G and A/C

DTC Troubleshooting: B121A (G and A/C)

DTC B121A or DTC indicator G and A/C ON:

An Open in the Mode Control Motor Circuit

1. Clear the DTC 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 or the climate control unit.

4. Check for DTCs.

Is DTC B121A or G and A/C ON indicated?

YES -

Go to step 5.

NO -

Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.

5. Turn the ignition switch to LOCK (0).

6. Test the mode control motor Mode Control Motor Test.

Is the mode control motor OK?

YES -

Go to step 7.

NO -

Replace the mode control motor Mode Control Motor Replacement.

7. Disconnect the mode control motor 7P connector.

8. Disconnect climate control unit connectors A (28P) and B (12P).

9. Check for continuity between the following terminals of climate control unit connectors A (28P), B (12P), and the mode control motor 7P connector.

















Is there continuity?

YES -

Check for loose wires or poor connections at climate control unit connectors A (28P), B (12P), and at the mode control motor 7P connector. If the connections are good, 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 -

Repair an open in the wire(s) between the climate control unit and the mode control motor.