B1226

DTC Troubleshooting: B1226 (B)

DTC B1226 or DTC indicator B :

A Short in the In-car Temperature Sensor Circuit

NOTE:If DTC B1226 is detected with HDS, it is not necessary to do step 1.

1. Check the sensor input display mode, and select "in-car temperature sensor" according to the table Initial Inspection and Diagnostic Overview.

NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause.

Is sensor value indicated "Er"?

YES -

Go to step 2

NO -

Go to troubleshooting DTC B1240 or DTC indicator B B1240

2. Clear the DTC with the HDS.

3. Turn the ignition switch to LOCK (0), and then back to ON (II).

4. Do the self-diagnostic with the HDS Initial Inspection and Diagnostic Overview or the climate control unit Initial Inspection and Diagnostic Overview.

5. Check for DTCs.

Is DTC B1226 or B indicated?

YES -

Go to step 6.

NO -

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

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

7. Remove the in-car temperature sensor Service and Repair, and test it In-Car Temperature Sensor Test.

Is the in-car temperature sensor OK?

YES -

Go to step 8.

NO -

Replace the in-car temperature sensor.�

8. Disconnect climate control unit connector B (16P).

9. Check for continuity between body ground and climate control unit connector B (16P) terminal No. 14.





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 10.

10. Check for continuity between climate control unit connector B (16P) terminals No. 4 and No. 14.





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 Climate Control Unit Removal/Installation.