The OBD2 code P0572 points to an issue within the Cruise Control/Brake Switch A Circuit, indicating a detected voltage level that is lower than expected. This code is crucial because the cruise control and brake switch play key roles in vehicle safety and efficiency, allowing the vehicle to maintain a constant speed set by the driver and disengage cruise control when the brake is applied.
P0572 quick overview
| Meaning | P0572: Cruise Control/Brake Switch A Circuit Low |
| Is it serious? | Yes, it can affect vehicle safety and cruise control functionality. |
| Possible causes | – Faulty brake switch – Wiring harness issues (loose connections, corrosion, pinched wires) – PCM issues in rare cases |
| How to diagnose? | Inspect the brake switch for damage or misalignment. Check wiring harness and connectors for loose connections or corrosion. Test the brake switch functionality under various conditions. Review circuit diagrams to identify common ground points and inspect for any signs of damage. Inspect for chafed wiring near potential rubbing points. |
P0572 Meaning
When your car shows the P0572 code, it means there’s a problem with the part of your car that turns off the cruise control when you hit the brakes. This is important because it helps keep you safe by making sure the car doesn’t keep speeding up when you’re trying to slow down.
The issue might be a simple fix, like a loose wire or a brake switch that’s not working right, but it’s crucial to address it to ensure your car’s cruise control and brake systems work properly together.
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How to fix P0572 – learn from mechanics
I looked into P0572 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Pontiac
Vehicle Information 2008 Pontiac Grand Prix GXP 5.3L Electronic
Issue + Repair History
- Transmission slips intermittently.
- Multiple trouble codes:
- U0073: Control Module Communication Bus Off
- C0240: PCM Traction Control Not Allowed
- P0562: System Voltage Low
- P0572: Cruise Control/Brake Switch A Circuit Low
- P0073: Cruise Control/Brake Switch A Circuit High
- P0711: Transmission Temperature Sensor Circuit Out of Range
- P0716: Input Turbine Sensor Circuit Out of Range
- P0717: No/Low Input Turbine Speed Sensor Signal
Other OBD2 Codes + Test Results
- U0073 is the only active code.
- No additional test results mentioned.
Mechanic Suggestions
- Check for loose connections, bad grounds, water intrusion in connectors, or PCM issues.
- Inspect circuit diagrams to identify common ground points.
- Check connectors for any signs of damage or water intrusion.
- Inspect for chafed wiring near the A/C dryer.
- Review power and ground connections using diagrams.
- Inspect transmission harness for any signs of rubbing against the block or bell housing.
Final Fix Pinched wires were found from the factory on the fuse box on the passenger side near the firewall. The issue was resolved after fixing the wiring.
Case #2: Toyota
Vehicle Information 2015 Toyota Camry LE 2.5L Automatic
Issue + Repair History
- Cruise control/brake switch A circuit low (P0572) trouble code.
- No previous repair history mentioned.
- Symptoms include intermittent failure of the cruise control system.
Other OBD2 Codes + Test Results
- P0572 is the only trouble code mentioned.
- Live data tests show inconsistent readings from the brake switch circuit.
Mechanic Suggestions
- Inspect the brake pedal position sensor for any signs of damage or misalignment.
- Check the wiring harness and connectors associated with the brake switch for any loose connections or corrosion.
- Perform a thorough diagnostic of the cruise control system to identify any additional faults.
- Test the brake switch functionality under various conditions to pinpoint the root cause of the circuit low issue.
Final Fix After thorough inspection, it was found that the brake switch wiring harness had a loose connection, causing intermittent failure of the circuit. The connection was tightened, resolving the P0572 trouble code and restoring proper functionality to the cruise control system.
Case #3: Honda
Vehicle Information 2012 Honda Civic LX 1.8L Automatic
Issue + Repair History
- Experiencing problems with the cruise control system.
- P0572 trouble code (cruise control/brake switch A circuit low) is present.
- No previous repair history provided.
- Complaints of cruise control not engaging consistently.
Other OBD2 Codes + Test Results
- Only the P0572 trouble code mentioned.
- Live data tests reveal irregularities in brake switch signal readings.
Mechanic Suggestions
- Inspect the brake pedal assembly for any signs of wear or damage.
- Check the brake light switch and its associated wiring for proper functionality.
- Perform a detailed examination of the cruise control module for potential faults.
- Test the brake switch under various conditions to simulate normal driving scenarios and identify any intermittent issues.
Final Fix Upon inspection, it was discovered that the brake switch was not properly adjusted, leading to inconsistent signals and triggering the P0572 trouble code. The brake switch was readjusted to the manufacturer’s specifications, resolving the issue and restoring normal operation of the cruise control system.
How to diagnose P0572
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Inspect the brake switch | Check for damage, misalignment, or failure. |
| Check wiring and connectors | Look for loose connections, corrosion, or damage. |
| Test brake switch functionality | Verify it operates correctly under all conditions. |
| Review circuit diagrams | Identify common points and inspect for damage. |
| Inspect for chafed wiring | Look near the A/C dryer and areas prone to rubbing. |
| Inspect the brake pedal position sensor | Check for signs of damage or misalignment. |
| Perform a diagnostic on the cruise control system | Identify any faults beyond the brake switch circuit. |
| Adjust the brake switch to manufacturer specs | Ensure proper adjustment for consistent signals. |
| Fix pinched wires | Repair any found pinched wires affecting the circuit. |
These cases from a Pontiac Grand Prix, Toyota Camry, and Honda Civic show that while the P0572 code might appear across different makes and models, the root cause often revolves around issues with the brake switch and its circuit. Ensuring these components are in good condition and correctly connected is crucial for the safe operation of the vehicle’s cruise control system.
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I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.
Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)