Brake Switch Circuit Range / Performance Problem
There's a problem with the brake switch signal to the ECM.
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)
The brake switch sends a signal to the engine control module (ECM) when you press the brake pedal, but it's not sending the right signal.
What the computer is actually seeing
The ECM expects a voltage change when the brake pedal is pressed. Normally, when pressed, the switch should close, pulling the voltage down to near 0V (ground) for a closed signal, and it expects a range near the battery voltage (around 12V) when released.
What a healthy reading looks like
Brake switch signal should be 0V when engaged (brake pressed), and close to 12V when disengaged (brake released).
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.
- 1Inspect the brake switch wiring and connectors for damage or corrosion. If you find issues, repair as needed, and retest. Decision Point: Is the wiring and connector in good condition? Yes: Move to step 2; No: Repair wiring/connectors.
Common causes
- Faulty brake switch
- Wiring issues (chafing, corrosion)
- Loose or damaged connector at the brake switch
- Additional load on the circuit (like aftermarket accessories)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can still drive but fixing it soon is recommended to avoid potential brake system issues.
Will the code come back if I clear it?
If the underlying issue isn't fixed, yes, it will likely trigger again.
Why does it pair with other codes?
Brake switch issues can affect multiple systems like traction control, cruise control, and ABS, leading to multiple related codes.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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