C144E
C144E-FRONT DIFFERENTIAL POSITION SENSOR PERFORMANCE
For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams
- When Monitored:
The ignition on. Disconnecting Stabilizer Bar Switch in the FR/RR position.
- Set Condition:
The FDCM detects that the Front Differential Position Sensor is in an unexpected state.
Diagnostic Test
1. ACTIVE DTC
CAUTION: Before removing the FDCM harness connector, clean the connector and locking cam area of dirt and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on the harness connector or module. Do not force the assist arm when releasing or installing the harness connector.
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the DTC active at this time?
Yes
- Go To 2
No
- Go To6
2. FRONT DIFFERENTIAL POSITION SENSOR WIRING
NOTE: Before continuing with the below diagnostic test, ensure the FDCM harness connector seal is installed correctly. Inspect the terminals on both harness connector and the module for damage. Failure to do so can result in misdiagnoses of the system.
Using the scan tool, actuate the Front Locker Solenoid.
Monitor the Front Differential Position Sensor State.
Wiggle the related wiring harness from the FDCM to the Front Locker Solenoid connector at the axle.
With a scan tool, actuate the Front Locker Solenoid.
Does the state on the scan tool change while wiggling the wiring harness?
Yes
- Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Check the Locker Solenoid terminals and connectors for corrosion and/or dirt that may compromise the connection. Repair as necessary.
- Perform FDCM VERIFICATION TEST. Verification Tests
No
- Go To 3
3. FRONT DIFFERENTIAL POSITION SENSOR OPERATION
Turn the ignition off.
Disconnect the Front Locker Solenoid harness connector.
Ignition on, engine not running.
Using a jumper wire, jumper across from the (T522) Front Locker Sensor Sense circuit and the (T521) Locker Sensor Supply circuit in the Front Locker Solenoid harness connector.
While monitoring the sensor state on the scan tool, tap the jumper wire on and off the (T522) Front Locker Sensor Sense circuit terminal. Hold the jumper wire on and off the terminal for a minimum of 3 seconds.
Does the state change on the scan tool while tapping the terminal?
Yes
- Replace the Front Locker Solenoid.
- Perform FDCM VERIFICATION TEST. Verification Tests
No
- Go To 4
4. (T522) FRONT LOCKER SENSOR SENSE CIRCUIT OPEN
Turn the ignition off.
Disconnect the FDCM harness connector.
Measure the resistance of the (T522) Front Locker Sensor Sense circuit between the Front Locker Solenoid harness connector and the FDCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the open in the (T522) Front Locker Sensor Sense circuit.
- Perform FDCM VERIFICATION TEST. Verification Tests
5. FDCM
NOTE: Before continuing, check the FDCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes
- Repair as necessary.
- Perform FDCM VERIFICATION TEST. Verification Tests
No
- Replace and program the Final Drive Control Module.
- Perform FDCM VERIFICATION TEST. Verification Tests
6. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle test the wiring harness and connectors while checking for shorted and open circuits.
Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset.
Were there any problems found?
Yes
- Repair as necessary.
- Perform FDCM VERIFICATION TEST. Verification Tests
No
- Test Complete.