OBD-II Code · Cruise
P0571
Cruise/Brake Switch A Circuit
Severity
medium
Worth booking. It costs fuel, emissions or comfort until it is fixed.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$30–$150
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Brake switch fault affecting cruise.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Cruise drops out
- Brake lights stuck on
Likely causes
- Failed brake switchMost common
- Wiring
Read the full diagnostic procedureP0571 sets when the PCM detects an implausible signal pattern from the primary brake switch (the switch on the brake pedal bracket that signals brake…
P0571 sets when the PCM detects an implausible signal pattern from the primary brake switch (the switch on the brake pedal bracket that signals brake-light activation to the PCM, BCM, and cruise-control module). Modern systems use two redundant switches; P0571 typically triggers when the two disagree, or when the primary switch fails to change state during conditions where braking is inferred (deceleration plus throttle closed).
Cheapest-first
- with key on, engine off, push the brake pedal and watch the brake switch PID on a scan tool.
- It should toggle cleanly from inactive to active within the first half-inch of pedal travel.
- If the PID is stuck on (brake-applied with pedal up), the switch is misadjusted, the brake pedal bumper has crumbled (very common on Hondas), or the switch internals are stuck.
- If the PID never activates, check the brake light fuse and bulbs first; a blown fuse from a stuck-on switch is the underlying cause as often as switch failure itself.
- Expensive misdiagnosis: chasing transmission shift-quality or cruise-control codes that all stem from a $25 brake switch.
Vehicle-specific patterns2007-2014 Chevrolet Silverado, GMC Sierra, Tahoe, Suburban, and Yukon are the GM-wide poster child for brake switch failure; the switch's internal co…
- 2007-2014Chevrolet Silverado, GMC Sierra, Tahoe, Suburban, and Yukon are the GM-wide poster child for brake switch failure; the switch's internal contacts pit and the cruise control drops out before P0571 sets.
- 2003-2007Honda Accord and 2003-2011 Honda Element have the famous TSB for the brake pedal rubber bumper (the small rubber stopper the switch plunger rides on) crumbling and falling out, leaving the switch perpetually closed; the $3 bumper grommet is the fix.
- 2004-2008Ford F-150 develops a corroded brake-switch connector under the dash that intermittently opens the circuit during humid weather.
- 2005-2010Dodge Ram 1500 and 2500 has the brake switch fall out of adjustment after pedal bracket flex, especially after towing.
Estimated repair$30 to $260.
Look up another code
P0571 — frequently asked
What does a P0571 code mean?
Brake switch fault affecting cruise.
What causes a P0571 code?
Common causes: Failed brake switch; Wiring.
What are the symptoms of a P0571 code?
Typical symptoms: Cruise drops out; Brake lights stuck on.
Is it safe to drive with a P0571 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $30-$150.
How do I diagnose a P0571 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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