P0573: Brake Switch High Input

Definition

The OBD2 code P0573 indicates that the brake switch signal is reading a high voltage input, which may suggest a malfunction in the brake switch or its circuit

Common causes

Faulty brake light switch
Short circuit in the brake switch circuit
Open circuit in the brake switch circuit
Corroded or damaged wiring/connectors
Malfunctioning brake pedal position sensor
Faulty engine control module (ECM) or powertrain control module (PCM)

Common misdiagnoses

Faulty brake switch
Wiring issues or shorts in the brake switch circuit
Malfunctioning cruise control system
Faulty engine control module (ECM)
Issues with the anti-lock braking system (ABS)
Problems with the transmission range sensor
Faulty accelerator pedal position sensor

Troubleshooting steps

1. Check the Brake Light Switch
2. Inspect the brake light switch for proper operation. The switch is usually located near the brake pedal
3. Ensure that the switch is not stuck in the "on" position, which could cause a high input signal
4. Inspect Wiring and Connectors
5. Check the wiring and connectors leading to the brake light switch for any signs of damage, corrosion, or loose connections
6. Look for any frayed wires or shorts that could be causing an incorrect signal
7. Test the Brake Light Switch
8. Use a multimeter to test the brake light switch. It should show continuity when the brake pedal is pressed and no continuity when it is released
9. If the switch is faulty, replace it
10. Check Brake Lights
11. Ensure that the brake lights are functioning correctly. If the brake lights are always on, it may indicate a problem with the switch or wiring
12. Replace any burnt-out bulbs or fix any issues with the brake light circuit
13. Inspect the ECM/TCM
14. In some cases, the issue may be related to the engine control module or transmission control module. Check for any software updates or known issues with the modules
15. If necessary, perform a reset or reprogramming of the ECM/TCM
16. Scan for Additional Codes
17. Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide additional context for the issue
18. Clear the Code and Test Drive
19. After addressing any issues found, clear the trouble code using an OBD-II scanner
20. Take the vehicle for a test drive to see if the code returns. If it does, further investigation may be needed
21. Consult a Professional
22. If the problem persists after performing these steps, it may be best to consult a professional mechanic for a more in-depth diagnosis. By following these steps, you should be able to identify and resolve the issue related to the P0573 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check the Brake Light Switch

2. Inspect the brake light switch for proper operation. The switch is usually located near the brake pedal

3. Ensure that the switch is not stuck in the "on" position, which could cause a high input signal

4. Inspect Wiring and Connectors

5. Check the wiring and connectors leading to the brake light switch for any signs of damage, corrosion, or loose connections

6. Look for any frayed wires or shorts that could be causing an incorrect signal

7. Test the Brake Light Switch

8. Use a multimeter to test the brake light switch. It should show continuity when the brake pedal is pressed and no continuity when it is released

9. If the switch is faulty, replace it

10. Check Brake Lights

11. Ensure that the brake lights are functioning correctly. If the brake lights are always on, it may indicate a problem with the switch or wiring

12. Replace any burnt-out bulbs or fix any issues with the brake light circuit

13. Inspect the ECM/TCM

14. In some cases, the issue may be related to the engine control module or transmission control module. Check for any software updates or known issues with the modules

15. If necessary, perform a reset or reprogramming of the ECM/TCM

16. Scan for Additional Codes

17. Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide additional context for the issue

18. Clear the Code and Test Drive

19. After addressing any issues found, clear the trouble code using an OBD-II scanner

20. Take the vehicle for a test drive to see if the code returns. If it does, further investigation may be needed

21. Consult a Professional

22. If the problem persists after performing these steps, it may be best to consult a professional mechanic for a more in-depth diagnosis. By following these steps, you should be able to identify and resolve the issue related to the P0573 code