Pinpoint Test E : P188C, P188D: Notes
Diagnostic Overview
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Service Information for information about these practices. This pinpoint test is intended to diagnosis the wiring, terminals, connectors, AWD relay and PCM.
NOTE:
Fuse 70 (15A) is HOT at all times and protects multiple components. Check related systems that may be inoperative.
Refer to ALL WHEEL DRIVE (AWD) for schematic and connector information.
Normal Operation and Fault Conditions
The AWD system uses data from other systems as inputs to the PCM. The PCM uses the inputs to determine the appropriate duty cycle to send to the AWD relay on the command circuit and returns AWD relay information on the feedback circuit.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P188C | AWD Relay Module Communication Circuit | When the PCM detects an open, a short to ground or voltage on the command circuit. |
| P188D | AWD Relay Module Feedback Circuit | When the PCM detects an open, a short to ground or voltage on the feedback circuit. |
Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- Fuse
- AWD relay module
- PCM