TR Sensor Short Is Indicated

DTC Troubleshooting: B1226 or TR sensor short is indicated

DTC B1226 or TR sensor short is indicated:A Short 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 the climate control unit. Initial Inspection and Diagnostic Overview

4. Check for DTCs.

Is DTC B1226 or TR sensor short 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 body ground and climate control unit 40P connector terminal No. 15.

Is there continuity?
YES - Repair short to body ground in the wire between the climate control unit and the in-car temperature sensor.

NO - Go to step 9.






9. Check for continuity between climate control unit 40P connector terminals No. 15 and No. 33.

Is there continuity?
YES - Repair short in the wires between the climate control unit and the in-car temperature sensor.

NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.