C1890 DTC Code: Understanding and Resolving Common Issues

Introduction to C1890 DTC Code

The C1890 Diagnostic Trouble Code (DTC) is an error code that is commonly encountered in the automotive industry. This code represents a specific issue or malfunction within the vehicle’s electronic control system. Understanding what this code signifies is crucial for effectively diagnosing and resolving the underlying problem.

What Does the C1890 DTC Code Mean?

The C1890 DTC code refers to a fault in the electronic control system related to the ABS Hydraulic Pump Motor Control Circuit. This circuit is responsible for controlling the hydraulic pump motor that powers the Anti-lock Braking System (ABS). The ABS is a crucial safety feature in modern vehicles, which prevents the wheels from locking up during braking, ensuring optimal control and stability.

When the C1890 DTC code is triggered, it indicates a potential malfunction in the ABS Hydraulic Pump Motor Control Circuit. This may result in reduced or ineffective functionality of the ABS, compromising the vehicle’s braking performance and safety.

Common Causes of the C1890 DTC Code

Several factors can contribute to the triggering of the C1890 DTC code. Here are some of the most common causes:

  1. Faulty ABS Hydraulic Pump Motor: A malfunctioning or worn-out hydraulic pump motor can lead to the C1890 DTC code. Over time, these parts may experience mechanical wear or electrical failures, requiring replacement.

  2. Electrical Wiring and Connector Issues: Poor connections, loose or damaged wiring, or faulty connectors can disrupt the flow of electrical signals in the ABS Hydraulic Pump Motor Control Circuit, resulting in the C1890 DTC code.

  3. ABS Control Module Malfunction: The ABS control module is responsible for managing the overall operation of the ABS system. A malfunctioning control module can send incorrect signals to the hydraulic pump motor or fail to communicate with other components, leading to the C1890 DTC code.

  4. Sensor and Sensor Circuit Problems: The ABS system relies on various sensors, such as wheel speed sensors, to accurately detect wheel rotation and trigger the ABS when necessary. Faulty sensors or damaged sensor circuits can cause the C1890 DTC code.

Diagnosing and Resolving the C1890 DTC Code

Diagnosing and resolving the C1890 DTC code should be done by trained professionals with access to the appropriate diagnostic equipment. However, it can be helpful for vehicle owners to understand the potential steps involved in the process. Here is a general outline:

  1. Initial Inspection: The first step is to visually inspect the ABS system components, including the hydraulic pump motor, wiring, connectors, and control module. Any signs of physical damage or obvious defects should be noted.

  2. Diagnostic Scan Tool: A diagnostic scan tool is used to retrieve the specific DTCs stored in the vehicle’s onboard computer system. The C1890 DTC code should be recorded, and any other related codes should also be noted for a comprehensive diagnostic approach.

  3. Wiring and Connector Check: The integrity of the ABS Hydraulic Pump Motor Control Circuit wiring and connectors should be thoroughly examined. This involves inspecting for loose connections, damaged insulation, corrosion, or any other visible issues that may affect electrical continuity.

  4. Component Testing: Diagnostic tests should be performed on the ABS control module, hydraulic pump motor, and relevant sensors to assess their functionality. This may involve checking resistance, voltage levels, or performing specific procedures outlined in the manufacturer’s documentation.

  5. Repair or Replacement: Once the defective component or electrical issue is identified, appropriate repairs or replacements should be carried out. This could include replacing the ABS control module, hydraulic pump motor, wiring harness, connectors, or sensors, depending on the root cause of the C1890 DTC code.

Frequently Asked Questions (FAQs)

Q1: Can I continue driving my vehicle with the C1890 DTC code?

A1: It is not recommended to continue driving your vehicle when the C1890 DTC code is present. The ABS system is a crucial safety feature, and any malfunction can compromise your vehicle’s braking performance. It is best to have the issue inspected and repaired by a qualified technician.

Q2: Can a C1890 DTC code be triggered by a loose wheel bearing?

A2: While a loose wheel bearing can cause a variety of issues, it is unlikely to directly trigger the C1890 DTC code. However, a loose wheel bearing can lead to abnormal wheel speed readings, which may indirectly contribute to the triggering of the code.

Q3: How much does it cost to fix the C1890 DTC code?

A3: The cost of resolving the C1890 DTC code can vary depending on several factors, such as the specific component that needs repair or replacement, labor rates in your area, and whether new or used parts are utilized. It is best to consult with a trusted mechanic for an accurate estimate based on your vehicle’s make and model.

In conclusion, the C1890 DTC code indicates an issue with the ABS Hydraulic Pump Motor Control Circuit. Understanding the potential causes and necessary steps for diagnosis and repair can help ensure a prompt resolution. If you encounter this code, it is advisable to seek professional assistance to restore the functionality and safety of your vehicle’s ABS system.

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.


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