Brake Switch Input Circuit Failure
The brake switch signal is incorrect or missing.
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, which tells the system when you press the brake, isn't working right. This could be because the switch is faulty or there's a wiring issue.
What the computer is actually seeing
The computer expects a closed circuit (signal) when the brake is pressed. If it sees an open circuit or an unexpected voltage level (e.g., close to battery voltage instead of ground), it sets this code.
What a healthy reading looks like
Brake switch should show a voltage drop close to 0V when pressed and around 12V when 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.
- 11. Check the brake fluid level; ensure it's above the minimum level and not affecting the brake system.
- 22. Inspect wiring and connectors going to the brake switch for damage or corrosion; ensure they are clean and tight.
- 33. Measure voltage at the brake switch connector: should be around 12V when brake is released and near 0V when pressed. If incorrect, continue troubleshooting.
- 44. If voltage tests are correct but code persists, replace the brake switch and clear codes.
Common causes
- Faulty brake switch
- Wiring issues or shorts in the brake switch circuit
- Connector corrosion or damage
- ABS module faults
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best not to drive until the brake system is verified; brake performance may be affected.
Will this code come back?
If the underlying issue isn't fixed, yes, it'll likely return after clearing.
Why does this code pair with others?
Codes often indicate related systems; for instance, if the brake signal is faulty, it can affect traction control or stability systems.
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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