DTC U128D: Auto light control unit lost communication with gauge control module
| DTC Description | DTC |
|---|---|
| U128D Auto light control unit lost communication with gauge control module |
DTC (Automatic Lighting Control Unit)
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC ChecksBody Electrical Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode B - Control Unit Not CommunicatingBody Electrical Troubleshooting - B-CAN System Diagnosis Test Mode C - No DTCs and Output Won't Shut OFFBody Electrical Troubleshooting - B-CAN System Diagnosis Test Mode D - No DTCs and Output Won't Turn ON .
- 1. Problem verification:
1. Clear the DTCs with the HDS.
2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
3. Wait for at least 6 seconds.
4. Check for DTCs with the HDS.
DTC Description DTC U128D Auto light control unit lost communication with gauge control module Is DTC U128D indicated?
YES
Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for loose or poor connections.
- 2. Determine possible failure area (gauge control module power and ground, B-CAN lines):
1. Select GAUGES from the BODY ELECTRICAL SYSTEM SELECT menu, and then select DATA LIST.
Does the Data List appear?
YES
Go to step 5.
NO
Go to step 3.
- 3. Fuse check:
1. Turn the vehicle to the OFF (LOCK) mode.
2. Check the following fuse.
Fuse No. A29 (10 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
Go to step 4.
NO
Replace the fuse. If the fuse blows again, repair a short to ground in the No. A29 (10 A) fuse circuit.
- 4. Open wire check (+B BACK UP line):
1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connector.
Gauge control module connector A (32P) 3. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Gauge control module connector A (32P): disconnected
Test point 1 Gauge control module connector A (32P) No. 1 Test point 2 Body ground Is there battery voltage?
YES
The +B BACK UP wire is OK. Check for an open in the wire(s) between the gauge control module and body ground. If the wire(s) is OK, check for poor ground at G502.
NO
Repair an open or high resistance in the wire.
- 5. Open wire check (B-CAN_H line):
1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connectors.
Automatic lighting control unit/sensor 7P connector Gauge control module connector A (32P)
3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Automatic lighting control unit/sensor 7P connector: disconnected
Gauge control module connector A (32P): disconnected
Test point 1 Automatic lighting control unit/sensor 7P connector No. 6 Test point 2 Gauge control module connector A (32P) No. 30 Is there continuity?
YES
The B-CAN_H wire is OK. Go to step 6.
NO
Repair an open in the wire between the automatic lighting control unit/sensor and the gauge control module.
- 6. Open wire check (B-CAN_L line):
1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) Gauge control module connector A (32P): disconnected
Automatic lighting control unit/sensor 7P connector: disconnected
Test point 1 Automatic lighting control unit/sensor 7P connector No. 7 Test point 2 Gauge control module connector A (32P) No. 31 Is there continuity?
YES
The B-CAN_L wire is OK. Replace the gauge control module .
NO
Repair an open in the wire between the automatic lighting control unit/sensor and the gauge control module.