As minor as it may seem, the body control module is the one in charge of the simple functions inside your car such as the lights, the window, door locks, access control, security and other controls that are also related to your comfort. It is called the BCM for short. Though there are also other kinds of control modules operating on your car such as the TCM or the Transmission Control Module, the ECM meaning the Electronic Control Module. Just imagine a library full of different kinds of books. Where do you go in order to find the kinds that you need at the moment? There are systems in the library that can assist you in your search of the book you need for a specific topic. These systems may be in the form of computers or catalogs or numbers in the bookshelves. The control modules in a car works quite similarly like a table of contents in a book or these systems in a library. It is responsible for different functions in the car and no matter how big or small the role it plays, it is still relevant to the whole experience. But what if at some point in your car’s life span, this system starts to let you down? Become faulty and unreliable? We have a quick fix for that. But before jumping into Body Control Module Reset, here are some simple things that will aid you. Let’s get into them, shall we?
Think how convenient it is to have everything in one place. That is how the Body Control Module works. It keeps things organized in the car as the functions related to each other can easily be controlled through the processor or the control module. But as a car owner, you should also remember that the BCM is not responsible for engine-operated functions so if you are having fuel troubles or starting issues, the BCM may not be a prime suspect for any of those because its circle of influence is mainly external.
Unlike the other parts of the vehicle which are strong and durable (such as those found in the vehicle’s engine) the Body Control Module is usually exposed to the elements of heat, moisture and corrosion, also it is vulnerable to humidity. Because of this, the control module is usually subject to damage. Most cars also use cheap materials for them that may also be the stem of its breakage.
What are the symptoms of a bad body control module?
Speaking of organization, you may consider the Body Control Module (BCM) as the head of that department for your vehicle. It integrates the qualities of electronic modules that are interrelated to manufacturing and troubleshooting and connects those qualities to the vehicle. This attribute of the BCM is valuable since you find everything you may need organized in modules or sets, if you may say so, instead of scattered, each having a different control for each function. The BCM is also greatly involved with the security system of your vehicle. Once there is a damage on this control module, the symptoms are easily identified because your car commands being disorganized are also very easy to realize. Here are some symptoms you may experience that would help you determine whether there is a problem with your control module.
- Continuous Stopping of Electronic Components
The Body Control Module has a vast number of functions under its domain or stewardship. Many of which are electronic components consisting of the Lamps both interior and exterior, courtesy and dome lamps, low and high beam headlamps, park lamps, fog lamps, chime warning, door ajar status, wiper controls, the horn, central locking system, the speedometer, the odometer, radio, power door locks, windows. If in any case your BCM is not in good condition, most of these functions put up badly or they may not operate altogether.
- Errors in Security System
One of the most important systems in a vehicle is one that ensures the safety of the driver. A vehicle's security system usually includes the following functions: Remote Keyless Entry (RKE) very good for anti-car theft, Vehicle Anti-Theft Security System also known as the VTSS, Passive Anti-Theft System. These are all associated with the security engagement. If any issues arise with these ones malfunctioning, the probability of the BCM being at fault is high.
- Cluster Warning Light Defects
The Cluster Warning Lights’ main purpose is to indicate or acknowledge an issue with the car. These dashboard lights flash symbols that send out important information about the following (commonly): oil pressure, tire pressure, engine temperature, traction control, anti-lock brake warning, low fuel indicator and the like. You will know that the Body Control Module is having problems once the lights flash on and off.
- Drained Battery
An overly drained battery is usually referred to a parasitic drain. As the name illustrates, this kind of symptom is also important to look into. You call it a parasitic drain when your battery keeps dying when you did not even use it so much and yet it still dies. This fault on the system can take a great toll on the alternator. As it will be susceptible to overheating due to charging a battery that will then get drained quicker than usual.
- Vehicle Won’t Start
You will know that your BCM is not in good condition if you experience a no crank or no start condition. This happens as the Body Control Module communicates with the other module.
What does a body control module do?
In the first parts of this article, we have discussed the functions under the Body control module. But what does it do? Overall, how does this control module affect the vehicle you are driving. To put it simply, the BCM is a body computer to the car. It is the one responsible for monitoring and controlling specific functions such as electronic controls in the car’s body. As mentioned earlier, there are other control modules existing in your vehicle aside from the BCM, and the BCM communicates with these modules that enable the whole system to work synchronously with one another. Normally, the BCM is at the head controls of the power mirrors, power windows, air conditioning, immobilizer, central locking, and still many more functions.
