Diagnostic Instructions
DTC Descriptor
DTC C0401 01: Transfer Case Oil Temperature Sensor Circuit Short to Battery
DTC P0401 06: Transfer Case Oil Temperature Sensor Circuit Short to Ground or Open
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Invalid
|
Transfer Case Oil Temperature Sensor Circuit
| C0401 06
| C0401 06
| C0401 01
| --
|
Circuit/System Description
The temperature sensor is a variable resistor, as the temperature increases the resistance decreases and as the temperature decreases the resistance increases.
Conditions for Running the DTC
| • | System voltage is 9-16 volts. |
Conditions for Setting the DTC
| • | System voltage is above 9 volts and below 16 volts. |
| • | For a short to voltage or actual transfer case overheat condition, the DTC will set immediately once 154°C (309°F) has been met or exceeded. |
| • | The vehicle has been driven 10 minutes at 73 km/h (45 mph) or higher for an open or short to ground condition. |
Action Taken When the DTC Sets
| • | System backup will read the transmission oil temperature. |
| • | The SERVICE 4WD indicator is set. |
| • | If the transfer case oil temperature DTC is set due to an actual overheat condition and not an electrical fault then the AWD off indicator will be set. |
Conditions for Clearing the DTC
| • | The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present. |
| • | A history DTC clears after 40 consecutive warm up cycles without a fault present. |
| • | All DTCs can be cleared using a scan tool. |
| • | Clearing DTCs will also clear failure records. |
Diagnostic Aids
| • | Check failure records for further information on the conditions present when this DTC set. |
| • | If the transfer case oil temperature sensor circuits are open or have high resistance the scan tool will indicate -40°C. |
| • | Check inline connector X103 for bent pins, corrosion, or other damage. |
| • | Check the transfer case temperature sensor for possible bent pins. |
| • | If the transfer case oil temperature circuits are shorted to voltage the scan tool will read 154°C. |
Reference Information
Schematic Reference
All-Wheel Drive Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Testing
- With the key off disconnect the transfer case oil temperature sensor at the transfer case.
- Turn the ignition on and test pin B at the transfer case for voltage using a DMM the voltage reading should be 4.8 to 5.2 volts. If the voltage is out of range check the 5 volt reference circuit for a short to ground, open, high
resistance, or short to battery. This can be done by using a DMM and testing from pin B at the transfer case and X1 pin 9 at the transfer case shift control module.
- If the 5 volt reference circuit measured within specifications then using a fused jumper, jump pin B to pin A at the transfer case. With these two pins jumped read the transfer case oil temperature on the scan tool under transfer
case data display. If the temperature reads 154°C then the circuit is testing good. If it does not show this temperature then repair the temperature sensor signal circuit for an open, high resistance, short to ground, or short to voltage. This can be done
by using a DMM and testing from pin B at the transfer case and X1 pin 1 at the transfer case shift control module. If the temperature checks good replace the transfer case temperature sensor. If voltage on the 5 volt reference is out of
range or the temperature is not indicating correctly go to the next step.
- If both the 5 volt reference circuit and the temperature sensor signal circuit test good and the voltage or temperature are indicated out of range in the above two steps then replace the transfer case shift control module.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
