B1239
DTC B1239 or DTC indicator A: An Open or Short in the Mode Control Motor Circuit1. 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 for DTCs.
Is DTC B1239 or A 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 OFF.
6. Test the mode control motor.
Is the mode control motor OK?
YES - Go to step 7.
NO - Replace the mode control motor.
7. Disconnect the mode control motor 7P connector.
8. Disconnect climate control unit connector A (24P).
9. Check for continuity between the terminals of climate control unit connector A (24P) and the mode control motor 7P connector.
Is there continuity?
YES - Go to step 10.
NO - Repair open in the wire(s) between the climate control unit and the mode control motor.
10. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 1, 2, 3 and 4 individually.
Is there continuity?
YES - Repair short to body ground in the wire(s) between the climate control unit and the mode control motor.
NO - Go to step 11.
11. Check for continuity between the terminals of climate control unit connector A (24P) as shown.
Is there continuity between any of the terminals?
YES - Repair short in the wire(s) between climate control unit and mode control motor.
NO - Go to step 12.
12. Turn the ignition switch ON (II), and check the same terminals for voltage.
Is there any voltage?
YES - Repair short to power in the wire(s) between the climate control unit and the mode control motor.
NO - Check for loose wire or poor connections at climate control unit connector A (24P) 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.