B1209

DTC B1209: Climate Control Unit Lost Communication with MICU (MICU/DOOR SW message)

1. Clear the DTC with the HDS.
2. Turn the ignition switch OFF, and then ON (II).
3. Do the self-diagnostic with the HDS.
4. Check the DTCs.

Is DTC B1209 indicated?

YES - Go to step 5.

NO - Intermittent failure, check for loose wires or poor connections on the gauge control module (TACH) and climate control unit circuit.

5. Select UNIT INFORMATION in the BODY ELECTRICAL menu.
6. Select CONNECTED UNIT in the UNIT INFORMATION menu.

Is MICU detected?

YES - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

NO - Go to step 7.

7. Disconnect under-dash fuse/relay box connector Q (16P).
8. Disconnect the gauge control module (TACH) 36P connector.




9. Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 6 and the gauge control module (TACH) 36P connector terminal No. 21.

Is there continuity?

YES - Go to the MICU input test. MICU Input Test

NO - Repair open in the wire between the MICU and the gauge control module (TACH).