How To Reset Body Control Module (BCM) To Fix Electrical Issues

If your car’s power windows, lights, or even the locks have been acting strangely, your car’s Body Control Module (BCM) might need a reset. A BCM reset helps restore the communication between your car’s electrical components, preventing headaches and costly or complicated repairs. A ‘reset’ of the BCM is a simple process of re-flashing the software.

Given that the BCM is the central processing unit of your car that governs the functioning of many of its electrical systems, it works closely with other ECUs (Electronic Control Units), including the 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.

If you’re keen to learn more, down below, we won’t just explain how you can easily reset your car’s Body Control Module (BCM) step-by-step, but we’ll also look at diagnosing common issues. In addition, we’ll also discuss whether or not you should do this yourself, or if you need to seek professional help.

What Is The 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.

The significance of a body control module continually rises, as newer cars use more electronics. 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 most of 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.

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, which is an easy procedure, and the BCM can be slid out of its housing.

With that in mind, the BCM’s location varies by vehicle model. While you can commonly find it under the dashboard on the driver’s side, it may also be located behind your glove box, under your car’s center console, or even in the engine bay. It’s wise to consult your car’s owner’s manual or a repair guide for the BCM’s precise location.

Cost Of Resetting The Body Control Module

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.

• A fairly simple Body Control Module (BCM) reset at a dealership typically costs between $80 to $150, depending on labor rates. However, if more in-depth reprogramming of the BCM is required, the costs may rise to $200 to $300.
• Meanwhile, a BCM replacement, including parts and labor, can cost around $300 to $600, depending on your vehicle model. The module itself typically costs around $150 to $400, while labor fees vary based on accessibility and complexity.
• 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 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.

How To Reset Body Control Module?

CAUTION: 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.

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 and body control module reset procedure, 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. Remember, be warned that for most folks, it’s better to visit a dealer and let them do this, instead.

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.

Moreover, since the BCM is a highly sensitive component, here are some extra precautionary measures and safety tips to best ensure your safety when working with the BCM itself:

• Disconnect the battery before touching the BCM to prevent any damage.
• Use a pair of anti-static gloves or ground yourself to avoid static discharge.
• Handle the BCM (Body Control Module) gently, as any physical damage could corrupt its internal circuits.
• Do not attempt BCM reprogramming without proper tools, as incorrect coding may cause further malfunctions.

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, and there ought to be lots of information on forums specific to your car’s make and model.

If Google can’t help you, you can contact a mechanic and seek their 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 and removing interior trim panels to access it. Remember, a repair manual will be indispensable in providing you with all the steps and information you need.

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. 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. Be gentle, as some of these clips and connectors are very fragile, especially on older cars.

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. One easy trick I’ve learned is using my phone to take lots of photos of the cabling and wiring while I’m doing this. When taking those photos, focus on where the wires/cables go and where they plug into, and keep them in your back pocket.

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! Alternatively, if it’s not working right off the bat, 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 (among other data).

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.

Bad BCM Symptoms

Now, if you’re wondering whether or not your Body Control Module (BCM) even needs a reset, it’s worth discussing some of the early signs of failure and symptoms associated with a bad BCM. A faulty BCM can lead to various electrical and operational issues with your car, including:

• Electrical Malfunctions – This encompasses randomly flickering dashboard lights, erratic warning signals, or even your car’s headlights turning on and off unexpectedly.
• Unresponsive Power Windows & Mirrors – Your car’s power windows or powered side mirrors may stop working or operate intermittently.
• Faulty Central Locking System – Your car’s doors may lock or unlock on their own. Alternatively, your key fob may fail to communicate with the car.
• Issues with Interior & Exterior Lighting – The interior lights may stay on or fail to turn on, while your exterior lights could flicker or malfunction.
• Erratic Windshield Wipers – Your car’s wipers may start moving randomly, stop working, or even fail to respond to controls.
• Battery Drain & Starting Problems – A malfunctioning BCM can cause excessive power draw, leading to a dead battery or difficulty starting your car.
• Climate Control Malfunctions – This means that your car’s AC, heater, or defroster may stop working or operate unpredictably.

