Modern cars are a fest for electronic systems. Compared to mostly mechanical old cars, newer cars are filled to the brim with sensors, controllers, actuators, and control modules. With the complications in technology that accompanied this change, modern cars have modern problems. As with how all things go, you must know that modern problems need modern solutions. Body control module reset is one among them.
- What Is The BCM?
- Where Is It Located?
- Symptoms Of Failure
- Body Control Module Reset Cost
- DIY Fixes
Body control module reset is the process of re-flashing the software in the BCM, short for Body Control Module. This is a central processing unit of the car that governs the functioning of many systems.
It is a part of an elaborate system of ECUs (Electronic Control Units) in the car that includes Engine Control Module (ECM), Brake Control Module (BCM), Suspension Control Module (SCM), and more. A modern car can have more than 80 ECUs, which is a lot of computing power.
Here, let us focus on the Body Control Module. Body control module reset is done when you experience problems with any of the systems that it controls. A malfunction in these systems can be a sign that calls for a body control module reset. Before we delve into that, let us shift our focus to the BCM and the role it plays in an automobile.
Body Control Module
As mentioned above, the BCM plays a vital role in the proper functioning of a car. Like every other ECU in a car, BCM takes input from several devices that include sensors. The information fed into the body control module is then processed to produce a favorable output. This video can help you understand all the ECUs in a car.
The significance of a body control module keeps on rising as modern cars use more and more electrical systems. These can include infotainment systems, driver information displays or dials, the sunroof, keyless entry systems, lights, wipers, and so on. Though these systems may not have a direct link between them, a failure in the body control module can affect all.
The functioning of the BCM is like that of the Engine Control Module (ECM). But unlike the ECM, the body control module controls the systems that are external to the engine. So, if you are experiencing some engine-related issues, BCM may not likely be the culprit.
But if there is some problem with the vehicle’s electrical systems, the BCM is the one to nab. If you are interested in knowing what general 10 problems are the most likely to pop up on cars, you can read it here.
Body Control Module Location
Just like many parts in an automobile, the body control module can be positioned in different locations in different models. But in most cars, you can find the BCM located under the dashboard. It is most likely located on the right side of your steering wheel, under the dashboard panel. In some cars, you may have to take apart some bits of the dashboard to reach it.
Once you reach the BCM, unplugging it is quite easy. There will be several wires plugging into the BCM. You will have to unplug them, an easy procedure, and the BCM can be slid out of its housing.
But why should you go through all this hassle? The system issues in the car that calls for a body control module reset can be a headache, that is why. Allow us to introduce the symptoms that can be signaling the need for a body control module reset.
What Are The Symptoms Of A Bad Body Control Module
The symptoms that show up when a BCM runs faulty are understandably from the systems it controls. Here is a list of all such possible symptoms.
1. Failure In The Operation Of Electrical Systems
The body control module reset is made necessary when the BCM fails to conduct its task properly. Controlling the electrical systems in a car is the primary task of the BCM. So, unsurprisingly the very first symptom of a fault in the BCM operation is a drop in the performance of any of these electrical systems.
If you see some of the systems including horns, lights, warning chimes, locks, dials, stereo, wipers, interior lamps, clock, odometer, etc. failing or operating incorrectly, it can be an issue with the BCM. Your body control module reset may be closing in.
These issues do not have to be a complete failure of an electrical system. Most early symptoms are usually trivial with no significant damage. For instance, if the clock, odometer, saved radio frequencies, etc. are getting reset every time you start your vehicle, your body control module reset may be coming up.
2. Drained Battery
A drained battery can mean a plethora of things. It can be a failure with the alternator, or it can be a light that you forgot to turn off, or it can mean that the battery itself has died. Apart from these obvious issues, a fault with the BCM can also trigger battery drain.
This kind of battery drain is called parasitic drain as the battery has dried out even when not using it. When you turn a car off, there are some systems that leech some charge out of the battery under normal circumstances. These include your clock, security alarm, immobilizer, and radio presets. The battery is made to handle this drain, and these will not drink all the juice from it over a few nights.
But if the body control module reset is impending, this drain can be too much for the battery to handle. This can overload the battery and completely exhaust its reserves. So, the next time you encounter a dead battery, keep this in mind. Your body control module may be in need of a reset.
3. Cluster Warning Lights
If you turn your car on and the instrument cluster lights up like it is Christmas, it can be a BCM issue. If one or two of those lights stay illuminated for a while, it can be an issue with those respective systems. For example, if the ABS light stays on for a while, you may want to check the ABS module. This is not an issue with the BCM.
But if the warning lights on the cluster start flashing on and off, the BCM may be to blame. This flashing can occur when the body control module is unable to read the sensors correctly. This is an obvious sign that a body control module reset is needed.
When this happens, you may also experience a drop in the vehicle performance as the body control module will communicate with other systems in the vehicle.
4. Burnt Fuse Box
As a body control module reset is a process associated with electrical faults, a fuse box can be a place where problems can occur. The fuse box is likely one of the first casualties when an electrical issue crops up. This time too, it is not different.
Smoke coming out of the fuse box or a burnt smell can indicate overheating and failure of the fuse box. If this happens, get your vehicle checked by a professional. You may have repair bills coming your way.
Overheating of the fuse box or a failure in the fuse system can be an issue that calls for a body control module reset. On top of this, you will also need to fix whatever that went wrong with the fuse box.
5. Jerking Under Acceleration
Acceleration of a car will bring in some vibrations into the cabin of the vehicle. But if they go beyond a certain degree, it points at something that has gone wrong in the vehicle. Trouble inside the body control module can be a cause of excessive jerking or shaking.
This becomes more evident when you slam on the throttle. Under heavy acceleration, the jerking can be quite noticeable. If this happens, a body control module reset may be in order. But do not be mistaken.
Severe jerking of the engine can be caused by several other factors as well. So, before you deduce a body control module reset, get the help of a professional. A trained eye can spot any other issue in the vehicle that can cause this jerking.
6. Reduction In Acceleration
Just like the jerking of the engine, a reduction in the acceleration of the vehicle can hint at a body control module reset. But just like the jerking, a BCM issue is not the only problem that can reduce the pickup of a vehicle. So professional help is necessary to trace the issue back to its root cause.
A body control module reset may be all that you need to restore your vehicle’s original acceleration. If your luck is not that good, it can be some mechanical issue.
7. Security System Errors
This is tied to the electrical failures that we talked about, a couple of paras before. The entire security system of vehicles including Remote Keyless Entry and Anti-Theft Systems uses the BCM as a central brain for their job. Any failure in the BCM can reflect a malfunction of these systems.
If the security system of your car fails, the BCM may be to blame. A body control module reset can rectify this issue. Finding a fault with the security system demands your immediate action, as it may prepare the ground for easy theft. An appointment with your trusted garage should be your first order of business if you spot something wrong with these important systems.
Why Do You Need A Body Control Module Reset
As we have established, the body control module is a key part of a vehicle’s electrical framework. In fact, if the BCM fails, almost all the electric arsenal of the vehicle will not work as intended.
Hence, a body control module reset is a necessary repair procedure that can never be ignored. But luckily, the BCM shows off signs of its last legs clearly, enabling you to take quick action. So, if you suspect that your BCM is acting up, perform a body control module reset, and that should be all it takes to alleviate your pain.
If you really want to be certain that you need a body control module reset, you can try plugging in an OBDII scanner into your car’s ECU. And, see if you’re getting any of these BCM-related OBD diagnostics error codes, telling you that there’s something wrong with your car’s body control module:
- U0140 – Lost Communication With Body Control Module
- U0141 – Lost Communication With Body Control Module A
- U0142 – Lost Communication With Body Control Module B
- U0143 – Lost Communication With Body Control Module C
- U0144 – Lost Communication With Body Control Module D
- U0145 – Lost Communication With Body Control Module E
- U0422 – Invalid Data Received from Body Control Module
- U1064 – Lost Communication with Body Control Module
- P1381 – Variable Cam Timing Overadvanced (Bank 1)/Misfire Detected – No Communication with BCM
Body Control Module Cost
The body control module reset is a process that needs professional help. If you are not familiar with replacing parts on a vehicle, the BCM is not a good place to start. This project can be expensive too, as the BCM is an integral part of the car’s electric system.
