Climate Control Unit

DTC Troubleshooting: U128D

DTC U128D:

Climate Control Unit Lost Communication with Gauge Control Module

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. Do the self-diagnostic function with the HDS.

4. Check for DTCs.

Is DTC U128D indicated?

YES -

Go to step 5.

NO -

The system is OK at this time. Check for loose wires or poor connections on the gauge control module and climate control unit circuit.

5. Select B-CAN Control Units Information in the BODY ELECTRICAL menu.

6. Select Check Connected Control Units in the B-CAN Control Units Information menu.

Is the gauge control module detected?

YES -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.

NO -

Go to step 7.

7. Disconnect the gauge control module 32P connector.

8. Disconnect climate control unit connector A (36P).

9. Check for continuity between the following terminals of the gauge control module 32P connector and climate control unit connector A (36P).









Is there continuity?

YES -

Go to gauge control module input test Component Tests and General Diagnostics.

NO -

Repair an open in the wire between the climate control unit and the gauge control module.