Code No. B1021,B1022: Air thermo sensor system

COMMENTS ON TROUBLE SYMPTOM

This code is set when the air thermo sensor circuit is short (Code No.B1021) or is open (Code No.B1022).

PROBABLE CAUSES

Malfunction of the air thermo sensor
Damaged the wiring harness or connectors
Malfunction of the automatic A/C control panel (A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Connector check: D-08 A/C-ECU connector and D-129 air thermo sensor connector

Q. Is the check result normal?

	Go to Step 2.

	Repair the connector.

STEP 2. Check the wiring harness between D-08 A/C-ECU connector (terminals 8 and 27) and D-129 air thermo sensor connector (terminals 2 and 1).

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

Q. Is the check result normal?

	Go to Step 3.

	Repair the wiring harness.

STEP 3. Check the air thermo sensor.

Refer to

.

Q. Is the check result normal?

	Go to Step 4.

	Replace the air thermo 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 ).