How to Program a BCM Yourself? Possible or Too Complicated?

When it comes to replacing a BCM, you will need to program it. And unfortunately, it may cost a lot in the dealership. But can you do this on your own? For some vehicles, it's possible and it won't require a lot of equipment and expertise. While for some other cars, programming the BCM is only possible in the dealership.

BCM problems highlights

• Module's importance:High
• Prone to failure:Nounless damaged by water
• Reasons for failure:Water, physical damage, connection problems
• Ways to reset:Only scanner tool
• Sphere of control:Car body, safety, comfort, settings, etc.
• Symptoms of failing:Errors and warnings, functions not working
• Price to repair:$150 - $300
• Price to replace:$550 - $1,100

Why do BCM units need programming?

First of all, let's outline what BCM is. This is the Body Control Module and it controls all the features of your car that don't have anything to do with the engine and transmission. All power-controlled features, smart functions, locking and unlocking, alarm options, etc. are controlled by the BCM.

Of course, in every trim and version of your model, the BCM will have some different settings. For example, a more expensive trim may have folding rearview mirrors and heated seats while a cheaper version may not have these things.

Here's why you need to program a new or used BCM before installing:

• if the unit is not programmed, you will not get access to some features just because they are not set in this module;
• other features may not work correctly like the power windows will not roll down automatically;
• the car may glitch and you will need to reset the units by disconnecting the battery pretty often which is annoying;
• the poorly programmed module may also suffer when getting wrong signals and sending bad commands to the equipment;
• when programming the BCM, you may open the features that weren't there with the old BCM in your vehicle.

Well, it's important to program this module. You may need this whenever you install the used or new BCM in your car. Also, your original BCM may need reprogramming if it was damaged, overheated, or got too high voltage somehow. If the problem with the BCM is ignored or the new unit is not set correctly, you will not be able to drive your car with pleasure.

But how are these modules programmed and what's important to remember when doing it on your own? Let's have a look.

Can you program the BCM on your own?

Well, a lot of older BCM units will not need any programming at all. So, you can just install them and have a happy time driving your car. But this will not work with the newer modules because they have the VIN of their initial car in their settings. So, the security system and the ECU won't communicate with the new BCM unless you program it.

In 90% of cases, programming a BCM is just changing or setting up the VIN and it only takes several minutes for a person who knows how to do it. In some cases, when you want to install the used BCM, it's important to reprogram all functions so that you can use them without any problems.

In short, the process of reprogramming looks like this:

• the new BCM is installed in the car and is checked after that;
• the good professional scanner is plugged into the OBD2 port;
• the special program checks the settings of the BCM and verifies that it's installed correctly;
• then, the program is used to install the needed VIN of your car in the module;
• after that, the mechanic can also change the needed settings or unlock something.

It seems simple and straightforward but you won't be able to do this unless you have a good scanner for your car and also the needed software for this. Actually, every car brand will require a certain program to grant you access to these settings.

So, I can't tell you that it's impossible to program the BCM on your own. But for this, you need to have two things: a proper scanner with the proper software and also experience or knowledge.

Can you just plug in the new BCM and drive?

Actually, your car will be able to drive with the poorly programmed BCM. Some modern vehicles may go to limp mode because the BCM now controls much more functions than before. But overall, the vehicle will work. You may not see the gauges doing their job and your power locks won't work. The security system will go mad, also.

Of course, driving your car like this for a long time is not a good idea. It's unsafe because you basically get a vehicle with no functions and it may lead to a car accident sooner or later. I don't recommend driving with a poorly set BCM - it's not worth it!

New or used BCM for your car?

When the BCM is broken and you want to replace it, you have two choices. You may buy the new OEM part or you may go for a much cheaper module available in the scrapyard or on eBay. The former will cost you a lot of money but will come with a warranty while the latter is cheaper and no warranty is included.

I wouldn't go for a used BCM because of several reasons:

• it's almost impossible to check this part when you are buying it;
• there may be other settings that won't fit your car;
• the module can be burnt or glitchy, you will know this after installing and programming;
• you may spend $100-$200 for labor when installing the BCM and then throw it away.

But for some cars, it's impossible to buy the new body control module, so you basically don't have a choice.

The new module is the best option but it will cost you much more money than you can expect. Also, the dealer will take at least $150 for installation and programming. But at least, you will have the warranty and the part will work well.

Does the dealer really have to program the new BCM?

A lot of car owners go crazy when they learn that their new BCM that just came from the car manufacturer has to be programmed and the dealer takes an additional $100-$150 for this. Why can't the manufacturer make the modules that should be just plugged in?

Well, two things are basically programmed in the new modules:

• the VIN of your car is installed - without this, the module won't do its job and the car will most likely refuse to start and drive;
• the functions are programmed - the BCM is the same for many trims, so the dealer will need to adjust the settings for your version of the vehicle.

That's all, but it still takes some time and effort and the dealer takes money for that. Unfortunately, without this, you will not be able to use your new BCM. So, yes, the dealer has to program the new modules even though they take huge money for that and the job itself may seem unnecessary to you.

Final thoughts

Now you perfectly know why programming the BCM is so important. Also, you can do this on your own if you have the needed equipment and understanding of the process. It doesn't mean it's easy though.

The BCM programming may take some time, especially if you are doing everything using YouTube videos as a tutorial. I won't come up with a guide on how to reprogram BCM because it would take too long to just type the instructions.

Actually, I recommend you find a good independent repair shop that will agree to do the job much cheaper than the dealership. Electronic modules in your car should be programmed by professionals.