Brake Switch A Circuit Stuck Open
The brake pedal position switch circuit is reading as open when closed.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
When you press the brake pedal, a switch should close and send a signal to the vehicle’s computer. If the switch is stuck open, the computer thinks the brake isn't being applied when it actually is.
What the computer is actually seeing
The brake switch should output a voltage signal when the pedal is pressed. If it stays at 0 volts even when pressed, the computer registers a fault.
What a healthy reading looks like
Expected voltage at the brake switch should be between 0.1 - 0.5 volts (open circuit) and close to battery voltage (typically 12-14 volts) when pressed.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the brake switch wiring and connectors for damage or corrosion. If any issues are found, repair or replace as needed. Decision: Did repairs fix the issue?
- 22. Test the voltage at the brake switch with the pedal pressed. It should read close to battery voltage. Decision: Is the voltage correct?
- 33. If the voltage is not correct, replace the brake switch. Decision: Did replacing the switch fix the code?
- 44. If the problem persists, check wiring continuity back to the ECM. Decision: Is the wiring intact?
Common causes
- Faulty brake switch
- Wiring damage or corrosion
- Connector issues at the switch
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not safe since the brake light may not function properly, affecting visibility and safety.
Will this code come back after clearing?
If the root cause isn't fixed, it will likely reappear.
How does this code affect braking performance?
The vehicle may not recognize when the brakes are applied, impacting systems like cruise control and stability.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →