Code No.B1031: Fin thermo Sensor system (short circuit)
Code No.B1032: Fin thermo Sensor system (open circuit)


COMMENTS ON TROUBLE SYMPTOM
This code is set when the fin thermo sensor circuit is short (Code No.B1031) or is open (Code No.B1032).

PROBABLE CAUSES

  • Malfunction of the fin thermo sensor
  • Damaged wiring harness or connectors
  • Malfunction of the heater controller assembly (A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Check that the following service data display contents are normal. (Refer to ).
Item No.20: Air thermo sensor

Q. Is the check result normal?
Go to Step 4.
Go to Step 2.

STEP 2. Check of open and short circuit in + and - line between fin thermo sensor and auto heater controller assembly (A/C-ECU) connector.

Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. Check the fin thermo sensor.

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

STEP 4. Check whether the diagnosis code is reset.

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