Brake Fluid Level Sensor Circuit Low
The brake fluid level sensor is detecting a low fluid condition.
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What it means (plain English)
The brake fluid level sensor is sending a low voltage signal, indicating that the brake fluid level is below the proper range, which can affect the braking system's performance.
What the computer is actually seeing
The brake fluid level sensor sends a variable voltage to the ABS module; low fluid levels may cause the voltage to drop below 0.5 volts, prompting the C1187 code to trigger.
What a healthy reading looks like
Expected voltage from the brake fluid level sensor should be between 0.5 to 4.5 volts depending on fluid level; low fluid level usually results in voltage below 0.5 volts.
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.
- 1Inspect brake fluid reservoir for proper fluid level; add fluid if low.
- 2Check for any visible leaks in the brake system that may affect fluid level.
- 3Test the voltage at the brake fluid level sensor connector with the key on (engine off); expect between 0.5 and 4.5 volts.
- 4Inspect wiring and connector at the brake fluid level sensor for damage or corrosion; repair as needed.
- 5If fluid level is good, and voltage is correct, replace the brake fluid level sensor.
Common causes
- Low brake fluid level in the reservoir
- Faulty brake fluid level sensor
- Corroded or damaged wiring/connectors to the sensor
- Fluid leak in the brake system
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive with low brake fluid as it directly affects the braking capability, increasing safety risks.
Will the code come back?
Yes, if the underlying issue, like low fluid or a faulty sensor, isn't fixed.
Why does this code appear when the brake system appears to be functioning?
The system monitors fluid levels closely; any drop can trigger the code, even if immediate performance seems okay.
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