Park Brake Switch Failure
The parking brake switch is not functioning properly.
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)
Inside the system, the parking brake switch is supposed to send a signal (usually around 12V) to indicate if the brake is applied or released. If it fails, the computer doesn't know the brake status, which can trigger alarms or alter vehicle behavior.
What the computer is actually seeing
The control module detects an abnormal voltage or no voltage when the parking brake is engaged or disengaged. It expects a consistency in the signal tied to the position of the park brake—generally 0V when off and 12V when on.
What a healthy reading looks like
Expected voltage readings from the brake switch are around 0V (off) or 12V (on).
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 parking brake switch and connector for damage or corrosion. Decision Point: If damaged, repair or replace.
- 22. Check for proper voltage at the parking brake switch - should read 0V (switch off) and 12V (switch on). Decision Point: If voltage is incorrect, trace wiring back to the control module.
- 33. If wiring is intact, test the control module for fault codes or failure. Decision Point: If control module is faulty, consider replacement.
Common causes
- Faulty parking brake switch
- Wiring issues to the switch
- Bad connector or corrosion
- Faulty control module
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to fix it soon as it can affect braking safety indicators.
Will this code come back after clearing?
Yes, if the underlying issue isn't fixed, it will return.
Why does it pair with SPN 3741?
SPN 3741 relates to pressure switch malfunction, which often happens alongside park brake issues.
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