| DTC B1231 or DTC indicator G: | An Open in the Evaporator Temperature Sensor Circuit |
| 1. | Clear the DTC with the HDS. |
| 2. | Turn the ignition switch OFF, and then ON (II). |
| 3. | Do the self-diagnostic with the HDS or climate control unit. |
| 4. | Check for DTCs. Is DTC B1231 or G indicated? YES - Go to 5. NO - Intermittent failure, check for loose wires or poor connections on the evaporator temperature sensor circuit.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Remove the evaporator temperature sensor and test it. Is the evaporator temperature sensor OK? YES - Go to 7. NO - Replace the evaporator temperature sensor.n |
| 7. | Disconnect the climate control unit 32P connector. |
| 8. | Check for continuity between the climate control unit 32P connector terminal No. 8 and the evaporator temperature sensor 2P connector terminal No. 2.
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. | Check for continuity between the climate control unit 32P connector terminal No. 19 and the evaporator temperature sensor 2P connector terminal No. 1.
Is there continuity? YES - Check for loose wires or poor connections at the climate control unit 32P connector 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 NO - Repair open in the wire between the climate control unit and the evaporator temperature sensor.n |