Normal Operation
WARNING: This page is about a different car, the 2010 Ford Pickup, 2010 Ford F550 Super Duty, 2010 Ford F450 Super Duty, and 2010 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Mode Select Switch (MSS) communicates the operator's choice to the 4X4 control module. The 4X4 control module controls the shift solenoid, transfer case motor and Pulse Vacuum Hublock (PVH) as necessary. If the vehicle is not responding to the operator's intentions, systematically check the necessary inputs and outputs of the MSS and the 4X4 control module. Check all circuits for opens and shorts to power or ground.
- DTC P1812 (4-Wheel Drive Mode Select Circuit Failure) - Fault sets when 4X4 control module senses an open circuit. Four-Wheel Drive (4WD) system mode cannot be changed.
- DTC P1815 (4-Wheel Drive Mode Select Short To Ground) - Fault sets when 4X4 control module detects a short to ground. 4WD system mode cannot be changed.
This pinpoint test is intended to diagnose the following:
- MSS
- Circuitry
- 4X4 control module