TR Sensor Open Is Indicated

DTC Troubleshooting: B1225 or TR sensor open is indicated

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

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

4. Check for DTCs.

Is DTC B1225 or TR sensor open 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

Is the in-car temperature sensor OK?
YES - Go to step 7.

NO - Replace the in-car temperature sensor.


7. Disconnect the climate control unit 40P connector.

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

Is there continuity?
YES - Go to step 9.

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






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

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.