HVAC

DTC Troubleshooting: B1228 (5)

DTC B1228 or DTC indicator 5:

A Short in the Outside Air Temperature Sensor Circuit

1. Clear the DTCs with the HDS.

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

3. Do the self-diagnostic function with the HDS or the HVAC control unit.

4. Check for DTCs.

Is DTC B1228 or 5 indicated?

YES -

Go to step 5.

NO -

Intermittent failure.�

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

6. Remove the outside air temperature sensor Service and Repair, and test it Outside Air Temperature Sensor Test.

Is the outside air temperature sensor OK?

YES -

With the outside air temperature sensor disconnected, go to step 7.

NO -

Replace the outside air temperature sensor Service and Repair.�

7. Disconnect HVAC control unit connector A (24P).

8. Check for continuity between HVAC control unit connector A (24P) terminal No. 21 and body ground.





Is there continuity?

YES -

Repair a short to body ground in the wire between the HVAC control unit and the outside air temperature sensor.�

NO -

Go to step 9.

9. Check for continuity between HVAC control unit connector A (24P) terminals No. 4 and No. 21.





Is there continuity?

YES -

Repair a short in the wires between the HVAC control unit and the outside air temperature sensor.�

NO -

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