Diagnosis code 31: Air mixing door control motor and potentiometer sensor system
COMMENTS ON TROUBLE SYMPTOM
This code is set when the air mixing door control motor potentiometer does not send any signal to the A/C-ECU due to short or open circuit.POSSIBLE CAUSES
- Malfunction of the air mixing door control motor and potentiometer
- Damaged the wiring harness or connectors
- Malfunction of the automatic air conditioner control panel (A/C-ECU)
DIAGNOSIS
Step 3. Check the wiring harness between C-27 A/C-ECU connector (terminals 10, 5 and 20) and C-313 air mixing door control motor and potentiometer connector (terminals 2, 5 and 20).
NOTE: Prior to the wiring harness inspection, check intermediate connector C-36, mode selection damper control motor and potentiometer connector C-315 and heater water temperature sensor connector C-314, and repair if necessary.
- Check the sensor power supply, sensor earth and signal line for open or short circuit.
Q: Is the check result normal?
YES:
Replace the automatic air conditioner control panel (A/C-ECU)NO: Repair the wiring harness.