Manufacturer Code Charts: 4

HVAC DTC Troubleshooting: 4

DTC indicator 4:

An Open in the Mode Control Motor Circuit

1. Turn the ignition switch to LOCK (0), and then back to ON (II).

2. Do the Self-Diagnostic Function with the HVAC control unit.

3. Check for DTCs.

Is DTC 4 indicated?

YES -

Go to step 4.

NO -

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

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

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

Is the mode control motor OK?

YES -

Go to step 6.

NO -

Replace the mode control motor Mode Control Motor Replacement.

6. Disconnect the mode control motor 7P connector.

7. Disconnect the HVAC control unit 24P connector.

8. Check for continuity between the following terminals of the HVAC control unit 24P connector and the mode control motor 7P connector.









Is there continuity?

YES -

Check for loose wires or poor connections at the HVAC control unit 24P connector, and at the mode control motor 7P connector. If the connections are good, substitute a known-good HVAC control unit, and recheck. If the symptom/indication goes away, replace the original HVAC control unit HVAC Control Unit Removal/Installation.

NO -

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