How To Repair A Body Control Module?

The BCM is like the nerve center of your car, controlling various electronic systems such as the power windows, alarm system, and automatic headlights. As such, when it malfunctions, you may experience various issues with your car. Fortunately, with a few simple tools and a dash of patience, you can repair a bad BCM yourself.

Remember, working with vehicle electronics can be dangerous if not handled properly. If you’re uncertain about any part of this process, consult a professional. Safety should always come first when working on your vehicle.

1. Tools Required for a BCM Repair

To repair a bad BCM, you’ll need a set of specific tools. Gather a wrench, a screwdriver, an OBD2 scanner for diagnosing error codes, and a multimeter for checking electrical connections. Having your vehicle’s specific repair or service manual at hand is also useful for reference.

2. Accessing the BCM

Start by accessing the Body Control Module in your vehicle. Use your wrench and screwdriver to remove the cover and reveal the BCM. Remember to be gentle as the BCM is a critical component of your vehicle’s electronic system. In some cars, they’re also pretty fragile, particularly the connectors and clips that connect to it.

3. Diagnosing the BCM

Now, it’s time to diagnose potential issues with the BCM. Connect your OBD2 scanner to the vehicle’s OBD2 port, turn on the ignition without starting the engine, and run a scan. Jot down any error codes that appear related to the BCM for further inspection.

4. Understanding OBD Error Codes

Error codes can be daunting, but they’re instrumental in pinpointing what’s wrong with your BCM. Consult your vehicle’s manual or look up trustworthy online resources to understand what these codes mean. This step will guide your repair process, as it identifies which aspects of the BCM are malfunctioning.

Here are some examples of BCM-related OBD diagnostics error codes, telling you that there’s something wrong with your car’s body control module:

Error Code	Category	Meaning
U0140	Communication Issue	Lost communication with the Body Control Module (BCM)
U0141	Communication Issue	Lost communication with BCM A
U0142	Communication Issue	Lost communication with BCM B
U0143	Communication Issue	Lost communication with BCM C
U0144	Communication Issue	Lost communication with BCM D
U0145	Communication Issue	Lost communication with BCM E
U0422	Data Error	Invalid data received from BCM
U1064	Communication Issue	Lost communication with BCM
P1381	Engine Timing / BCM Issue	Variable cam timing over-advanced (Bank 1) or misfire detected – No communication with BCM
B1000	BCM Fault	BCM malfunction
B1001	BCM Fault	BCM configuration error
B1676	Power Issue	Battery voltage out of range (BCM-related)
B2477	Programming Failure	BCM programming failure
C2204	Internal Failure	An internal fault within the BCM

5. Checking the BCM Connections

After diagnosing the issue, check the BCM’s electrical connections. Use your multimeter, set it to continuity mode, and verify there’s a continuous connection between the BCM’s input and output. Disruptions in continuity could suggest that your BCM’s wiring is the problem.

6. Repairing the Wiring

If the multimeter test reveals wiring issues, you’ll need to address these next. Carefully inspect the wiring connected to the BCM. If you find any frayed wires, loose connections, or damaged components, they’ll need to be repaired or replaced.

7. Testing the BCM Post-Repair

Once you’ve repaired the wiring, it’s crucial to test the BCM again. Reconnect everything, turn on your vehicle’s ignition, and use the OBD2 scanner to perform another scan. If no error codes pop up, the repair was successful.

8. Resetting the BCM

After all the repairs are done, resetting the BCM can often be beneficial. To do this, disconnect the car battery, wait for about 15 minutes, and then reconnect it. This reset may resolve any minor, lingering issues with the BCM.

9. Verifying the Repair

Finally, confirm that the repair is successful. Start your car and monitor all the electronic functions that the BCM controls. If everything operates as expected, you’ve successfully repaired your BCM. A simple test drive can be really telling, so pay close attention to those systems and electronics that previously failed (are they working right now?).