passenger's MICU

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 to ON (II).

3. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U1283 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the door multiplex control unit and the passenger's MICU.

5. From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.

Is the passenger's MICU detected?

YES -

Go to step 10.

NO -

Go to step 6.

6. Measure the voltage between body ground and passenger's under-dash fuse/relay box connector A (38P) terminals No. 14 and No. 35 individually.





Is there battery voltage?

YES -

Go to step 9.

NO -

Go to step 7.

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

8. Check the No. 15 (10 A) fuse in the under-hood fuse/relay box and the No. 5 (7.5 A) fuse in the driver's under-dash fuse/relay box.

Are the fuses OK?

YES -

Repair an open or high resistance in the No. 15 (10 A) and/or No. 5 (7.5 A) fuse circuit.

NO -

Replace the fuse(s). If the fuse blows again, repair a short to ground on the No. 15 (10 A) and/or No. 5 (7.5 A) fuse circuit.

9. Measure the voltage between body ground and passenger's under-dash fuse/relay box connector A (38P) and E (18P) terminals as shown.













Is there less than 0.2 V?

YES -

Go to step 10.

NO -

Repair an open or high resistance in the ground wire(s) or poor ground (G201) and/or (G505).

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

11. Disconnect passenger's under-dash fuse/relay box connector A (38P).

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

13. Check for continuity between passenger's under-dash fuse/relay box connector A (38P) terminals No. 11 and No. 29 and power window master switch 37P connector terminals No. 35 and No. 33 respectively.





Is there continuity?

YES -

Replace the power window master switch Power Window Master Switch Replacement.

NO -

Repair an open or poor connection in the B-CAN wire(s) between the door multiplex control unit and the passenger's MICU.