DTC C1250: Coupling Air Temperature Sensor Circuit Open: Troubleshooting

WARNING: This page is about a different car, the 2011 Suzuki SX4. However, it is still accessible from the selected car via links, so may be relevant.

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.