Code No. B1011,B1012: Ambient temperature sensor system

COMMENTS ON TROUBLE SYMPTOM
This code is set when the ambient temperature sensor circuit is open (Code No.B1012) or is short (Code No.B1011).

PROBABLE CAUSES

  • Malfunction of the ambient temperature sensor
  • Damaged the wiring harness and connectors
  • Malfunction of the automatic A/C control panel (A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-139 ambient temperature sensor connector and C-44 A/C-ECU connector



Q. Is the check result normal?

Go to Step 2.

Repair the connector.

STEP 2. Check the wiring harness between A-139 ambient temperature sensor connector (terminals 1 and 2) and C-44 A/C-ECU connector (terminals 38 and 31).




note Prior to the wiring harness inspection, check intermediate connector C-33, joint connectors C-137 and C-138, and repair if necessary.

  • Check the sensor signal line and earth line for open and short circuit.

Q. Is the check result normal?

Go to Step 3.

Repair the wiring harness.

STEP 3. Check the ambient temperature sensor.
Refer to .

Q. Is the check result normal?
Go to Step 4.
Replace the ambient temperature sensor.

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

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