B1225

DTC B1225 or TR sensor open is indicated.:
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 self-diagnostic.

Is DTC B1225 or TR sensor open 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 OFF.
5. Remove the in-car temperature sensor and test it.

Is the in-car temperature sensor OK?

YES - Go to step 6.

NO - Replace the in-car temperature sensor.

6. Disconnect the climate control unit 40P connector.




7. Check for continuity between the No. 15 terminal of the climate control unit 40P connector and the No. 3 terminal of the in-car temperature sensor 4P connector.

Is there continuity?

YES - Go to step 8.

NO - Repair open in the wire between the climate control unit and the in-car temperature sensor.




8. Check for continuity between the No. 33 terminal of the climate control unit 40P connector and the No. 2 terminal of the in-car temperature sensor 4P connector.

Is there continuity?

YES - Check for loose wires or poor connections at the climate control unit 40P connector and at the in-car temperature sensor 4P 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.

NO - Repair open in the wire between the climate control unit and the in-car temperature sensor.