Faulty brake switch (OBD-Codes.com, RepairPal). Wiring problem, such as a wire pinched at the brake pedal, chafed, open, or shorted to ground (all three sources). Faulty engine computer (PCM/ECM), less common (all three sources). Brake switch out of adjustment (OBD-Codes.com). Brake switch knocked out of its mount (OBD-Codes.com). Dirt or debris stopping the switch from moving (OBD-Codes.com). Moisture or corrosion at the connector pins causing an intermittent connection (OBD-Codes.com).

Replace the brake switch, following the manufacturer's install and adjustment procedure (OBD-Codes.com, RepairPal). Re-mount or adjust a switch that has come loose or is misadjusted (OBD-Codes.com). Repair an open, a short to ground, or chafed or corroded wiring in the brake switch signal circuit (all three sources). Repair or replace the engine computer, or the body control module where it runs cruise control, only after the switch and wiring test good (all three sources).

P0572🔧 Brake pedal switch / cruise controlStop and fix promptly

P0572: Brake Switch A Circuit Low (Meaning, Causes, Fixes)

Q: What does P0572 mean?

P0572 means the engine computer saw a voltage that's too low on the brake switch 'A' circuit, the switch that tells it you're pressing the brake pedal and usually also turns on the brake lights. The most common results are cruise control that won't work and brake lights that may not come on. Common causes are a faulty or misadjusted brake switch, a broken, shorted-to-ground or pinched wire near the pedal and, less often, the engine computer. The brake switch sits on the brake pedal arm under the dash. It tells the engine computer when the pedal is pressed so cruise control can switch off, and on most cars it also powers the brake lights. OBD-Codes.com says P0572 sets when the engine computer detects a low voltage condition in the cruise control/brake switch 'A' circuit, and that the 'A' may refer to a specific wire, connector or harness only your service manual can identify. GM's service information for the Chevrolet Trax gives a more specific example: there, P0572 sets when the engine computer sees a short to ground or an open on the brake signal wire while a data message from the body control module says the brakes are applied, for 8 out of 10 checks lasting more than 2 seconds. RepairPal describes the trigger differently, saying the code sets when the computer sees the vehicle slowing down without the brake switch reporting that the pedal is pressed; that is the same wording RepairPal uses for P0571 and P0573, so it doesn't explain the 'low' part. The sources also word the code slightly differently: OBD-Codes.com calls it 'Cruise Control/Brake Switch A Circuit Low' and RepairPal uses 'Brake Switch "A" Circuit Low'. OBD-Codes.com lists P0571 and P0573 as related codes and notes that on some cars the body control module (BCM), not the engine computer, runs cruise control. It is a generic code that can appear on any OBD-II vehicle.

Q: Can I keep driving with P0572?

Stop and fix promptly. Check your brake lights before driving. The same brake pedal switch usually turns on your brake lights, and both main sources list brake lights not working as a possible symptom, which means drivers behind you may not see you slowing down. RepairPal rates P0572 Urgent. OBD-Codes.com calls it moderately severe, explaining that cruise control faults are usually low priority but a possible brake switch problem is a real safety concern. If your brake lights don't come on, or stay on all the time, get it fixed before driving, and don't rely on cruise control.

Reviewed 2026-10-23 · Based on 3 cited source(s)

What P0572 means

The brake switch sits on the brake pedal arm under the dash. It tells the engine computer when the pedal is pressed so cruise control can switch off, and on most cars it also powers the brake lights. OBD-Codes.com says P0572 sets when the engine computer detects a low voltage condition in the cruise control/brake switch 'A' circuit, and that the 'A' may refer to a specific wire, connector or harness only your service manual can identify. GM's service information for the Chevrolet Trax gives a more specific example: there, P0572 sets when the engine computer sees a short to ground or an open on the brake signal wire while a data message from the body control module says the brakes are applied, for 8 out of 10 checks lasting more than 2 seconds. RepairPal describes the trigger differently, saying the code sets when the computer sees the vehicle slowing down without the brake switch reporting that the pedal is pressed; that is the same wording RepairPal uses for P0571 and P0573, so it doesn't explain the 'low' part. The sources also word the code slightly differently: OBD-Codes.com calls it 'Cruise Control/Brake Switch A Circuit Low' and RepairPal uses 'Brake Switch "A" Circuit Low'. OBD-Codes.com lists P0571 and P0573 as related codes and notes that on some cars the body control module (BCM), not the engine computer, runs cruise control. It is a generic code that can appear on any OBD-II vehicle.

