Operation CHARM: Car repair manuals for everyone.

DTC B

DTC B1226 or DTC indicator B: A Short 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 B1226 or B indicated?

YES - Go to step 4.

NO - Intermittent failure.

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 30P connector.
7. Check for continuity between body ground and the climate control unit 30P connector No. 8 and No. 22 terminals.






Is there continuity?

YES - Repair short to body ground in the wires between the climate control unit and the in-car temperature sensor.

NO - Go to step 8.

8. Check for continuity between the climate control unit 30P connector No. 8 and No. 22 terminals.






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.