DTC Troubleshooting: B1228 (D)

DTC indicator D or DTC 1228:  A Short in the Outside Air Temperature Sensor Circuit


1.Clear the DTC.

2.Turn the ignition switch OFF, and then ON.

3.Operate the climate control system is several modes.

4.Check the DTCs.

Is DTC or B1228 indicated?


YES - Go to 5.


NO - Intermittent failure.n


5.Remove the outside air temperature sensor.

6.Test the outside air temperature sensor.

Is the resistance within the specifications shown on the graph?


YES - Go to 7.


NO - Replace the  outside air temperature sensor.n


7.Disconnect climate control unit connector A (22P).

8.Check for continuity between the No. 12 terminal of climate control unit connector A (22P) and body ground.

Is there continuity?


YES - Repair short to body ground in the wire between the climate control unit and the outside air temperature sensor.n


NO - Go to 9.

9.Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication verification status.

Is the communication OK?


YES - Substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.n


NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.n