| DTC indicator G or DTC B1231: | An Open in the Evaporator 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 G or B1231 indicated? YES - Go to 5. NO - Intermittent failure, check for loose wires or poor connections on the evaporator temperature sensor circuit.n |
| 5. | Remove the evaporator temperature sensor and test it. Does the evaporator temperature sensor test OK? YES - Go to 6. NO - Replace the evaporator temperature sensor.n |
| 6. | Disconnect climate control unit connector A (22P). |
| 7. | Check for continuity between the No. 14 terminal of climate control unit connector A (22P) and the No. 1 terminal of the evaporator temperature sensor 2P connector. Is there continuity? YES - Go to 8. NO - Repair open in the wire between the climate control unit and the evaporator temperature sensor.n |
| 8. | Check for continuity between the No. 15 terminal of climate control unit connector A (22P) and the No. 2 terminal of the evaporator temperature sensor 2P connector. Is there continuity? YES - Go to 9. NO - Repair open in the wire between the climate control unit and the evaporator temperature sensor.n |
| 9. | Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication varification status. Is the communication OK? YES - Check for loose wire or poor connections at climate control unit connector A (22P) and at the evaporator temperature sensor 2P connector. If the connections are good, 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 - Check for loose wire or poor connections at climate control unit connector A (22P) and at the evaporator temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.n |