Operation CHARM: Car repair manuals for everyone.

B1225

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 step 5.

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

5. Turn the ignition switch OFF.
6. Remove the humidity/in-car temperature sensor, and test it.

Is the in-car temperature sensor OK?

YES - Go to step 7.

NO - Replace the humidity/in-car temperature sensor.

7. Disconnect climate control unit connector A (32P).




8. Check for continuity between climate control unit connector A (32P) terminal No. 26 and the humidity/in-car temperature sensor 4P connector terminal No. 1.

Is there continuity?

YES - Go to step 9.

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




9. Check for continuity between climate control unit connector A (32P) terminal No. 19 and the humidity/in-car temperature sensor 4P connector terminal No. 2.

Is there continuity?

YES - Check for loose wires or poor connections at climate control unit connector A (32P) and at the humidity/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 humidity/in-car temperature sensor.