C1187 DTC Code: Understanding and Troubleshooting


C1187 is a Diagnostic Trouble Code (DTC) that is commonly found in vehicles equipped with On-Board Diagnostics II (OBD-II) systems. This code corresponds to a problem within the ABS Pump Motor Control Circuit.

In this article, we will delve deep into the C1187 DTC code, exploring its meaning, common causes, diagnostic procedures, and possible solutions. By the end, you will have a comprehensive understanding of this specific DTC and be equipped with the knowledge to effectively troubleshoot it.

Understanding the C1187 DTC Code

What is a DTC code?

DTC codes are generated by the OBD-II system whenever a fault is detected within the vehicle’s system. These codes help technicians identify the root cause of the problem and facilitate the troubleshooting process. Each DTC code consists of five characters, with the first character being a letter, followed by four numbers, such as C1187.

What does the C1187 code indicate?

The C1187 DTC code specifically points to an issue in the ABS Pump Motor Control Circuit. This circuit is responsible for controlling the operation of the ABS pump motor, which plays a crucial role in the vehicle’s braking system. When this code is present, it indicates a malfunction within this circuit, requiring attention and repair.

Common Causes of the C1187 DTC Code

To effectively troubleshoot the C1187 DTC code, it is important to understand its common causes. Here are some factors that can lead to the appearance of this code:

  1. Faulty ABS Pump Motor: A defective ABS pump motor can trigger the C1187 code. Over time, the motor may wear out, develop internal faults, or experience electrical issues, impacting its proper functioning.
  2. Wiring Issues: Damaged or shorted wiring within the ABS Pump Motor Control Circuit can result in the code’s appearance. Frayed wires, loose connections, or corroded terminals can disrupt the electrical signal, leading to the malfunction.
  3. Faulty ABS Control Module: In some cases, the ABS control module itself may be at fault. Malfunctioning internal components or a software glitch within the module can trigger the C1187 code.

Diagnostic Procedures for C1187 DTC Code

To diagnose and troubleshoot the C1187 DTC code, follow these step-by-step procedures:

Step 1: Inspection

Begin by visually inspecting the ABS Pump Motor Control Circuit and related components. Look for any visible signs of damage, such as frayed wires or loose connections. Pay close attention to the ABS pump motor and its connectors.

Step 2: Scan the Vehicle

Connect an OBD-II scanner to the vehicle’s diagnostic port and retrieve all stored codes, including the C1187 code. This step will provide you with valuable information regarding the specific issue at hand.

Step 3: Test the ABS Pump Motor

Utilize a multimeter to test the ABS pump motor for proper voltage and continuity. Refer to the vehicle’s repair manual for the specific testing procedure and acceptable ranges. If any abnormalities are detected, the ABS pump motor may require repair or replacement.

Step 4: Inspect the Wiring

Thoroughly inspect the wiring within the ABS Pump Motor Control Circuit. Check for any signs of damage, including frayed wires, loose connections, or corrosion. Repair or replace any damaged wiring as necessary.

Step 5: Test the ABS Control Module

If all other components check out, the ABS control module itself may be the culprit. Test the module using specialized diagnostic equipment designed for this purpose. If a fault is detected, consider seeking professional assistance or replacing the module.

Frequently Asked Questions (FAQs)

Q1: Can I continue driving my vehicle with the C1187 DTC code?

A1: It is generally not recommended to drive your vehicle when a DTC code like C1187 is present. This code indicates a fault within the ABS Pump Motor Control Circuit, which directly affects your braking system’s performance and safety. It is crucial to resolve the issue before continuing to drive the vehicle.

Q2: Can I fix the C1187 DTC code myself?

A2: While some DIY enthusiasts may be able to troubleshoot and resolve the C1187 code on their own, it is recommended to have a professional technician or a certified mechanic handle the repair. These professionals possess the necessary knowledge, skills, and equipment to accurately diagnose and fix the issue, ensuring a proper and safe resolution.

Q3: How much does it cost to repair the C1187 DTC code?

A3: The cost of repairing the C1187 code can vary depending on several factors such as the specific cause, the vehicle make and model, and the labor rates in your area. It is best to consult with a trusted mechanic or repair shop to obtain an accurate estimate for your particular situation.


The C1187 DTC code indicates a problem within the ABS Pump Motor Control Circuit. Understanding the meaning, common causes, diagnostic procedures, and potential solutions associated with this code empowers vehicle owners and technicians to effectively address this issue. Remember, it is important to prioritize safety and seek professional assistance when necessary for a successful repair.

About author


Meet Sam Mitchell, your experienced and reliable guide in the complex world of car fault codes. With a robust career spanning over 15 years as a professional car mechanic, John has the skills, knowledge, and practical experience to help you navigate car fault issues with confidence.


Leave a Reply