P0579
Cruise Control Multi-Function Input A Circuit Range/Performance
Cruise control
Generic OBD-II
Low
What it means
P0579 means the cruise-control multi-function switch "A" circuit is reading outside its normal range — the switch input is higher or lower than expected. This typically makes cruise control unresponsive or erratic. It has no effect on how the engine starts or runs.
Low
Can I keep driving? Safe to drive — the fault only disables or disrupts cruise control; starting and engine performance are unaffected.
Common symptoms
What you'll notice
- Cruise control inoperative or erratic
- Cruise-control buttons unresponsive
- Cruise-control or check-engine warning light on
Common causes
Most likely first
- Faulty cruise-control multi-function switchLikely
- Damaged wiring or connectors in the switch circuitCommon
- Loose or corroded electrical connectionsCommon
- Failed cruise-control module or ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note the conditions when it set.
- Measure the switch's resistance/voltage against spec across each button position.
- Inspect and repair wiring and connectors in the switch circuit.
- Replace the switch if its signal reads out of range.
- Replace the module only if the wiring and switch check good.
FAQ
Quick answers
Is it safe to drive with P0579?+
Yes — only the cruise-control system is affected. The rest of the vehicle operates normally.
Can I just clear P0579?+
It returns until the multi-function switch or its wiring is repaired.
Related codes
Often seen with P0579
Read & clear P0579 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX