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DTC codes / C05xx · Brakes, steering and suspension / C0573

C0573Electric Park Brake Switch Circuit Malfunction

C0573 means the electronic control unit that manages the electric parking brake has detected an electrical fault in the switch circuit, such as an open, short, or implausible signal. The computer monitors the switch voltage and compares it to expected values; when the reading falls outside the valid range for a set time, it stores this code and typically disables the electric park brake function.

SystemChassis
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaBrakes, steering and suspension

Symptoms you may notice

  • The red brake warning light or a yellow parking brake warning light stays illuminated on the dashboard.
  • The electric parking brake may fail to engage or release when you press the switch, leaving the vehicle stuck or without parking brake hold.
  • A message such as 'Parking Brake Fault' or 'Service Parking Brake' appears in the driver information display.
  • The parking brake may engage automatically but refuse to release, or release automatically but fail to engage.
  • Often no symptoms besides the warning light, with the brake continuing to operate normally in some cases.
  • The switch may feel loose, sticky, or unresponsive, or require multiple presses to trigger the brake.

Common causes, most likely first

  1. A faulty electric parking brake switch that has worn contacts or internal failure.
  2. Damaged or corroded wiring between the switch and the electronic parking brake control module, often from flexing at the switch connector.
  3. A loose, disconnected, or corroded electrical connector at the switch or at the control module.
  4. Water intrusion into the switch assembly or connector, causing intermittent shorts or opens.
  5. A failed electronic parking brake control module that cannot correctly read the switch input.
  6. Blown fuse or poor ground connection serving the switch circuit.
  7. Aftermarket accessories or previous repairs that tapped into the switch wiring and disturbed the circuit.

How to diagnose and fix it

  1. Verify the battery voltage and check the fuse that supplies the electric parking brake switch circuit.
  2. Inspect the switch connector and the control module connector for corrosion, loose pins, or water intrusion, and clean or reseat as needed.
  3. Perform a resistance and voltage drop test on the switch circuit wiring while wiggling the harness to reveal intermittent faults.
  4. Test the switch itself with a multimeter for continuity in both engaged and released positions, comparing to the manufacturer's specification.
  5. Use a scan tool to read live data from the parking brake switch and confirm whether the control module sees the correct switch states.
  6. If the switch tests bad, replace it and clear the code; if the wiring tests bad, repair the affected section and recheck.
  7. If the switch and wiring are good, follow the manufacturer's diagnostic flow for the control module, which may require module replacement or reprogramming.

What the switch circuit code hides

  • A weak or failing battery can cause this code because the control module may misread switch voltage during cranking or low-voltage events, so always load-test the battery before condemning the switch.
  • The switch is often a simple momentary contact, but some systems use a resistor ladder or multiplexed signal, so a generic continuity test can pass while the switch still sends an invalid signal to the module.
  • Water intrusion from a clogged sunroof drain or a poorly sealed connector can corrode the switch circuit and set C0573 intermittently, especially after rain or a car wash.
  • The code can be stored by a momentary glitch that has already cleared, so clearing the code and test-driving may show it does not return, saving an unnecessary switch replacement.
  • A misadjusted or sticking parking brake mechanism can cause the module to flag the switch circuit because the module expects a certain response time and sees an implausible sequence.

Can I keep driving with C0573?

You can usually drive the vehicle, but the electric parking brake may not engage or release reliably, so avoid parking on steep hills and do not rely on the parking brake to hold the car. If the brake is stuck engaged, do not force the vehicle to move; have it serviced or manually released according to the owner's manual procedure.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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