Brake Switch Circuit
Indicates a problem in the brake switch circuit.
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 computer when you press the brake pedal. If this signal is lost or wrong, it can cause the engine to behave unexpectedly or affect the braking system.
What the computer is actually seeing
The computer expects a certain voltage when the brake pedal is pressed (usually around 0.5 to 0.8 volts when off, and close to 12 volts when pressed).
What a healthy reading looks like
0.5V - 0.8V (off), close to 12V (on) when brake pedal is 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.
- 1Check the brake switch for physical damage or wear. Is it stuck or broken?
- 2Inspect wiring and connectors at the brake switch: Look for frays, shorts, or corrosion. Are they intact?
- 3Using a multimeter, check the voltage at the brake switch connector with the key on. Are you getting 0.5 to 0.8 volts when the pedal is not pressed?
- 4If the voltage is incorrect or intermittent, replace the brake switch and retest. If it's good, move to the engine control module connectivity.
- 5Test the connectivity of the wiring between the brake switch and the ECM/PCM. Is there continuity?
- 6If there's no continuity, repair the wire or connectors as needed. If continuity is present but the code persists, suspect the ECM may be damaged.
Common causes
- Bad brake switch
- Wiring issues
- Corroded connectors
- Faulty computer system
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity indicates potential safety issues, especially with the braking system. Fix it soon.
Will this code come back after I clear it?
If the underlying issue isn't resolved, the code is likely to return.
Why does this code sometimes pair with other SPNs?
Several faults in the brake system can trigger multiple codes; they share circuits or components.
Working a real vehicle right now?
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