Combining the part and labor costs, a body control module rest can cost around $300. The price is almost always evenly split between parts and labor, with the module costing $150 and labor following suit. The body control module reset costs, like other maintenance procedures, can vary according to different factors.
The model of the vehicle is a primary influencing factor for this variation in cost. Some vehicles have the BCM positioned deep inside the dashboard. This will need your mechanic to remove more panels than usual, to scuba dive into the confusing matrix of wires.
Fitting them all back together after the task is complete is also going to be an uphill stride. Hence, more hours of labor. More money. The body control module replacement costs also depend on the state you are in, the mechanic you approach, and more.
But all this is worth it, as your vehicle’s peripheral systems are almost all dead without a proper BCM. If you choose to replace the BCM completely, make sure you pick up the right unit. For this, information regarding the version and kind of software the old BCM uses is needed.
This can ensure that all your systems will function normally once you fit the new one in. Also, it is recommended to stay away from buying used BCMs. They are very sensitive units, and these can go wrong soon after you fit them in. Then you end up in the same loop again.
How To Reset Body Control Module
Now, we have a section for the grease monkeys who dare to get their hands dirty doing a body control module reset. Though it is technically possible to perform a body control module reset from your home yet, it is to be noted that the BCM is highly sensitive.
The wrong procedure of resetting the module can end up doing more harm to the vehicle than good. The procedure itself can be cumbersome and intricate.
It is always recommended to employ the dealer to carry out the body control module reset. They are better versed in monitoring the security codes that enable the reset. Also, if something goes wrong with the programming, they are equipped with the tools to counter it.
If all this horror-filled buildup did not scare you away from a body control module reset, worry not. We have the right guide for the adventurous journey that lies ahead of you. Here are the steps to perform a body control module rest by yourself.
Body Control Module Reset, Step 1: Disconnect The Battery Terminals
It is always recommended to disconnect the car battery from the system before you lay your hands on anything electric in the vehicle. Safety is paramount and risking an electric shock is not worth it. So, keep yourself safe before you dive into the process.
Body Control Module Reset, Step 2: Find The BCM’s Location
The BCM in most vehicles is located inside the dashboard. But it differs from model to model. The deeper the location of the BCM is, the harder it will be to reach it. Your vehicle’s repair manual can help to trace the BCM easily.
A simple Google search may also suffice. If even the search engine gods cannot help you, you can contact a seasoned mechanic and seek his/her advice to locate the body control module.
Once the location is traced, it is mostly a matter of unscrewing some bolts and screws to expose the BCM. The number of panels to be removed depends on your make and model. If you want to know how the make of a car affects your ownership experience, you can read about it here.
Body Control Module Reset, Step 3: Removing The BCM
Once you have located the body control module, the next thing to do is to remove it, obviously. A ratchet can help you unbolt the BCM from the housing. You will have to unplug the connector clips attached to the BCM to remove them completely from the housing.
The wires must be unplugged. Keep track of the wires while unplugging. This can make your life easier when you fit in the new BCM.
Body Control Module Reset, Step 4: Reinstalling The BCM
If you are replacing the BCM, you must ensure that the part you buy is the same as what you have removed. If not, the systems in your vehicle may fail to work properly. Once you have the right part, it is just a matter of doing the steps that you did to remove the BCM, but in reverse.
Plug the wires and plugs in, slot the BCM into its housing and bolt it tight.
Body Control Module Reset, Step 5: Reconnect Battery
To complete the body control module reset, you will have to reconnect the battery. This reestablishes the electrical supply through the BCM as well as other electrical peripherals of the vehicle.
Once the battery is reconnected, check if the problems that made you perform the body control reset have been rectified. If yes, pat yourself on the back for a job well done. And that wraps up our attempt to DIY a body control module reset.
