Audio Unit
DTC Troubleshooting: U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280
DTC U1280:
Communication Bus Line Error (BUS-OFF)
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 U1280 indicated?
YES -
Go to step 5.
NO -
Intermittent failure, the system is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition Battery Test and the charging system Symptom Related Diagnostic Procedures.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.
*1: With climate control
*2: Without climate control
*3: With navigation
*4: Without navigation and with USB adapter
*5: With 3 line type
*6: With DPMS
*7: With sliding door
*8: With parking and back-up system
*9: With power tailgate
*10: With HID
*11: With seat heater
*12: With BSI
Is DTC U1280 indicated with each individual unit disconnected?
YES -
Leave the connectors disconnected, and go to step 7.
NO -
Go to the input test for the control unit that was disconnected when DTC U1280 did not reset, and perform all power and ground input tests. If the tests prove OK, replace that unit.
- Rear MICU input test.
- Door multiplex control unit (power window master switch) input test.
- Gauge control module input test.
- Immobilizer-keyless control unit input test.
- Climate control unit power and ground circuit troubleshooting Climate Control Unit Power And Ground Circuit Troubleshooting (With Climate Control).
- HVAC control unit power and ground circuit troubleshooting HVAC Control Power And Ground Circuit Troubleshooting (Without Climate Control).
- Power seat control unit input test Testing and Inspection.
- Navigation unit input test Navigation System Description.
- Audio unit input test Description and Operation.
- Left power sliding door control unit input test Power Sliding Door Control Unit Input Test.
- Right power sliding door control unit input test Power Sliding Door Control Unit Input Test.
- Power tailgate control unit input test Component Tests and General Diagnostics.
- Parking and back-up sensor control unit input test Service and Repair.
- Seat heater control unit input test Service and Repair.
- BSI control unit input test Blind Spot Information System Description.
7. Turn the ignition switch to LOCK (0).
8. Remove the driver's kick panel Service and Repair.
9. Disconnect these items:
- Driver's under-dash fuse/relay box connector E (44P)
- Driver's under-dash fuse/relay box connector G (16P)
- Driver's under-dash fuse/relay box connector H (13P)
10. Check for continuity between driver's under-dash fuse/relay box connector E (44P) terminals No. 31, No. 32, then between terminals No. 43, and No. 44 respectively.
Is there continuity?
YES -
Repair a short in the B-CAN wires.
NO -
Go to step 11.
11. Check for continuity between driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2.
Is there continuity?
YES -
Repair a short in the B-CAN wires.
NO -
Go to step 12.
12. Check for continuity between driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10.
Is there continuity?
YES -
Repair a short in the B-CAN wires.
NO -
Go to step 13.
13. Check for continuity between body ground and driver's under-dash fuse/relay box connector E (44P) terminals No. 31, No. 32, No. 43, and No. 44 individually.
Is there continuity?
YES -
Repair a short to ground in the B-CAN wire(s).
NO -
Go to step 14.
14. Check for continuity between body ground and driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2 individually.
Is there continuity?
YES -
Repair a short to ground in the B-CAN wire(s).
NO -
Go to step 15.
15. Check for continuity between body ground and driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10 individually.
Is there continuity?
YES -
Repair a short to ground in the B-CAN wire(s).
NO -
Go to step 16.
16. Turn the ignition switch to ON (II).
17. Measure the voltage between body ground and driver's under-dash fuse/relay box connector E (44P) terminals No. 31, No. 32, No. 43, and No. 44 individually.
Is there voltage?
YES -
Repair a short to power in the B-CAN wire(s).
NO -
Go to step 18.
18. Measure the voltage between body ground and driver's under-dash fuse/relay box connector G (16P) terminals No. 1 and No. 2 individually.
Is there voltage?
YES -
Repair a short to power in the B-CAN wire(s).
NO -
Go to step 19.
19. Measure the voltage between body ground and driver's under-dash fuse/relay box connector H (13P) terminals No. 5 and No. 10 individually.
Is there voltage?
YES -
Repair a short to power in the B-CAN wire(s).
NO -
Faulty MICU; replace the driver's under-dash fuse/relay box, USA models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal And Installation (USA Model), Canada models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal And Installation (Canada Model).