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.Turn the ignition switch OFF, and then ON (II).

3.Do the self-diagnostic with the HDS or climate control unit.

4.Check for DTCs.

Is DTC B1225 or A indicated?


YES - Go to 5.


NO - Intermittent failure, check for loose wires or poor connections on the in-car temperature sensor circuit.n


5.Turn the ignition switch OFF.

6.Remove the in-car temperature sensor and test it.

Is the in-car temperature sensor OK?


YES - Go to 7.


NO - Replace the  in-car temperature sensor.n


7.Disconnect the climate control unit 32P connector.

8.Check for continuity between the climate control unit 32P connector terminal No. 26 and the in-car temperature sensor 2P connector terminal No. 1.

 

Is there continuity?


YES - Go to 9.


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


9.Check for continuity between the climate control unit 32P connector terminal No. 19 and the 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 32P 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.n


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