Pinpoint Test F : Four-Wheel Drive (4WD) Clutch Field Coil - Electrical: Notes
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
Refer to Wiring Diagram Four Wheel Drive Systems for schematic and connector information.
Normal Operation
When the transfer case is in 4A and 4H modes, the TCCM provides a PWM voltage to the transfer case clutch field coil. The energized field coil moves a ball and ramp cam to engage a clutch as necessary to provide torque to the front axle.
The TCCM 4WD clutch field coil driver monitors the circuit for open circuit, short to power, and short to ground. If an electrical fault is detected, the TCCM will store a DTC
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P1825:00 | 4-Wheel Drive Clutch Relay Open Circuit: No Sub Type Information | This DTC sets when TCCM detects an open circuit. The TCCM disables transfer case clutch operation. |
| P1826:00 | 4-Wheel Drive Low Clutch Relay Circuit To Battery: No Sub Type Information | This DTC sets when TCCM detects a short to voltage. Transfer case clutch operation, though disabled by the TCCM, is fully engaged when this DTC is present. |
| P1827:00 | 4-Wheel Drive Low Clutch Relay Circuit To Ground | This DTC sets when TCCM detects a short to ground. The TCCM disables transfer case clutch operation. |
Possible Sources:
- Fuse
- Wiring, terminals or connectors
- Transfer case clutch field coil