P0573
UniversalCruise Control/Brake Switch A Circuit High
The vehicle detected a signal that is higher than expected in the Cruise Control/Brake Switch A circuit. This switch signal helps the vehicle recognize brake-pedal operation and can affect cruise-control operation. The code identifies a circuit condition, not proof that the switch itself has failed.
⚠️ Before You Begin (Safety First)
Check that the brake lights turn on and off correctly before driving. If they do not work correctly, or stay on continuously, avoid driving until the problem is checked because other drivers may not be warned when you brake. Do not rely on cruise control until the issue is diagnosed.
Common Symptoms
- There may be no noticeable symptoms if the signal fault does not affect vehicle operation.
- Cruise control may be unavailable or may not respond as expected if the vehicle does not interpret the brake-switch signal correctly.
- Brake lights may stay on or fail to operate correctly, depending on the circuit design and fault.
- The code may appear with a warning light or message if the vehicle monitors or reports this fault.
Common Causes
- A brake-switch internal fault may cause its circuit signal to remain higher than expected.
- Damaged wiring or a short to a voltage source may raise the circuit signal.
- A loose, damaged, or corroded connector may interrupt or distort the signal.
- Incorrect switch adjustment or installation may prevent the circuit from changing state as intended.
- A fault in the circuit input or related control system may be involved; the code alone does not identify the failed part.
Diagnostic Steps
- With the vehicle parked safely, check whether the brake lights turn on when the pedal is pressed and turn off when it is released. Ask a helper to observe, or use a safe reflection; this checks for an obvious brake-light problem.
- Look for visible damage, loose connections, or corrosion around accessible brake-switch wiring and connectors. Do not force connectors or probe terminals.
- Note whether cruise control has stopped working or behaves differently, and whether other warning lights or codes are present. These details can help narrow diagnosis.
- If the brake lights work incorrectly, wiring damage is visible, or the code returns, have the vehicle tested using model-, year-, and engine-specific service information. Do not bypass the switch.
When to Call a Professional
A technician can compare brake-switch status with pedal operation using scan data, then inspect the circuit using the vehicle-specific wiring diagram and test procedures. Switch adjustment, connector condition, wiring faults, or an input-circuit problem may need to be distinguished before replacing parts.
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Commonly Asked Questions
Does P0573 prove the brake switch needs replacement?
No. It reports a high signal in the Cruise Control/Brake Switch A circuit. Wiring, connectors, adjustment, or the monitored input may also need checking.
Can I drive with P0573?
First check that the brake lights operate correctly. Avoid driving if they fail to illuminate or remain on, and do not use cruise control until the fault is diagnosed.
Why might cruise control stop working?
The system may use brake-switch status when deciding whether cruise control can operate or should cancel. A signal fault can therefore affect cruise-control behavior.
Can the code be present without obvious symptoms?
Yes. The vehicle may detect the circuit condition even when brake-light and cruise-control behavior seem normal.
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