Manufacturer Code Charts: 3

Control System DTCs

HVAC DTC Troubleshooting: 3

DTC indicator 3 : A Problem in the Air Mix Control Motor Circuit, Linkage, Door, or Motor

1. Problem verification:

-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 How To Troubleshoot The Heating and A/C Systems.

-3. Check for DTCs.

Is DTC 3 indicated?
-YES- Go to step 2.
-NO- Intermittent failure. Check for loose wires or poor connections in the air mix control motor circuit.

2. Open wire check (M-HOT DR/M-HOT, M-COOL DR/M-COOL lines):

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connectors.






-3. Check for continuity between test points 1 and 2 respectively.














Is there continuity?
-YES- The M-HOT DR/M-HOT and M-COOL DR/M-COOL wires are not open. Go to step 3.
-NO- Repair an open in the wire(s) between the HVAC control unit and the air mix control motor.

3. Shorted wire check (M-HOT DR/M-HOT, M-COOL DR/M-COOL lines):

-1. Check for continuity between test points 1 and 2 individually.














Is there continuity?
-YES- Repair a short to body ground in the wire(s) between the HVAC control unit and the air mix control motor.
-NO- The M-HOT DR and M-COOL DR wires are OK. Go to step 4.

4. Air mix control motor check:

-1. Test the air mix control motor Air Mix Control Motor Test (Manual A/C).

Is the air mix control motor OK?
-YES- Replace the HVAC control unit HVAC Control Unit Removal And Installation.
-NO- Replace the air mix control motor Air Mix Control Motor Removal And Installation (Manual A/C), or repair the air mix control linkage or door.