Active Braking System Malfunction
This indicates a fault in the active braking system operation.
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 computer sees that the braking system isn't responding as it should, which could lead to reduced braking ability or a complete loss of braking, creating a safety risk.
What the computer is actually seeing
The vehicle's computer detects an internal fault or a malfunction in the active braking system modules or sensors.
What a healthy reading looks like
Expected voltage readings for braking sensors should be between 0.5V and 4.5V during operation. System pressures should be maintained around 1200-2000 PSI depending on the vehicle.
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; should be at the full mark. If low, refill and recheck for codes.
- 22. Inspect wiring and connectors for any signs of damage or corrosion related to the brake control module; repair as necessary.
- 33. Use a scan tool to check for additional codes related to the brake system; address those issues first.
- 44. Monitor voltage at the brake control module; should see between 0.5V to 4.5V. If outside this range, further diagnostic on the module may be necessary.
- 55. Inspect wheel speed sensors; should read at least 1V while wheel is spinning. Replace any faulty sensors.
Common causes
- Faulty brake control module
- Corroded or damaged wiring/connectors
- Low brake fluid level
- Faulty wheel speed sensors
- Software issues in the braking system
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, this code indicates a serious braking system issue that could lead to brake failure. Do not drive until it is repaired.
Will this code come back after I clear it?
If the underlying issue is not fixed, it will likely return after clearing.
Why does this code sometimes pair with C1311?
C1311 often indicates a related issue in the brake control circuit, so it's common to see them together.
Working a real vehicle right now?
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