B

DTC Troubleshooting: B1226 or Indicator 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 - 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 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 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 (With Climate Control) and recheck. If the symptom/indication goes away, replace the original climate control unit.