C1187 – OBD-II DTC

OBD-II DTC C1187 – Brake Fluid Level Sensor Input Open Circuit

DTC C1187 meaning

DTC C1187 refers to a diagnostic trouble code indicating an open circuit in the brake fluid level sensor input. This code is triggered when the vehicle’s onboard diagnostics system detects that the signal from the brake fluid level sensor is not reaching the control module, suggesting a potential issue with the sensor or its wiring.

DTC C1187 symptoms

Common symptoms associated with DTC C1187 may include:

• Illuminated brake warning light on the dashboard
• Inconsistent or erratic brake fluid level readings
• Potential loss of brake assist or reduced braking performance
• Increased risk of brake system failure if not addressed

DTC C1187 causes

Several factors can lead to the triggering of DTC C1187, including:

• Faulty brake fluid level sensor
• Damaged or corroded wiring or connectors in the sensor circuit
• Low brake fluid level due to leaks or evaporation
• Issues with the vehicle’s control module

DTC C1187 seriousness

DTC C1187 is considered a serious issue as it relates to the brake system. If the brake fluid level sensor is malfunctioning, it may lead to undetected low brake fluid levels, increasing the risk of brake failure. It is crucial to address this code promptly to ensure safe vehicle operation.

How to diagnose DTC C1187

To diagnose DTC C1187, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the C1187 code.
2. Inspect the brake fluid level and ensure it is at the recommended level.
3. Check the wiring and connectors leading to the brake fluid level sensor for damage or corrosion.
4. Test the brake fluid level sensor for proper operation using a multimeter.
5. Examine the vehicle’s control module for any related fault codes or issues.

How to fix DTC C1187 step-by-step instructions

To fix DTC C1187, follow these steps:

1. Ensure the brake fluid level is adequate top off if necessary.
2. Inspect and repair any damaged wiring or connectors in the sensor circuit.
3. If the brake fluid level sensor is faulty, replace it with a new one.
4. Clear the DTC using an OBD-II scanner after repairs are made.
5. Test drive the vehicle to ensure the code does not reappear and the brake system functions correctly.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.