Harley Davidson BCM Problems: Common Issues and Solutions

Harley Davidson motorcycles are known for their powerful engines and unique designs. However, even the most reliable machines can experience issues with their electronic components, including the Body Control Module (BCM). The BCM is responsible for controlling various functions of the motorcycle, such as lighting, turn signals, and security systems. When the BCM malfunctions, it can cause a range of problems that affect the performance and safety of the motorcycle.

Some common Harley Davidson BCM problems include difficulty starting the engine, engine cutting out while riding, and malfunctioning turn signals or lighting. These issues can be caused by a range of factors, including faulty wiring, damaged sensors, or a malfunctioning BCM. In some cases, the BCM may need to be replaced or reprogrammed to resolve the issue. It is important to address these problems promptly to ensure the safety and reliability of the motorcycle.

If you are experiencing issues with your Harley Davidson motorcycle, it is important to seek the help of a qualified technician who is familiar with the specific model and its electronic components. They can diagnose the problem and recommend the appropriate course of action, whether it is repairing the existing BCM or replacing it with a new one. With proper maintenance and attention, your Harley Davidson motorcycle can provide years of reliable performance and enjoyment. So where do we start then?

Table of Contents

Overview of The BCM in Harley Davidsons

Example of a Harley Body Control Module (BCM) that has been removed from a bike due to ongoing issues

Role of the BCM

The Body Control Module, commonly known as the BCM, is a crucial component in Harley Davidson motorcycles. It serves as a central hub for controlling various electrical systems and accessories in the bike. From managing the lights and indicators to monitoring the engine’s performance, the BCM plays a vital role in ensuring the smooth operation of the motorcycle. The BCM is responsible for communicating with the Electronic Control Unit (ECU) and other modules to control and monitor the bike’s various systems.

BCM vs ECU

The ECU is responsible for controlling the engine’s performance, while the BCM is responsible for controlling the electrical systems and accessories. The ECU and BCM communicate with each other through a Controller Area Network (CAN) bus. The ECU sends information about the engine’s performance to the BCM, which then controls the electrical systems and accessories based on that information.

In summary, the BCM is a crucial component in Harley Davidson motorcycles, responsible for controlling various electrical systems and accessories in the bike. It communicates with the ECU and other modules to control and monitor the bike’s various systems. The ECU, on the other hand, is responsible for controlling the engine’s performance. The BCM and ECU communicate with each other through a Controller Area Network (CAN) bus.

Common BCM Issues and Diagnostic Codes

Harley Davidson BCM (Body Control Module) is a crucial component that controls various electrical systems such as lighting, turn signals, and ignition. However, like any other electrical component, it is prone to issues that can affect its performance. In this section, we’ll discuss some of the common BCM issues and diagnostic codes that can help you identify and troubleshoot the problems.

Electrical Problems and Battery Issues

One of the most common issues with the BCM is related to electrical problems and battery issues. A low battery voltage can cause various BCM issues, including lighting problems, turn signal issues, and ignition problems. Therefore, it’s essential to check the battery voltage regularly and replace it if necessary.

DTC and Error Codes

Another common issue with the BCM is related to Diagnostic Trouble Codes (DTC) and error codes. DTC codes are stored in the BCM memory when there is an issue with the system, and they can help you identify the problem. Here are some of the most common DTC codes related to the BCM:

B1103: Front turn signal output fault
B1151: Sidecar BAS low/open
B1153: Sidecar BAS high/short to power

B1200: Fuel sender open/high

If you encounter any of these DTC codes, it’s essential to diagnose and fix the issue promptly. You can use a diagnostic tool to read the DTC codes and troubleshoot the problem.

The BCM is a crucial component in your Harley Davidson motorcycle, and it’s essential to keep it in good working condition. By understanding the common BCM issues and diagnostic codes, and how to clear them when necessary, you can diagnose and troubleshoot the problems effectively.

Troubleshooting and Repairing BCM Problems

Body Control Module (BCM) problems are common in Harley Davidson motorcycles. If you’re experiencing issues with your BCM, there are a few things you can do to troubleshoot the problem and repair it. In this section, we’ll go over step-by-step troubleshooting and BCM replacement.

Step-by-Step Troubleshooting Guide

A Fluke Multimeter that I use to diagnose error codes and BCM problems on my Harley Davidsons

If you’re experiencing issues with your BCM, follow these steps to troubleshoot the problem:

Check the battery voltage: A low battery voltage can cause BCM problems. Check the battery voltage and make sure it’s at least 12.5 volts.
Check the fuses: Check the fuses for the BCM and make sure they’re not blown.

Check the connections: Check the connections to the BCM and make sure they’re clean and tight.
Check for error codes: Use a diagnostic tool to check for error codes stored in the BCM. This will help identify the problem.
Check the wiring: Check the wiring to the BCM and make sure it’s not damaged or corroded.

Check the BCM: If all else fails, the BCM may need to be replaced.

BCM Replacement and Part Numbers

If you need to replace your BCM, here are the steps to follow:

Purchase the correct BCM: Make sure you purchase the correct BCM for your Harley Davidson motorcycle. The part number can be found in your owner’s manual or by contacting a Harley Davidson dealer.

