Normal Operation
WARNING: This page is about a different car, the 2008 Mercury Sable, 2008 Ford Taurus X, and 2008 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
The PCM sends a signal through circuit VES10 (WH) to the speed control switches which passes through the clockspring. The return signal is sent through circuit RES08 (GN/BN) and the clockspring.
- DTC P0579 (Speed Control Switch Circuit Failure) - may set when the speed control switch circuits are open, shorted to voltage or ground.
- DTC P0581 (Speed Control Switch Circuit Failure) - sets when the speed control switch circuits are open or shorted to voltage.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Speed control switch
- PCM