You may be wondering how the body control module does what it does. You may say that the BCM is actually the brain of the vehicle’s casing. Remember how the brain functions with the whole system of the body. The brain receives signals from the different parts of the body and as it receives those signals, it then gives off other signals to meet the needs of the parts. The same goes well with the body control module. As the brain vehicle’s cabin, it has a microprocessor that aids it in controlling various functions. The input devices are the ones that send data to the BCM which in turn triggers the output devices to stimulate reaction to the other functions. As different information travels back and forth from the devices and the BCM, your internal car functions are controlled smoothly. The best part is that the BCM keeps everything together in one casing.
How much does it cost to replace the body control module?
If you are going to the professionals to do the resetting or the replacing of your BCM, you will pay $300 on average. This amount of money is already calculated to cover the parts and the labor. Parts of the BCM will cost you about $150 and the labor will cost you more or less, depending on the hours it takes for the mechanic to fix the control module, about $100. Why the hassle? Because the BCM is the one handling a lot of different functions in the car, it is also inevitable for all those functions to stop working when the BCM does get damaged. When this happens, a replacement may be the best resort for you. Still, the repair cost of the control module also depends on the kind of vehicle that you drive. One factor for the price is also your location as some states also charge fees. And lastly, the cost depends on the mechanic.
You may not be too happy to take out money for this one but if you also consider replacing the BCM, make sure that you purchase a new one. Remember: all Body Control Modules are not manufactured the same or are equally. Make sure that you have the basic information about the kind of software your former BCM uses in order for you to make sure that the BCM you will be using as replacement works accordingly. It is better to purchase a new BCM, not a second-hand even though it works well enough for its past vehicle. The reason this is so is because BCMs are quite sensitive. And if you buy a slightly used one, you may get yourself in the same circle of problems, and may have to replace the control module again.
Can a body control module be reset?
Though the Body Control Module is sensitive, it performs helpful activities in the vehicle you are driving. You now know the symptoms of a faulty BCM, so what? Now you will also have to learn how to repair or reset the control module. The sensitivity of the whole system of the BCM is astounding. With this given fact, be warned that resetting the control module on your own is not just difficult but if the procedure is not performed well enough, you may incur more harm to the vehicle than good. To repair the BCM or any control module for that matter, they have to be reprogrammed which means that a dealer or some specialist must be one to complete the task because they monitor the security codes that enable reprogramming of these systems. Are you confident in your skills to reset the BCM on your own? Read on.
STEP #1 Disconnect Battery
After the troubleshooting, and you finally come to the conclusion that your BCM is the problem, you could continue on the repair process. Safety first! You have to disconnect the battery to prevent yourself from experiencing an electrical shock as you undergo the process. You can do the disconnecting using a wrench or a ratchet.
STEP #2 Locate the BCM
Your vehicle comes with a manual that always comes in handy in any situation of repair. You can go ahead and find a reference from it to know where the control module is. But in many car models, the BCM is located at the back of the glove box compartment or the center console. In order for you to access the BCM and start the repair, you will have to remove these parts. You can do so by unscrewing any screws or bolts.
STEP #4 Remove and Reinstall
Once the parts covering the BCM are removed, you can then start removing the BCM you are to replace. You can use a ratchet to complete this instruction and remove the bolts that are holding the faulty BCM in its place. You may also see a connector clip attached to the BCM, you must remove this as well in order to disconnect the BCM to the whole vehicle. You can now install the new one. Make sure to attach back the connector clip into it and secure it with the bolts you removed a while before. Reinstall the glove box and the center console.
STEP #5 Connect Battery and Test
In order for the BCM to work, you have to connect the car’s battery which is the source of power for the body control module. After connecting, you can then test the problems you have had before have been fixed. Make sure that you follow the specifications in order to reprogram or reset your vehicle’s BCM. Once things are fixed, you know it’s a job well done!
In conclusion, the Body Control Module is a simple part of the system. It is sensitive but also very useful. Fortunately, it also gives off signals when it has problems, pretty obvious ones don’t you think? So, the best thing to do for your car when the BCM sends off those signals, is to pay heed. Get to the problem immediately before things get messy. It may take a bit of your time but it is worth it.