B1659 DTC Code: A Comprehensive Guide


In the world of automotive diagnostics, DTC codes play a crucial role in identifying and resolving issues with vehicles. One such code is the B1659 DTC code. In this article, we will delve deep into the specifics of the B1659 code, its meaning, causes, symptoms, and potential solutions.

Understanding the B1659 DTC Code

The B1659 code is a diagnostic trouble code related to the vehicle’s body control module (BCM). It is specific to certain vehicle makes and models and may vary in its meaning across different manufacturers. To determine the exact interpretation of the code, it is essential to consult the vehicle’s service manual or reach out to a certified mechanic.

Common Causes of the B1659 DTC Code

  1. Faulty Door Ajar Switch: One of the primary causes of the B1659 code is a malfunctioning door ajar switch. This switch, located in the door latch mechanism, is responsible for detecting whether a specific door is open or closed. A faulty switch can trigger the B1659 code and lead to related issues.

  2. Wiring or Electrical Issues: Damaged or shorted wiring, as well as other electrical problems, can also trigger the B1659 code. If there is a break in the wiring harness or a loose connection, it can disrupt the communication between the body control module and the door ajar switch.

  3. Defective Body Control Module: In some cases, a defective body control module itself can be the root cause of the B1659 code. The body control module is responsible for controlling various electrical systems within the vehicle, including door locks and interior lights. A malfunctioning module can send erroneous signals and trigger the code.

Symptoms of the B1659 DTC Code

When the B1659 code is triggered, the vehicle may exhibit one or more of the following symptoms:

  • Illuminated Malfunction Indicator Lamp (MIL): The check engine light or the MIL may be lit up on the vehicle’s dashboard, indicating the presence of a fault.

  • Door-Related Issues: The B1659 code can lead to problems with the vehicle’s doors, such as inaccurate door status readings or the inability to lock/unlock doors using the remote keyless entry system.

  • Interior Light Malfunction: A malfunctioning body control module can result in erratic behavior of the interior lights, such as lights staying on when they should be off or vice versa.

Resolving the B1659 DTC Code

Diagnosing and resolving the B1659 code often requires specialized knowledge and diagnostic tools. It is recommended to consult a professional mechanic or authorized service center for accurate diagnosis and repairs. However, below are a few general steps that can be taken to address the issue:

  1. Inspect Door Ajar Switches: Begin by inspecting the door ajar switches for any signs of damage or misalignment. If any issues are found, the faulty switch should be replaced with a new one compatible with the vehicle make and model.

  2. Check Wiring Connections: Carefully examine the wiring connections between the door ajar switch and the body control module. Ensure that all wires are properly connected, undamaged, and free from corrosion. Repair or replace any damaged wiring as necessary.

  3. Test the Body Control Module: If all the above steps fail to resolve the issue, it may be necessary to test the body control module itself. This requires specialized diagnostic equipment and technical expertise. If a faulty module is detected, it must be replaced with a new one from the vehicle manufacturer.

Frequently Asked Questions (FAQs)

Q1: Can I drive my vehicle with the B1659 DTC code?

A1: As long as the vehicle continues to operate normally and there are no significant symptoms affecting its performance or safety, it is generally safe to drive the vehicle. However, it is advisable to get the issue diagnosed and resolved at the earliest opportunity to prevent potential complications.

Q2: Can I reset the B1659 code by disconnecting the battery?

A2: While disconnecting the battery can clear some DTC codes, it is not recommended for resolving the B1659 code. This code is related to a specific issue that requires proper diagnosis and repair. Disconnecting the battery may temporarily clear the code, but it is likely to reappear until the underlying problem is addressed.

Q3: How much does it cost to fix the B1659 DTC code?

A3: The cost of fixing the B1659 code can vary depending on various factors such as the vehicle make and model, the cause of the code, and labor costs. It is best to consult with a professional mechanic or authorized service center for an accurate estimate based on your specific vehicle’s requirements.


The B1659 DTC code can be a cause of concern for vehicle owners. However, with a proper understanding of its meaning, causes, symptoms, and potential solutions, it becomes easier to address the issue effectively. It is crucial to obtain accurate diagnosis and professional assistance for resolving the B1659 code to ensure the safe and reliable operation of your vehicle.

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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