Alternatively, you can also try isolating the battery and draining the charge from all ECUs. In some vehicles, this may be able to do the trick. But note that once you do this, everything in the vehicle’s memory will be wiped out, including your saved radio stations.
More critically, the vehicle will have to relearn its optimal working conditions. But keep in mind that this is just a preliminary attempt to alleviate electrical issues that may be triggered by a faulty BCM. If this does not solve your issue, your new BCM must be reprogrammed by a dealer.
They use specialized diagnostic scan tools to perform the reprogramming procedure. This establishes proper links to the sensors and other systems of the individual vehicle.
Body Control Module Reset: In Conclusion…
It is now clear that a body control module reset is an important procedure. The BCM is a delicate part but with a strong function. Given the important role the BCM plays in a car, the money and time put into it are worth it.
So, if your vehicle is showing symptoms that demand a body control module reset, do not hesitate. Give your vehicle the proper treatment it deserves, and you should be taken care of for the next many miles.
FAQs On Body Control Module Reset
If you’re still curious to learn more about a body control module reset, our FAQs here might help…
What Is The BCM
As newer and more modern cars feature a greater number of electronics, there’s a growing need for more complex BCMs. Also known as, the body control module. The primary role of the body control module is to act as a central unit for processing load drivers and coordinates the actuation of various electronic accessories on your car. These include your alarms, power windows, ADAS, windshield wipers, climate control, and more. Essentially, each of those components has its own microcontrollers to activate them when you need to say, turn on the climate control. But, it’s the BCM that integrates all of those functions into a singular unit, capable of effectively coordinating your car’s electronics.
What Happens When A Body Control Module Goes Bad
When your car’s BCM (body control module) fails, it can exhibit numerous noticeable symptoms. Among the easiest and most obvious is the failure of your car’s accessories and all other electrics. For instance, you might notice your lights aren’t turning on, if the horn starts honking randomly, or if the radio isn’t working right. Beyond this, you’ll note other tell-tale signs of a faulty BCM, such as numerous warning lights popping up. Or, a drained battery, as well as burnt fuses and issues with your car’s anti-theft system. A few other side effects will relate to your car’s performance, such as noticing reduced acceleration or jerkiness from the car as you’re driving around.
What Does The BCM Control
Your car’s BCM (body control module) controls a vast array of individual components. Thus, interconnecting all their functions, as well as communication and activation, into a single, efficient, and easy-to-control unit – the BCM. Some of your car’s accessories that are integrated with the BCM include the alarm (also the anti-theft system), advanced driver aids, active safety systems, power windows, lights (interior and exterior), windshield wipers, power locks, power mirrors, and much more. The goal here is to simplify a car’s oft-complicated and archaic network of wiring and microcontrollers into a single module. There are plenty of other benefits afforded by the inclusion of a BCM, too.
How To Reset Car Computer Without Disconnecting Battery
Among the most popular method of resetting a car’s computer (otherwise the ECU or ECM) is by disconnecting the battery. Thus, draining the computer of any residual power, thus resetting it. But, you could also reset a car’s computer without needing to disconnect the battery. You can do this by finding the fuse box, and locating the fuse that’s labeled with the tag, BACK-UP, or EMU/ECU. Now, remove those fuses, and leave them be for 10 to 15 minutes. Once that timer’s run out, re-install the fuses, restart your car, and go for a short test drive. Confirm if any issues that you have beforehand are now fixed and that the check engine light has been turned off.
How To Test A Body Control Module
Generally speaking, BCM-related diagnostics and testing are best left to professional mechanics who know the ins and outs of how to work with a BCM. This is mostly owned to just how complicated the BCM is. But, there’s still some testing that you can do, and that involves checking the connection between the body control module (BCM) and your car’s fuse box. You may begin by disconnecting the negative terminal from the battery and setting your ohmmeter to the OHMs setting. Now, touch one of the leads to one of the terminals on the BCM connector, with the other lead on the respective fuse box terminal. If there’s no reading, then it’ll highlight a faulty connection.
These tools have been tried and tested by our team, they are ideal for fixing your car at home.