DTC U128D: Lost Communication with Gauge Control Module (Climate Control Unit), DTC Indicator 81: Climate Control Unit Lost Communication with Gauge Control Module (ECT message), DTC Indicator 82: Climate Control Unit Lost Communication with Gauge Control Module (ILLUMI message), DTC Indicator 83: Climate Control Unit Lost Communication with Gauge Control Module (VSP message)
- 1. Problem verification:
- 1. Clear the DTCs with the HDS.
- 2. Turn the ignition switch to LOCK (0) and then back to ON (II).
- 3. Do the self-diagnostic with the HDS or the climate control unit - Refer to: How to Troubleshoot the Climate Control System ('12) , How to Troubleshoot the Body Electrical ('12) , How to Troubleshoot the Body Electrical (Gasoline) ('13) , How to Troubleshoot the Climate Control System ('13-'15) , How to Troubleshoot the Body Electrical ('14-'15) .
- 4. Check for DTCs.
Is DTC U128D and 81 and 82 and 83 indicated?
YES
Go to step2.
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 B-CAN CONTROL UNITS INFORMATION from the BODY ELECTRICAL SYSTEM SELECT menu, and then select CHECK CONNECTED CONTROL UNITS.
- 2. Check the DETECT/NOT AVAILABLE information of the GAUGE CONTROL MODULE.
Is DETECT indicated?
YES
Go to step 3.
NO
Go to step 4.
- 3. Open wire check (B_CAN-H, B_CAN-L lines):
- 1. Turn the ignition switch to LOCK (0).
- 2. Disconnect the following connectors.
Gauge control module (tach) 32P connector Climate control unit 32P connector - 3. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0) Gauge control module (tach) 32P connector: disconnected Climate control unit 32P connector: disconnected Test circuit B_CAN-H Test point 1 Gauge control module (tach) 32P connector No. 30 (PNK) Test point 2 Climate control unit 32P connector No. 26 (PNK) Is there continuity?
YES
An open or poor connection in the B_CAN-L wire between the climate control unit and the gauge control module (tach).
NO
An open or poor connection in the B_CAN-H wire between the climate control unit and the gauge control module (tach).
- 4. Fuse check:
- 1. Check the following fuse.
Fuse No. A29 (10 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
The +B_BACK_UP wire is OK. Go to step 5.
NO
Replace the fuse. If the fuse blows again, repair a short to ground in the No. A29 (10 A) fuse circuit.
- 5. Open wire check (+B_BACK_UP line):
- 1. Turn the ignition switch to LOCK (0).
- 2. Disconnect the following connector.
Gauge control module (tach) 32P connector - 3. Measure the voltage between test points 1 and 2.
Test condition IG LOCK (0) Gauge control module (tach) 32P connector: disconnected Test circuit +B_BACK_UP Test point 1 Gauge control module (tach) 32P connector No. 1 (WHT) Test point 2 Body ground Is there battery voltage?
YES
The +B_BACK_UP wire is OK. Go to step 6.
NO
Repair an open or high Ω in the wire.
- 6. Open wire check (GND lines):
- 1. Check for continuity between test points 1 and 2 individually.
Test condition IG LOCK (0) Gauge control module (tach) 32P connector: disconnected Test circuit GND Test point 1 Gauge control module (tach) 32P connector No. 4 (BLK) Test point 2 Body ground Test circuit GND Test point 1 Gauge control module (tach) 32P connector No. 32 (BRN) Test point 2 Body ground Is there continuity?
YES
The GND wires are OK. Go to step 7.
NO
Repair an open or high Ω in the ground wire or poor ground (G502/G503).
- 7. Open wire check (B_CAN-H, B_CAN-L lines):
- 1. Disconnect the following connector.
Climate control unit 32P connector - 2. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0) Gauge control module (tach) 32P connector: disconnected Climate control unit 32P connector: disconnected Test circuit B_CAN-H Test point 1 Gauge control module (tach) 32P connector No. 30 (PNK) Test point 2 Climate control unit 32P connector No. 26 (PNK) Is there continuity?
YES
An open or poor connection in the B_CAN-L wire between the climate control unit and the gauge control module (tach).
NO
An open or poor connection in the B_CAN-H wire between the climate control unit and the gauge control module (tach).