Keyless Access Control Unit

DTC Troubleshooting: U1283

DTC U1283:

Keyless Access 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. Press the engine start/stop button to select the OFF, ACC, and ON mode.

3. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U01283 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the keyless access 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 9.

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 8.

NO -

Go to step 7.

7. Check the No. 15 (10 A) fuse in the under-hood fuse/relay box and the No. 12 (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. 12 (7.5 A) fuse circuit.

NO -

Replace the fuse(s). If the fuse blows again, repair a short to ground in the No. 15 (10 A) and/or No. 12 (7.5 A) fuse circuit.

8. 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 9.

NO -

Repair an open or high resistance in the ground wire or poor ground (G203), (G401) and/or (G405).

9. Press the engine start/stop button to select the OFF mode.

10. Disconnect keyless access control unit connector B (32P).

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

12. Check for continuity between passenger's under-dash fuse/relay box connector A (38P) terminals No. 11 and No. 29 and keyless access control unit connector B (32P) terminals No. 8 and No. 7 respectively.





Is there continuity?

YES -

Replace the keyless access control unit.

NO -

An open or poor connection in the B-CAN wire between the keyless access control unit and the passenger's MICU.