P0578 — Cruise Control Multi-Function Input A Circuit Stuck
Drive with caution — fix soon.
What P0578 means
This code means the cruise control multi-function input A signal appears stuck and isn't changing as the computer expects. It usually points to a sticking or failed cruise control switch, but corroded wiring or a bad connector can cause it too. It's a common, fixable fault that typically involves a switch or wiring repair rather than major engine work.
Common symptoms
- Check engine light is on
- Cruise control will not turn on or set
- Cruise control buttons feel stuck or unresponsive
- Cruise control disengages unexpectedly
- Cruise warning light may illuminate
Common causes
- Stuck or worn cruise control switch
- Corroded or damaged wiring in the input circuit
- Faulty connector or poor contact
- Internal switch contact failure
- Failing cruise control or engine control module
Typical repair cost
$100 – $350
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0578 code?
Yes, in most cases. Your engine runs normally, but cruise control may be unavailable or unreliable, so be ready to control your speed yourself until it's fixed.
How much does it cost to fix a P0578 code?
Expect roughly $100 to $350. A simple wiring or connector repair is on the low end, while replacing a stuck cruise control switch or module costs more.
Is a P0578 code serious?
It's a moderate concern. It won't damage your engine, but a stuck input usually means a failing switch or wiring that's best addressed before the feature fully quits.
What does a stuck cruise control input mean?
It means the computer sees the same input signal that won't change, often from a sticking switch. The system disables cruise control until the input behaves normally again.