B1226

DTC B1226 or DTC indicator B: A Short in the In-car Temperature Sensor Circuit

1. Clear the DTC by turning the ignition switch OFF, and then ON (II).
2. Operate the climate control system in several modes.
3. Check for DTCs using the self-diagnostic or HDS.

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 climate control unit connector A (20P).




7. Check for continuity between the No. 15 terminal of climate control unit connector A (20P) and body ground.

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 8.




8. Check for continuity between the No. 15 terminal and the No. 5 terminal of climate control unit connector A (20P).

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.