B1226

DTC Troubleshooting: B1226 (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 the self-diagnostic function.

Is DTC B1226 or B indicated?

YES -

Go to step 4.

NO -

Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.�

4. Turn the ignition switch to LOCK (0).

5. Remove the in-car temperature sensor Service and Repair, and test it In-Car Temperature Sensor Test (With Climate Control).

Is the in-car temperature sensor OK?

YES -

With the in-car temperature sensor disconnected, go to step 6.

NO -

Replace the in-car temperature sensor Service and Repair.�

6. Disconnect the climate control unit 30P connector.

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





Is there continuity?

YES -

Repair a 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 climate control unit 30P connector terminals No. 8 and No. 22.





Is there continuity?

YES -

Repair a short in the wires between the climate control unit and the in-car temperature sensor.�

NO -

Substitute a known-good climate control unit Climate Control Unit Removal/Installation, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