Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Normal Operation
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 (Cruise Control Multifunction Input A Circuit Range/Performance) - may set when the speed control switch circuits are open, shorted to voltage or shorted to ground.
DTC P0581 (Cruise Control Multifunction Circuit High) - sets when the speed control switch circuits are shorted to voltage or open.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- PCM not configured for speed control
- Clockspring
- PCM
- Speed control switch
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.