B and Auto

DTC Troubleshooting: B1226, B and AUTO

DTC B1226 or DTC indicator B and AUTO:

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 function with the HDS How to Troubleshoot the Climate Control Systemor with the climate control unit How to Troubleshoot the Climate Control System.

4. Check for DTCs.

Is DTC B1226 or B and AUTO 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 (With Climate Control).

Is the in-car temperature sensor OK?

YES -

Go to step 7.

NO -

Replace the in-car temperature sensor.�

7. Disconnect climate control unit connectors A (28P) and B (12P).

8. Check for continuity between climate control unit connector A (28P) terminal No. 26 and body ground.





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 9.

9. Check for continuity between climate control unit connector A (28P) terminal No. 26 and climate control unit connector B (12P) terminal No. 10.





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, and recheck. If the symptom/indication goes away, replace the original climate control unit (with navigation) Climate Control Unit Removal/Installation (With Navigation), (without navigation) Climate Control Unit Removal/Installation (Without Navigation).