P0573 — Cruise Control/Brake Switch A Circuit Low
Drive with caution — fix soon.
What P0573 means
This code is set when the computer reads a lower-than-expected voltage on the cruise control / brake switch 'A' circuit. The typical causes are a failing brake light switch, a short to ground in the wiring, a loose or corroded connector, or a blown fuse. Since this circuit is also tied to brake lights on many cars, it's worth fixing soon, and repairs usually involve replacing the switch or fixing the wiring.
Common symptoms
- Check engine light is on
- Cruise control won't engage
- Brake lights don't work or stay on
- Cruise control disengages erratically
- Possible difficulty shifting out of Park
Common causes
- Faulty brake light switch
- Short to ground in the brake switch wiring
- Loose or corroded connector at the switch
- Blown fuse in the circuit
- Failing cruise control or body control module
Typical repair cost
$100 – $350
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0573 code?
Usually yes, but don't delay too long. The same circuit often runs your brake lights, and if those fail, drivers behind you won't see you braking. Have it checked soon.
How much does it cost to fix a P0573 code?
Typical repairs run $100 to $350. Replacing the brake light switch is cheap, while tracing down a wiring short or replacing a module costs more.
Is a P0573 code serious?
It's moderate severity. The car drives fine, but because the brake switch can affect brake lights and the shift interlock, it's worth fixing promptly for safety.
What does 'circuit low' mean in a P0573 code?
It means the computer is seeing less voltage than it expects on the brake switch circuit, often from a short to ground or a failing switch. The system reads this as an invalid signal and stores the code.