Summary
The BCM, or body control module, is a crucial component found in most modern vehicles. It supports safety and functions through a network of terminals, wires, and sensors that connect to electronic computer modules.
The module is responsible for several safety and comfort-related functions that are of great value to the driver and other occupants of a vehicle.
While rare, the body control module can experience severe operational issues or even complete failure. That’s why it’s important to know the signs of a bad or failing body control module to tackle the issue before it becomes a bigger problem.
The most common signs of a bad and failing body control module include battery draining repeatedly, erratic electrical function, security system issues, dashboard warning lights, and the car failing to start.
The body control modules are located in a standardized position. They can be found beneath the dashboard.
Let’s dive deep into explaining the symptoms of a bad body control module!
Contents
Battery Draining Repeatedly
One of the signs of a body control module is when your car battery drains repeatedly. This symptoms is sometimes referred to as a parasitic draw. It happens when there is excessive draw from a BCM malfunction, which could quickly drain the battery.
Furthermore, when a BCM provides power to a certain accessory at the wrong time, this excessive draw occurs. Also, MOT tests can cause the issue.
Erratic Electrical Function
An intermittent operation can occur with the various electrical features when a car’s body control module is faulty. These include the wiper, horn, and lights of the car. You can experience failure if these components don’t function properly due to the MOT test performed.
Sudden door lock and radio operation are also warning signs of a bad body control module. You’ll need to book an appointment with a competent mechanic for proper diagnosing of these issue.
Security System Issues
Vehicle’s security system are dependant of body control module. So, if you begin to experience issues relation to security system in your vehicle, you should have it in mind that the body control module is bad or failing. Issues such as keyless-entry or passive-entry function can also be related to the security system issues.
Dasboard Warning Lights
The dashboard warning lights might blow up when the body control module begin to malfunction. You experience this when one or more control modules, such as the transmission control module, powertrain control module, or airbag control module, are unable to communicate with your car’s BCM.
Car Failing to Start
In some situation, your vehicle will refuse to start if the body control module is malfunctioning or faulty. The BCM will fail to recognize the key’s transponder chip, which will simply fail to deliver a “start” signal from the ignition switch.
Also, if the BCM is unable to communicate with other corresponding control modules, you will find it difficult starting the vehicle.
How to Diagnosed a Body Control Module?
The body control module, or BCM, is one of the many onboard computers in your vehicle. The BCM relies on data from an array of sensors and switches all around the vehicle to monitor and control vehicle systems.
Because of this, signs of a faulty BCM can number in the hundreds and can be extremely difficult for technicians to troubleshoot and diagnose.
The body control module, or BCM, controls a wide variety of items in your vehicle, including things such as the power windows, power locks, security system, air conditioning, and even your heated seats.
If a specific system shows an error code or is not properly communicating with the BCM computer (and/or diagnostic tool), the technician may perform any of the following actions:
- Run pin-out testing on the wiring harnesses
- Run one or more function tests on the components using the diagnostic tool.
- Monitor live data on the diagnostic tool to see the component feedback data in real time.
- Check the fuses of associated components.
However, you normally shouldn’t drive with a faulty BCM because of the undeniable nature of lights and electronics. You might find yourself needing your windshield, headlights, or other electronics, but the failed BCM prevents you from operating them.
FAQ
Will A Bad Body Control Module Throw A Code?
The ECM verifies that the transmission is in Park or Neutral. If it is, the ECM then supplies 12 volts to the control circuit of the crank relay. One of the trouble codes triggered by a BCM problem is the U0140 code.
Can A Bad Body Control Module Cause a misfire?
The BCM is responsible for the regulation of a plethora of electronic systems within the vehicle. When the BCM is failing, you may notice erratic behaviors such as the windshield wipers operating independently of input, or issues with the keyless entry system.
Can A Bad Body Control Module Drain Battery?
It can cause a gradual drain on the battery or intermittent issues that may be difficult to diagnose. Addressing BCM issues promptly is, therefore, crucial to maintaining the optimal functioning of your vehicle and preventing further complications.
Read more: What can drain a car battery? Warning signs of a low car battery
Cost Of A Body Control Module Replacement
Replacing a Body Control Module (BCM) in a car can range in cost depending on several factors. The cost can vary depending on the make and model of the vehicle, the location of the repair shop, and whether the part is new or used. In general, the cost of replacing a BCM can range from around £200 to £1000 or more.
That is all for this article, where i discussed the symptoms of bad and faulty body control module. I hope it was helpful, if so, kindly share with others. Thanks for reading, see you around!
