B1225

DTC Troubleshooting: B1225 (A and AUTO)

DTC B1225 or DTC indicator A and AUTO:

An Open in the In-Car Temperature Sensor Circuit

1. Clear the DTC with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Do the self-diagnostic function with the HDS or the climate control unit. Initial Inspection and Diagnostic Overview

4. Check for DTCs.

Is DTC B1225 or A and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.�

5. Turn the ignition switch to LOCK (0).

6. Remove the in-car temperature sensor Service and Repair and test it In-car Temperature Sensor Test (With Climate Control).

Is the in-car temperature sensor OK?

YES -

With the in-car temperature sensor disconnected, go to step 7.

NO -

Replace the in-car temperature sensor Service and Repair.�

7. Disconnect the climate control unit 36P connector.

8. Check for continuity between climate control unit 36P connector terminal No. 11 and in-car temperature sensor 2P connector terminal No. 1.





Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire between the climate control unit and the in-car temperature sensor.�

9. Check for continuity between climate control unit 36P connector terminal No. 22 and in-car temperature sensor 2P connector terminal No. 2.





Is there continuity?

YES -

Check for loose wires or poor connections at the climate control unit 36P connector and at the in-car temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�

NO -

Repair an open in the wire between the climate control unit and the in-car temperature sensor.