Brake Pressure Switch A Circuit Range/Performance Problem
The brake pressure switch circuit is having performance issues.
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What it means (plain English)
The brake pressure switch detects how hard you're pressing on the brake pedal. It should send a signal to the computer based on that pressure, but it’s either reading too low or too high when it shouldn’t.
What the computer is actually seeing
The computer monitors the voltage signal from the brake pressure switch; if the voltage is outside of the expected range during braking events (0.5V to 4.5V), it triggers a fault.
What a healthy reading looks like
Expected voltage signal from brake pressure switch should be between 0.5V (no pressure) and 4.5V (full pressure).
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 wiring and connectors for damage or corrosion around the brake pressure switch. Repair or replace as needed. DECIDE: If wiring is damaged, FIX IT. If not, move to step 2.
- 22. Check the brake fluid level. Ensure it’s at the proper level. DECIDE: If low, top it off and recheck for codes. If level is okay, move to step 3.
- 33. Use a multimeter to test the brake pressure switch signal voltage while applying brake pressure. It should vary from 0.5V to 4.5V. DECIDE: If voltages are within range, see if the issue is with the PCM; if out of range, replace the brake pressure switch.
Common causes
- Faulty brake pressure switch
- Damaged wiring or connectors
- Brake fluid leaks affecting pressure
- Faulty brake module or PCM
Typical repair cost
$$$ (approximately $150-$300)
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive, but you may have inconsistent brake performance, so fix it soon.
Will this problem come back after I fix it?
If the underlying issue causing the incorrect signals is resolved (like wiring or the switch itself), then it should not return.
Why does this code appear with other brake-related codes?
It can share triggers like faulty switches or low fluid levels, which affect multiple brake system signals.
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