Electronic Climate Control

DTC B1207: Climate Control Unit Lost Communication with Gauge Control Module (ILLUMI message)

1. Push the AUTO button.

Does the climate control turn on?

YES - Go to step 2.

NO - Go to climate control unit power and ground circuits troubleshooting.

2. Turn the ignition switch OFF then ON.
3. Turn the climate control system on and operate several functions (A/C ON/OFF, air mix and blend door operations, temperature settings etc.).
4. Check for DTCs using the HDS.

Is DTC indicated?

YES -
- DTC B1205 indicated: go to step 5.
- DTC B1206 or B1207 indicated: go to step 6.

NO - Intermittent failure, the gauge control module and climate control unit are OK at this time.

5. Check for DTCs using the HDS.

Is DTC B1060 indicated?

YES - Perform the gauge control module self test procedure.

NO - The climate control unit is faulty, replace the climate control unit.

6. Disconnect the climate control unit 30P connector.
7. Remove the gauge control module.




8. Check for continuity between the No. 7 terminal of the climate control unit 30P connector and the No. 25 terminal of the gauge control module 3OP connector.

Is there continuity?

YES - Check for loose wire or poor connections at the climate control unit 30P connector and at the gauge control module 3OP connector. If the connections are good, substitute a known-good climate control unit and/or gauge control module, and recheck. If the symptom/indication goes away, replace the original climate control unit and/or gauge control module.

NO - Repair open in the wire between the climate control unit and the gauge control module.