Install the BCM: Remove the old BCM and install the new one. Make sure all connections are clean and tight.
Program the BCM: If the new BCM needs to be programmed, follow the instructions in your owner’s manual or contact a Harley Davidson dealer.
Test the BCM: Once the new BCM is installed and programmed, test it to make sure it’s working properly.

By following these steps, you can troubleshoot and repair BCM problems in your Harley Davidson motorcycle. If you’re unsure about any of these steps, contact a professional or a Harley Davidson dealer for assistance.

BCM-Related Electrical Components

Harley Davidson motorcycles use a Body Control Module (BCM) to manage various electrical components of the bike. These components include lighting, security system, and antenna output. The BCM is responsible for communicating with other modules and components to ensure that the bike runs smoothly. However, there are some issues that may arise with these components.

Lighting and Output Issues

One common issue that riders may experience is lighting and output issues. This can include problems with the Acc Output Shorted High, Acc Output Shorted Low, Acc Output Overloaded, and other related issues. If the BCM detects any of these issues, it may cause the bike to shut down or prevent it from starting altogether. Riders may also experience flickering or dimming lights, which can be a sign of a failing BCM.

Security System and Antenna Output

Another issue that riders may encounter is with the security system and antenna output. The BCM is responsible for communicating with the security system and antenna output, which can cause problems if there are any issues with these components. Riders may experience problems with the Security Antenna Output Open, Security Antenna Output Shorted High, Security Antenna Output Shorted Low, and other related issues. If the BCM detects any of these problems, it may cause the security system to malfunction, preventing the bike from starting or shutting it down while riding.

In summary, the BCM is responsible for managing various electrical components of the Harley Davidson motorcycle. Riders may experience issues with lighting and output, security system, and antenna output. If any of these issues arise, it is important to have the bike inspected by a professional to diagnose and repair the problem.

Maintaining Your Harley’s BCM

Regular maintenance of your Harley’s Body Control Module (BCM) is crucial for ensuring the smooth operation of your motorcycle’s electrical systems. Here are some tips to help you maintain your BCM:

Regular BCM Checks

Regular checks of your BCM can help you detect any issues before they become major problems. You can check your BCM by using a diagnostic tool to scan for any error codes. If you find any error codes, you can refer to your motorcycle’s owner’s manual to determine the cause of the problem and how to fix it.

Preventative Measures

Preventative measures can help you avoid BCM problems altogether. Here are some tips to help you prevent BCM problems:

Keep your motorcycle’s battery in good condition. A weak or dying battery can cause BCM problems.

Check your motorcycle’s wiring regularly. Loose or damaged wiring can cause BCM problems.
Keep your motorcycle’s ignition switch clean and free of debris. A dirty or damaged ignition switch can cause BCM problems.
Avoid exposing your motorcycle to extreme temperatures. Extreme temperatures can cause BCM problems.

By following these tips, you can help ensure that your Harley’s BCM is in good condition and that your motorcycle’s electrical systems are working properly. If you do experience any BCM problems, be sure to consult your motorcycle’s owner’s manual or a qualified mechanic for assistance.

Frequently Asked Questions

What are the common indicators of a malfunctioning Body Control Module on a Harley Davidson?

The most common indicators of a malfunctioning Body Control Module (BCM) on a Harley Davidson motorcycle are the illumination of the red alarm light on the dash, difficulty in starting the bike, and failure of the lights and indicators to work properly. A malfunctioning BCM can also cause issues with the engine’s performance and other electrical systems.

How does one perform a reset on the Body Control Module of a Harley Davidson?

To reset the Body Control Module (BCM) of a Harley Davidson, one needs to press and hold the trip odometer reset switch located on the left handlebar control while turning the ignition switch to the ON position. Release the trip odometer reset switch when “DIAG” appears on the odometer display.

What could potentially cause the Body Control Module in a Harley Davidson to fail?

The most common causes of a failed Body Control Module (BCM) in a Harley Davidson motorcycle are electrical issues, water damage, and physical damage to the module. Other factors such as age, wear and tear, and improper installation can also contribute to the failure of the BCM.

Are there any known BCM issues specific to the 2017 Harley Davidson models?

There have been reports of ignition switch issues and low voltage readings on the 2017 Harley Davidson models. These issues can be caused by a malfunctioning BCM. It is recommended to have the BCM checked by a professional if any of these issues arise.

How does a failing BCM affect the overall performance of a Harley Davidson motorcycle?

A failing Body Control Module (BCM) can cause a range of issues with the overall performance of a Harley Davidson motorcycle. These issues can include difficulty starting the bike, failure of the lights and indicators to work properly, and issues with the engine’s performance. It is important to have the BCM checked and replaced if necessary to ensure the smooth operation of the motorcycle.

What steps should be taken to diagnose Body Control Module problems in Harley Davidson bikes?

To diagnose Body Control Module (BCM) problems in Harley Davidson motorcycles, one should first check for any error codes using a diagnostic tool. If error codes are present, they can provide insight into the specific issue with the BCM. It is recommended to have the BCM checked by a professional if any issues arise to ensure proper diagnosis and repair.