A

DTC Troubleshooting: B1225 (A)

DTC B1225 or DTC indicator A:

An Open in the In-Car Temperature Sensor Circuit

1. Clear the DTC with the HDS.

2. Operate the climate control system in several modes.

3. Check for DTCs using the HDS or the self-diagnostic function.

Is DTC B1225 or A indicated?

YES -

Go to step 4.

NO -

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

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

5. Remove the in-car temperature sensor Service and Repair, and test it.

Is the in-car temperature sensor OK?

YES -

With the in-car temperature sensor disconnected, go to step 6.

NO -

Replace the in-car temperature sensor Service and Repair.

6. Disconnect the climate control unit 30P connector.

7. Check for continuity between climate control unit 30P connector terminal No. 8 and in-car temperature sensor 2P connector terminal No. 1.





Is there continuity?

YES -

Go to step 8.

NO -

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

8. Check for continuity between climate control unit 30P 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 30P connector and the in-car temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit Climate Control Unit Removal/Installation (With Climate Control), and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation (With Climate Control).

NO -

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