Pinpoint Test C : DTC P188B: Notes
WARNING: This page is about a different car, the 2018 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
DTC P188B
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 time to send a signal and have the AWD relay module energize the Active Torque Coupling (ATC) solenoid.
The AWD_CLTCH_CMD PID percentage displayed on the scan tool is an inverse value. 95% = Clutch is released, 5% = Clutch fully applied.
NOTE:
0% is an invalid command. A DTC may set if 0% is commanded using output state control.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P188B | AWD Clutch Control Circuit | When the PCM detects an open, a short to ground or voltage on the Active Torque Coupling (ATC) solenoid voltage supply and/or return circuit. |
Possible Causes
- Wiring, terminals or connectors
- Active Torque Coupling (ATC) solenoid (part of the Rear Drive Unit (RDU))
- Active Torque Coupling (ATC) Clutch
- AWD relay module
- PCM
Visual Inspection and Diagnostic Pre-checks
- Active torque coupling (ATC) solenoid harness