Chevrolet P0573 Code – How To Diagnose And Repair Your Brake Switch
The chevrolet p0573 code indicates that your vehicle’s engine control module (ECM) has detected an abnormally high voltage signal from the brake pedal position switch circuit. This fault often disables cruise control and can trigger warning lights on your dashboard, requiring immediate attention to ensure your brake lights function correctly.
Few things are as frustrating as seeing a “Check Engine” light pop up while you are heading out for a weekend trail ride or a long highway commute. If you are dealing with a chevrolet p0573 code, you are likely noticing that your cruise control has stopped working or that your brake lights are acting erratically.
The good news is that this is usually a localized issue. It typically involves the brake switch itself or a simple wiring fault near the pedal assembly. We will walk through the diagnostic steps to identify the root cause, ensuring you get back on the road with confidence.
Understanding the Chevrolet P0573 Code and Its Impact
In modern vehicles, the brake pedal position sensor serves two critical purposes. First, it tells the computer to turn on your rear brake lights. Second, it sends a signal to the powertrain control module to disengage the cruise control the moment you touch the pedal.
When the computer sees a voltage that stays “high” for too long—suggesting the circuit is permanently closed or shorted—it throws the chevrolet p0573 code. Because safety is the priority, the vehicle disables the cruise control system to prevent a dangerous situation where the engine continues to accelerate despite your braking input.
You might notice your brake lights staying on even when the pedal is released. This is a clear indicator that the switch is either physically stuck or internally shorted. Always prioritize verifying your brake light operation before driving in traffic.
Preliminary Inspection and Safety Precautions
Before you grab your tools, start with a visual inspection. Many of these issues are caused by debris or loose floor mats interfering with the pedal travel.
- Check for floor mats bunched up behind the brake pedal arm.
- Look for any aftermarket wiring or accessories tapped into the brake light circuit.
- Ensure the pedal returns fully to the “up” position when you release your foot.
If you have recently installed a trailer light harness or an aftermarket alarm, double-check those connections. Often, a poor ground or a stray wire can cause voltage feedback, triggering the chevrolet p0573 code. If the physical pedal travel is clear, it is time to move to electrical diagnostics.
The Diagnostic Decision Flow
To help you isolate the problem, use this simple decision flow. It will save you from replacing perfectly good parts while you troubleshoot the brake switch circuit.
- Check Brake Lights: If they are always on, replace the brake switch.
- Scan Tool Data: Use a scanner to monitor the “Brake Switch” PID. Does it change when you press the pedal?
- Connector Check: Unplug the switch and inspect for green corrosion or pushed-out pins.
- Voltage Test: Use a multimeter to verify 12V power is present at the connector feed wire.
Performing a Wiring Harness Continuity Test
If the switch tests fine but the code remains, you may have a short-to-power in the wiring harness. This is common in older vehicles where insulation may have rubbed through against the metal pedal bracket.
Set your multimeter to the continuity or Ohms setting. With the switch unplugged, check the wires leading back to the harness. You are looking for an unintended connection to a power source.
If you find a frayed wire, repair it using high-quality heat-shrink butt connectors. Avoid using simple electrical tape, as the vibration of daily driving or off-road terrain will quickly cause the connection to fail again.
Brake Switch Replacement Procedures
If your testing confirms the switch has failed internally, replacing it is a straightforward DIY task. Most Chevrolet models utilize a twist-lock or clip-in style switch located at the top of the brake pedal arm.
Always disconnect the negative battery terminal before starting to prevent any electrical shorts. Reach up behind the dash, disconnect the electrical connector, and remove the old switch by rotating it or releasing the retaining clip.
When installing the new part, ensure it is properly calibrated. Some switches require you to hold the brake pedal down while inserting the switch to ensure the plunger is set to the correct depth. Failure to do this correctly can cause the switch to break upon first use.
When to Consult a Professional
While the chevrolet p0573 code is generally manageable, there are times when you should consult a professional mechanic. If you have replaced the switch and the wiring appears intact, the issue could reside within the Body Control Module (BCM) or the ECM.
Intermittent electrical faults can be notoriously difficult to track down without specialized diagnostic equipment. If you notice other symptoms like erratic gauge behavior or communication loss, it may be time to seek a shop with advanced electrical troubleshooting capabilities.
Frequently Asked Questions About the P0573 Code
Can I drive my car with the P0573 code active?
Technically, the car will drive, but you should not use cruise control. Most importantly, check if your brake lights are stuck on or not working at all; if they are not working, the vehicle is not safe for road use.
Is the brake switch expensive to replace?
No, the brake pedal position sensor is typically an inexpensive part. You can usually find a high-quality replacement at most auto parts stores for a reasonable price.
Do I need to reset the computer after fixing the switch?
In many cases, the code will clear itself after a few successful drive cycles where the system detects normal operation. However, using a scan tool to clear the code immediately will confirm your repair was successful.
Could a blown fuse cause this code?
Yes. If the fuse supplying power to the brake light circuit is blown, the system might register an open circuit or a voltage discrepancy, which can sometimes trigger related fault codes.
Diagnosing your vehicle’s electrical system can be intimidating, but following a logical process makes it much easier. By starting with the simplest components like the switch and connector, you can save yourself time and money. Stay patient, stay organized, and enjoy the satisfaction of fixing it yourself. Stay safe and keep your ride in top shape!
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