DTC Troubleshooting: B1206 (F+AUTO)

DTC B1206 or DTC indicator F and AUTO:
  Climate Control Unit Lost Communication with Gauge Control Module (TACH) (ECT 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 or climate control unit.

4.Check the DTCs.

Is DTC B1206, or F and AUTO indicated?


YES - Go to 5.


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


5.Select UNIT INFORMATION in the BODY ELECTRICAL menu.

6.Select CONNECTED UNIT in the UNIT INFORMATION menu.

Is gauge control module detected?


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


NO - Go to 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 gauge control module input test.n


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