P0571 code: Cruise Control/Brake Switch A Circuit
P0571 means cruise Control/Brake Switch A Circuit. The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0571 means
P0571 points at the brake light switch circuit — the small switch on the brake pedal that tells the car when you're braking. The computer compares the brake switch signal against what the car is doing, and this code sets when the signal doesn't add up. The good news is that the brake light switch itself is one of the cheapest parts on the car and is usually easy to reach at the top of the pedal. Beyond disabling cruise control, a bad switch can affect your brake lights and the shift interlock that lets you move the shifter out of Park. A misadjusted switch, a blown brake light fuse, or a wiring problem at the pedal can set the same code.
P0571 symptoms
- Cruise control won't set or drops out
- Brake lights stuck on or not working
- Shifter hard to move out of Park
- Check-engine light with no drivability change
What it costs to fix P0571
Typical range: $20–$150 · about ~0.2–0.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Brake light switch | $15–$60 | ~0.2–0.5 hrs |
| Fuse or wiring repair at the pedal | $5–$50 | ~0.2–0.5 hrs |
This is one of the cheaper codes to fix — the switch is an inexpensive part mounted right at the brake pedal, and on many cars it's a quick swap. Some switches need a specific adjustment procedure, which is where a shop earns its labor charge.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0571 for my exact vehicle →
How to fix P0571
Easy — basic tools, most owners can do this
- Check every brake light with a helper
Have someone watch the rear while you press the pedal, or back up to a garage door or shop window and use the mirrors. All brake lights, including the center high-mounted one, should come on instantly and go off the moment you release the pedal. Lights that are dead or stuck on mean the car isn't safe in traffic until this is sorted.
- Test the stop-lamp fuse and bulbs
Find the brake or stop-lamp fuse in the owner's manual and test it. A blown fuse can kill the lights and the switch signal together, and if a new one blows too, look for a shorted socket or damaged trailer wiring. A single burnt bulb usually won't set this code, but replace any you find while you're there.
- Watch the brake switch status on live data
Many vehicles use a dual-circuit switch: one contact closes and the other opens as the pedal moves, and the computer flags any mismatch between them. On a scan tool, both brake switch values should flip the instant you touch the pedal. If one changes late or never changes, the switch is misadjusted or failing.
- Inspect the switch adjustment and pedal stop
Look up at the top of the brake pedal with a flashlight. On many cars a small plastic bumper on the pedal arm presses the switch plunger, and when that bumper crumbles or falls out the brake lights stay on and this code sets. Self-adjusting switches must be reset using the procedure in the service manual, not just pushed in.
- Replace the switch and confirm cruise and shift lock
If the switch is properly adjusted but its signals still disagree, replace it — usually a twist-lock part with a single connector. Check that connector for heat damage, then confirm the brake lights, cruise control, and the shift lock release from Park all work before calling it done.
DIY or shop? This is among the easiest codes to fix at home: the switch is cheap, typically held by a twist-lock or a single clip, and reachable from the driver's footwell with a flashlight and some patience lying under the dash. Use a shop if the switch needs an adjustment procedure you can't find, if the wiring fault is up behind the dash, or if the brake lights still misbehave with a new switch fitted. Don't drive with non-working brake lights in the meantime.
Tools for the DIY steps: Flashlight · Test light or multimeter · Scan tool with live data · Basic hand tools · Spare brake light fuse and bulbs
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0571.
Start a case with P0571 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0571?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0571: common questions
Can I drive with P0571?
That depends first on your brake lights — verify them before anything else. The practical losses with this code are cruise control and possibly the shift interlock. If the brake lights are out, fix it before driving.
Why won't my cruise control work with this code?
Cruise control must know instantly when you touch the brake so it can disengage. If the brake switch signal is unreliable, the system disables cruise entirely as a safety measure. Fixing the switch circuit normally restores it.
Is the brake light switch expensive?
No — it's typically one of the cheapest electrical parts on the car, and it mounts at the top of the brake pedal where it's usually easy to reach. Many people replace it themselves; a shop visit is still a short job.
Why is my shifter stuck in Park with P0571?
Most automatics use the brake switch signal to release the shift interlock. If the switch has failed, the car may not see your foot on the brake and refuses to release the shifter. Most cars have a manual shift-lock override slot near the shifter to get you moving in the meantime.
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0571 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0571 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.