Normal Operation
WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM) sends a signal, which passes through the clockspring, through circuit 151 (LB/BK) to the speed control switches. The return signal is sent through circuit 848 (DG/OG) and the clockspring.
DTC P0579 - may set when the speed control switch circuits are open, shorted to voltage or shorted to ground.
DTC P0581 - sets when the speed control switch circuits are shorted to voltage or open.
Possible Causes
- Circuit 151 (LB/BK) open, short to voltage or ground
- Circuit 848 (DG/OG) open, short to voltage
- Clockspring
- Speed control switch
- Horn switch wiring harness
- PCM