DTC C1250: Coupling Air Temperature Sensor Circuit Open: Troubleshooting
C1250: SYMPTOM TROUBLESHOOTING REFERENCE CHART
| Step |
Action |
YES |
NO |
| 1 |
Was "4WD control system check" performed? |
Go to Step 2. |
Go to 4WD CONTROL SYSTEM CHECK . |
| 2 |
Coupling air temperature sensor circuit check
- Disconnect connector from coupling air temperature sensor with ignition switch turned OFF.
- Check for proper connection to "YEL/BLK" and "BLU/WHT" terminals of coupling air temperature sensor connector.
- If connection is OK, measure voltage between "YEL/BLK" terminal of coupling air temperature sensor connector and vehicle body ground with ignition switch turned ON.
Is it 4 - 6 V? |
Go to Step 3. |
Go to Step 5. |
| 3 |
Coupling assembly ground circuit check
- Disconnect connector from 4WD control module with ignition switch turned OFF.
- Measure resistance between "BLU/WHT" terminal of coupling air temperature sensor connector and "G26-24" terminal of 4WD control module connector.
Is resistance below 5 Ω? |
Go to Step 4. |
"BLU/WHT" wire is open or high resistance. |
| 4 |
Coupling air temperature sensor check
- Check coupling air temperature sensor referring to COUPLING AIR TEMPERATURE SENSOR INSPECTION .
Is it in good condition? |
Substitute a known-good 4WD control module and recheck. |
Replace coupling air temperature sensor. |
| 5 |
Coupling assembly circuit check
- Disconnect connector from 4WD control module with ignition switch turned OFF.
- Check for proper connection to "G26-25" and "G26-24" terminals of 4WD control module connector.
- If connection is OK, measure resistance between "G26-25" terminal of 4WD control module connector and vehicle body ground.
Is resistance below 5 Ω? |
"YEL/BLK" wire is open or high resistance circuit. |
Substitute a known-good 4WD control module and recheck. |