P0570 is a diagnostic trouble code related to your vehicle’s cruise control system, specifically a malfunction in the brake switch or cruise control cancel circuit. When this code sets, your car’s computer has detected an electrical issue that can disable or interfere with cruise control operation. While it usually won’t leave you stranded, it can be annoying on long trips and may indicate a developing electrical or brake light circuit problem. Understanding what P0570 means, how it shows up, and how to fix it will help you avoid bigger headaches later.
What Does P0570 Mean?
P0570 is defined as “Cruise Control / Brake Switch A Malfunction” or a similar description depending on the manufacturer. In simple terms, your ECU (engine control unit) is seeing an incorrect or inconsistent signal from the brake pedal switch or the wiring that tells the cruise control system when you’re pressing the brake.
The cruise control needs a clean, reliable signal from the brake switch so it can instantly cancel throttle when you hit the brakes. If the ECU sees a voltage that’s out of range, stuck on, stuck off, or flickering, it sets P0570 and may disable cruise control as a safety measure.
Quick Reference
- Code: P0570
- System: Cruise control / brake switch circuit
- Severity: Low to moderate (safety-related for cruise, not engine damage)
- Common Fix: Adjust or replace brake switch, repair wiring or connectors
- Driveability: Vehicle usually drives fine but cruise control may not work
Real-World Example / Field Notes
In the shop, I often see P0570 after customers complain that their cruise control “just stopped working” or cancels randomly on the highway. One case involved a compact SUV where the brake lights were slightly delayed when pressing the pedal. The scan tool showed the brake switch input flickering in live data. The switch looked fine from the outside, but internally the contacts were worn. Replacing and properly adjusting the brake switch cleared P0570 and restored smooth cruise control operation. The fix was simple, but catching it early prevented a potential brake light failure.
Symptoms of P0570
- Cruise control inoperative – Cruise won’t set or engage at all.
- Cruise control drops out – System cancels randomly while driving.
- Brake lights abnormal – Brake lights stuck on, delayed, or not working in some cases.
- Warning lights on – Check engine light or cruise control warning indicator illuminated.
- Intermittent operation – Cruise works sometimes and fails other times, especially over bumps.
- Harder to maintain speed – No cruise control on long trips, leading to driver fatigue.
- Possible ABS/traction alerts – On some vehicles, related stability or ABS warnings may appear if signals conflict.
Common Causes of P0570
Most Common Causes
- Faulty brake pedal switch: Worn internal contacts, sticking plunger, or failed electronics inside the switch.
- Misadjusted brake switch: Switch not aligned correctly with the pedal, causing constant “brake on” or “brake off” signal.
- Damaged wiring at brake pedal: Chafed, pinched, or broken wires near the pedal assembly or under the dash.
- Corroded connectors: Moisture or age-related corrosion in the brake switch or cruise control harness connectors.
- Aftermarket accessories: Poorly installed remote starters, alarms, or trailer wiring tapping into the brake circuit.
Less Common Causes
- Faulty cruise control module: On vehicles with a separate cruise module, internal failure can misread the brake signal.
- ECU software glitch: Rarely, a control module needs a software update (reflash) to correct overly sensitive monitoring.
- Faulty brake light bulbs or LED assemblies: On some modern cars, incorrect resistance from non-OEM LED bulbs can confuse the system.
- Ground issues: Weak or corroded ground points affecting shared circuits between brake lights and control modules.
- Damaged clockspring or steering column wiring: On certain models, cruise and brake cancel signals route through the steering column.
Diagnosis: Step-by-Step Guide
You’ll want a basic scan tool (preferably one that can read live data), a digital multimeter, and simple hand tools. Access to wiring diagrams or service information for your specific vehicle helps a lot. If you’re comfortable working under the dash and around electrical connectors, you can do some of this at home.
- Confirm the code: Connect your scan tool, read stored and pending codes, and verify P0570 is present. Note any related codes (brake switch, ABS, cruise control).
- Check cruise control operation: Try to set cruise at highway speed. See if the indicator comes on, flashes, or does nothing. This helps you understand if the system is completely dead or intermittent.
- Inspect brake lights: With the ignition on, press and release the brake pedal. Confirm brake lights turn on and off immediately. Look for lights stuck on or delayed response.
- Visual inspection under dash: Locate the brake pedal switch at the top of the pedal arm. Check for loose mounting, broken brackets, or obvious damage. Wiggle the connector and harness gently while watching for flickering brake lights.
- Check live data: On the scan tool, look for data PIDs like “Brake Switch,” “Brake Pedal Status,” or “Cruise Cancel.” Press and release the pedal. The status should switch cleanly between ON and OFF with no lag or flicker.
- Test brake switch voltage: With a multimeter, back-probe the brake switch connector following a wiring diagram. Verify power feed, ground, and signal output change as you press the pedal. A signal that never changes or is always high/low indicates a bad switch or wiring.
