Code No. B1011,B1012: Ambient air temperature sensor system


<LHD>

<RHD>









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

PROBABLE CAUSES

  • Malfunction of the ambient air temperature sensor
  • Damaged the wiring harness and connectors
  • Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-32 ambient air temperature sensor connector and D-08 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-32 ambient air temperature sensor connector (terminals 1 and 2) and D-08 A/C-ECU connector (terminals 28 and 8).
note Prior to the wiring harness inspection, check intermediate connector D-241 and joint connector A-16 <RHD>, 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 air temperature sensor.
Refer to .

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

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 ).