Code No. B1051,B1052: Potentiometer system for rear air mix damper <vehicles with dual automatic A/C>














COMMENTS ON TROUBLE SYMPTOM
This code is set when the rear air mixing damper control motor potentiometer does not send any signal to the A/C-ECU due to short or open circuit.

PROBABLE CAUSES

  • Malfunction of the rear air mixing damper control motor and potentiometer
  • Damaged the wiring harness or connectors
  • Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: D-07 A/C-ECU connector and E-134-1 rear air mixing damper control motor and potentiometer connector

Q. Is the check result normal?
Go to Step 2.
Repair the connector.

STEP 2. Check the wiring harness between D-07 A/C-ECU connector (terminals 43, 42 and 41) and E-134-1 rear air mixing damper control motor and potentiometer connector (terminals 7, 3 and 5).
note Prior to the wiring harness inspection, check intermediate connector E-132, D-219 and rear heater unit connector E-134, and repair if necessary.

  • Check the potentiometer power supply, earth and signal line for open or short circuit.

Q. Is the check result normal?
Go to Step 3.
Repair the wiring harness.

STEP 3. Check the rear air mixing damper control motor and potentiometer.
Refer to .

Q. Is the check result normal?
Go to Step 4.
Replace the rear air mixing damper control motor and potentiometer.

STEP 4. M.U.T.-III diagnosis code

Q. Is the diagnosis code set?
Replace the A/C-ECU.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).