- Inspect wiring and connectors: Trace the harness from the switch a short distance. Look for rubbed insulation, tight bends, or previous repairs. Unplug the connector and check for corrosion, bent pins, or moisture.
- Check for aftermarket add-ons: Look for spliced wires from remote starters, alarm systems, or trailer brake controllers tied into the brake light circuit. Poor splices or Scotch-lock connectors can cause voltage issues.
- Advanced checks (if needed): On some vehicles, you can use Mode $06 or manufacturer-specific data to see how many times the monitor has failed. If all hardware tests fine, a software update or deeper module testing may be necessary at a professional shop.
Pro tip: Many “bad” brake switches are actually just misadjusted. Before replacing, check the switch position relative to the pedal. Often, a simple adjustment so the plunger fully releases and engages with pedal travel will clear P0570.
Possible Fixes & Repair Costs
Most P0570 repairs are straightforward and not too expensive. Typical fixes include adjusting or replacing the brake pedal switch, repairing damaged wiring, cleaning or replacing corroded connectors, or addressing any poorly installed aftermarket equipment. In rarer cases, a cruise control module or ECU software update is needed. At a repair shop, you’re usually looking at about $80–$180 for a brake switch replacement, $120–$300 for wiring diagnosis and repair, and $150–$400 if a module or reflash is involved. Costs vary with vehicle make, labor rates, and how hard the parts are to access.
Can I Still Drive With P0570?
In most cases, you can still drive with P0570 without immediate risk of engine damage. The main impact is losing reliable cruise control, which can make long trips more tiring. However, if the brake switch or wiring is severely faulty, your brake lights may not function correctly, which is a serious safety issue and can get you a ticket. If you notice any odd brake light behavior or additional warning lights, you should treat the repair as a priority and avoid night or highway driving until it’s fixed.
What Happens If You Ignore P0570?
Ignoring P0570 can turn a simple, inexpensive repair into a bigger problem. Over time, a failing brake switch or damaged wiring can lead to complete brake light failure, intermittent ABS or traction control issues, and potential rear-end collision risk because drivers behind you can’t see when you’re braking. It can also mask new problems if you get used to driving with the check engine light on.
Related Codes
- P0574 – Cruise Control System Vehicle Speed Too High
- P0573 – Brake Switch “A” Circuit High
- P0572 – Brake Switch “A” Circuit Low
- P0571 – Brake Switch “A” Circuit
- P0569 – Cruise Control Coast Signal
- P0568 – Cruise Control Set Signal
- P0567 – Cruise Control Resume Signal
- P0566 – Cruise Control Off Signal
- P0565 – Cruise Control On Signal
- P0564 – Cruise Control Multi-Function Input “A” Circuit
Key Takeaways
- P0570 points to a problem with the cruise control brake switch circuit, not the engine itself.
- Common symptoms include inoperative or unreliable cruise control and possible brake light issues.
- The most frequent cause is a faulty or misadjusted brake pedal switch or related wiring.
- Diagnosis usually involves a scan tool, basic electrical checks, and a visual inspection under the dash.
- Repairs are often affordable if handled early, typically involving switch replacement or wiring repair.
- Don’t ignore P0570 if brake lights act strange—this becomes a safety concern, not just an inconvenience.
Vehicles Commonly Affected by P0570
P0570 can show up on many modern vehicles with electronic cruise control, but it’s especially common on certain brands. You’ll often see it on Volkswagen and Audi models, various Toyota and Lexus vehicles, and some Hyundai and Kia cars and SUVs. It also appears on GM and Ford vehicles, especially those with heavy use of shared brake switch signals for ABS, traction control, and cruise. Compact cars, crossovers, and light-duty trucks that see a lot of commuting or stop-and-go driving tend to wear out brake switches sooner.
FAQ
Can I clear P0570 myself with a scan tool?
Yes, you can clear P0570 with a basic OBD2 scanner, but if the underlying issue isn’t fixed, the code will usually return. Always diagnose and repair the cause before relying on a simple reset.
Is P0570 dangerous to drive with?
P0570 itself doesn’t usually threaten the engine or transmission, but it can be dangerous if it affects your brake lights. If your brake lights are stuck on or not working, you should avoid driving until the problem is repaired.
How do I know if the brake switch is bad or just misadjusted?
If the switch looks intact and the brake lights work but stay on too long or come on with very light pedal pressure, it may just need adjustment. If live data or voltage tests show no change when you press the pedal, or the lights don’t respond at all, the switch is likely faulty.
Can a bad brake light bulb cause P0570?
On most vehicles, a simple burned-out bulb won’t trigger P0570. However, on some models with sensitive monitoring or aftermarket LED bulbs with incorrect resistance, the ECU can misinterpret the signal and set related brake or cruise codes.
How long does it take a shop to fix P0570?
Diagnosis and repair for a typical brake switch issue usually take about 0.5–1.5 hours. Wiring problems or module issues can extend that time, especially if the harness is hard to access or additional testing is needed.