Severity: can I keep driving?

Stop and fix promptly

Check your brake lights before driving. The same brake pedal switch usually turns on your brake lights, and both main sources list brake lights not working as a possible symptom, which means drivers behind you may not see you slowing down. RepairPal rates P0572 Urgent. OBD-Codes.com calls it moderately severe, explaining that cruise control faults are usually low priority but a possible brake switch problem is a real safety concern. If your brake lights don't come on, or stay on all the time, get it fixed before driving, and don't rely on cruise control.

Common symptoms

Cruise control not working at all (all three sources)
Brake lights not coming on if the switch is faulty (OBD-Codes.com, RepairPal)
Erratic cruise control, or cruise that turns on but won't engage (OBD-Codes.com)
Cruise buttons like set, resume or accelerate not working properly (OBD-Codes.com)
On the GM Trax, the check engine light does not come on for this code; the only action listed is that cruise control is disabled (GM service information)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Faulty brake switch (OBD-Codes.com, RepairPal)
Wiring problem, such as a wire pinched at the brake pedal, chafed, open, or shorted to ground (all three sources)
Faulty engine computer (PCM/ECM), less common (all three sources)
Brake switch out of adjustment (OBD-Codes.com)
Brake switch knocked out of its mount (OBD-Codes.com)
Dirt or debris stopping the switch from moving (OBD-Codes.com)
Moisture or corrosion at the connector pins causing an intermittent connection (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Have someone watch the rear of the car while you press and release the brake pedal. Brake lights that don't come on point to the switch or its wiring, and that's a safety issue to fix right away.
Look under the dash at the switch on the brake pedal arm. OBD-Codes.com says a driver's foot sometimes knocks the switch out of its mount or breaks it off, which you can see right away.
Check that the switch is adjusted correctly and that nothing is stopping it from moving freely (OBD-Codes.com).
Inspect the wiring and connector at the switch for pinched, chafed, broken or corroded wires, and clean corroded pins with electrical contact cleaner. OBD-Codes.com suggests disconnecting the circuit at both ends and doing a continuity test with a multimeter, using your service manual's wiring diagram and specs.
Check for technical service bulletins (TSBs) for your vehicle, which OBD-Codes.com recommends as the first step.

Typical fixes

Replace the brake switch, following the manufacturer's install and adjustment procedure (OBD-Codes.com, RepairPal)
Re-mount or adjust a switch that has come loose or is misadjusted (OBD-Codes.com)
Repair an open, a short to ground, or chafed or corroded wiring in the brake switch signal circuit (all three sources)
Repair or replace the engine computer, or the body control module where it runs cruise control, only after the switch and wiring test good (all three sources)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Your brake lights don't work and you can't fix the switch yourself
The switch needs a specific adjustment procedure you don't have
Wiring tests point to an open or short you can't find, or to the engine or body control module
The code comes back after a new, properly adjusted switch

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0572?

First check that your brake lights work normally. If they don't, get it fixed before driving, since drivers behind you won't see you braking. RepairPal rates P0572 Urgent and OBD-Codes.com calls it moderately severe.

What's the difference between P0572 and P0573?

P0572 means the brake switch 'A' circuit voltage is too low, while P0573 means it is too high. GM's Trax service information, for example, sets P0572 for a short to ground or an open on the brake signal wire, and P0573 for a short to voltage.

Why is my check engine light off but the code is stored?

Some vehicles don't turn on the check engine light for this code. GM's service information for the Trax says the light will not come on for P0572; it only disables cruise control.

How much does it cost to fix P0572?

None of the sources gives a repair cost for P0572. It can range from adjusting the switch to replacing it or repairing wiring, so diagnose it first.

Sources

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.