Manufacturer Code Charts: 10

DTC Troubleshooting: B1228 or Indicator 10

DTC B1228 or DTC indicator 10: A Short in the Outside Air Temperature Sensor Circuit

1. Clear the DTC with the HDS.

2. Operate the heater-A/C control system in several modes.

3. Check for DTCs using the HDS or the self-diagnostic function.

Is DTC B1228 or 10 indicated?
YES - Go to step 4.

NO - Intermittent failure. Check for loose wires or poor connections on the outside air temperature sensor circuit.


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

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

Is the outside air temperature sensor OK?
YES - Go to step 6.

NO - Replace the outside air temperature sensor.


6. Disconnect the HVAC control unit 30P connector.

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

Is there continuity?
YES - Repair short to body ground in the wire between the HVAC control unit and the outside air temperature sensor.

NO - Go to step 8.






8. Check for continuity between the HVAC control unit 30P connector terminals No. 8 and No. 20.

Is there continuity?
YES - Repair short in the wires between the HVAC control unit and the outside air temperature sensor.

NO - Substitute a known-good HVAC control unit, HVAC Control Unit Removal/Installation (Without Climate Control) and recheck. If the symptom/indication goes away, replace the original HVAC control unit.