OBD-II Generic Error Code P0573: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
P0573
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code P0573 means your car's computer has detected a high voltage signal from the brake switch A circuit. This usually indicates a faulty brake switch, a wiring issue, or a short circuit. The brake light switch tells the computer when you press the brake pedal; a high reading can cause cruise control to malfunction or brake lights to stay on.
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Tools You'll Need

How to Fix Error Code P0573

  1. Safety First

    Always disconnect the battery before working on electrical components.

  2. Locate the Brake Switch

  3. Inspect the Brake Switch

  4. Test the Brake Switch with a Multimeter

    Be careful not to damage the connector pins.

  5. Check for Short or Open in Wiring

    Do not probe wires with the ignition on unless instructed.

  6. Replace the Brake Switch if Faulty

  7. Check Fuses

    Never replace a blown fuse with a higher amperage fuse.

  8. Clear the Error Code and Test

    If the code returns, further diagnostics or professional help may be needed.

Parts You May Need

Brake light switch
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Fuse (brake lamp fuse)
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Brake light switch
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Fuse (brake lamp fuse)
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Brake light switch
Check Price on Amazon
Fuse (brake lamp fuse)
Check Price on Amazon
Brake light switch
Check Price on Amazon
Fuse (brake lamp fuse)
Check Price on Amazon
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When to Call a Professional

Call a mechanic if you've replaced the switch and wiring but the code returns, or if you're uncomfortable working under the dashboard near the brake pedal. Also seek professional help if the brake lights don't work at all or if the vehicle has other electrical issues.

Frequently Asked Questions

Can I drive with error code P0573?
You can drive short distances, but it's not recommended. The code can cause brake lights to stay on (draining battery) or not illuminate (safety hazard), and cruise control may not work. Have it checked as soon as possible.
Will a bad brake switch cause my battery to drain?
Yes, if the switch is stuck closed, the brake lights may stay on even when the car is off, draining the battery overnight.
Do I need to reprogram the brake switch after replacement?
Some vehicles require a brake pedal position sensor recalibration, but most aftermarket switches are plug-and-play. Check your service manual for specific procedures.
Can a faulty brake switch affect cruise control?
Yes, many cruise control systems disengage when the brake is pressed. A faulty switch may prevent cruise from engaging or cause it to drop out unexpectedly.
Is P0573 the same for all car brands?
Yes, P0573 is a generic OBD-II code meaning 'Brake Switch A Circuit High' across all makes and models. However, the exact location and testing procedure may vary slightly.

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