Safety is arguably the most important consumer attribute in new car sales these days. One of the most important technological advancements made over the past 20 years has been the introduction of Anti-lock braking systems, or ABS for short. The ABS system on most domestic and import cars, trucks, and SUVs is controlled by an electronic brake control module (EBCM) that monitors multiple sensors on mechanical systems and relays data to the brake system for smooth and safe braking. However, just like any other electronic device, over time the EBCM could wear out or break. When this occurs, you'll have to replace the electronic brake control module.
The EBCM is typically installed in the engine compartment on most vehicles made after 1995. It's attached to a series of electrical harnesses that are attached to sensors that send data to the EBCM. When the EBCM receives this data, it's able to relay information to and from the vehicle's primary Electronic Control Module. By doing so, it's able to control multiple mechanical parts to ensure proper braking. Some of the elements it controls include:
- The pressure applied from the brake calipers to the rotor
- The length of time the brake calipers apply this pressure
- Down-shifting the transmission to help deceleration
- Reducing brake pressure when tire lock-up or skidding is detected
The EBCM also works with other safety devices including traction control and vehicle stability systems. If this part stops working, it can negatively impact the operation of the vehicle as the braking systems are affected. Sensors are feeding information to the electronic braking control module at all time so it can make adjustments in real-time. A failure of any component inside the EBCM may render it completely broken or useless. When it fails, it will need to be replaced, as there is typically no repair possible unless it's made at an EBCM manufacturer facility.
When this component begins to wear out or fails, it will display a few common indicators or warning signs. Noted below are some signs you can watch for that may signal that your EBCM has stopped working prematurely and will need to be replaced:
The ABS light illuminates on the dashboard. Typically the first indicator that the EBCM is damaged, is that the ABS system light will illuminate on the dashboard. The ABS light is triggered when an error code is activated and stored in the vehicle's ECM. If you see this light on the dash, a diagnostic scan will need to be completed by a mechanic to pinpoint the source of the error code. Once the part has been replaced, these error codes must be reset in order for the repair to become active.
The brakes lock up when depressed. When the EBCM is compromised, the ability of the ABS system to work is reduced. One of the physical symptoms is that the tires may lock up during emergency braking. If this occurs, it's a good indicator that an electrical sensor or the EBCM is damaged and needs to be replaced as soon as possible.
The brakes pulsate when applied. In some rare instances, the brakes will actually pulsate when the EBCM is damaged. This usually occurs at higher speeds when the brakes are gently applied.
The EBCM is also accountable for making sure traction control and anti-lock brakes are working properly. Once this part fails, you’ll no longer be able to count on these braking systems to work properly. If you’re experiencing any of the above mentioned symptoms and suspect your electronic brake control module is in need of replacement, the component must be replaced. For purposes of this article, we'll focus on the best recommended methods for replacing the EBCM on most domestic and import vehicles. The task is very simple to complete once you know where it is located and have the proper tools to remove and replace. However, it's a good idea to purchase and review your service manual for exact steps if they are different for your vehicle.
Part 1 of 3: Determining the symptoms of a damaged electronic brake control module
Unlike replacing the brake pads or rotors, there are no determined service intervals for inspecting or servicing the electronic brake control module. In fact, most automotive manufacturers expect this component to last the lifespan of the vehicle. In most cases, they would be correct to assume this however it is subject to wear and tear and can be damaged due to multiple factors including:
- Exposure to high heat under the hood
- Wires or electrical harnesses being damaged or burned
- Vehicle accidents
Due to the fact that there are no service checks or inspections, part failure is typically determined when symptoms are apparent. Since the EBCM is designed to monitor and in many ways, control the operation of the ABS system, some of these warning signs can be dangerous. It's due to these facts that as soon as these warning signs are noticed, an inspection and proper diagnosis of the damaged component should be completed as soon as possible. Some of the common symptoms of a damaged EBCM include:
Brakes that lock up while stopping in emergency situations
The check engine light or ABS light is illuminated
The brake pulsate during normal braking
Steering wheel vibrates during braking
Warning: Anytime you are working with electrical components, you must remove the battery cables from the terminals. Always remove the positive and negative terminals before you remove any components on the vehicle. It's is always recommended to fully review the manufacturers service manual before attempting to complete this job. As we've indicated above, the instructions below are general steps for replacing the electronic brake control module. If you do not feel comfortable completing this job, always defer to an ASE certified mechanic.
Part 2 of 3: Preparing the vehicle for replacing the electronic brake control module
Replacement parts for the EBCM typically include the module itself. On some vehicles, the EBCM connects to a pressure plate (BPMV in the image above) which has several male electrical fittings that connect into the EBCM. To complete this job, you won't have to raise the vehicle on a hydraulic lift or on jack stands. The EBCM is usually located on the side of the engine. In most cases, the only part you'll have to remove to gain access to it is the engine cover or the air filter housing. In general, the materials you'll need to remove and replace the EBCM; after removing ancillary components will include the following:
- Clean shop rags
- Replacement EBCM
- Torx Screw Set
- Screwdriver(s) flat and Phillips head
- Socket set and ratchet
After collecting all these materials and reviewing the instructions set forth in your service manual, you should be ready to complete this job.
Part 3 of 3: Steps for replacing the electronic brake control module
As with any service, replacing the electronic brake control module will begin with making sure you have clear access to all the tools and supplies you need to complete this task. You don't have to jack the vehicle up or raise the vehicle on a hydraulic lift to complete this job. Please refer to your service manual for detailed instructions as the steps listed below are GENERAL STEPS.
Step 1: Remove battery cables. Remove the positive and negative battery cable and place them away from the battery terminals before proceeding.
Step 2: Remove engine cover and air filter housing. In many instances you'll have to remove the engine cover and air filter housing in order to have free access to remove the electronic brake control module. Refer to your service manual for exact instructions on how to remove these components.
Step 3: Verify that the replacement EBCM is identical to old unit. It is very common for part manufacturers to send the wrong replacement EBCM; especially when ordering online. Before you remove the old component, verify that your replacement part is identical. The most important items to consider are the connectors on the bottom of the plate.
Step 4: Remove first two electrical harnesses. There should be two electrical harnesses on the left side of the EBCM. Using a flat blade screwdriver, pry the clips from the harnesses carefully and remove with your hands.
Step 5: Remove torx screws from EBCM. This unit is typically attached to a bottom plate with torx screws. If this is the case with yours, use a torx screw attachment with a ratchet to remove the four screws from the EBCM. Take them out one at a time and place the screws to the side for now.
Step 6: Remove the old EBCM module. After the screws have been removed, the module should easily pull up. Remove it from the base plate and place aside. On some vehicle, there will be a third electrical harness attached to the back of this unit. If this is the case with your vehicle, remove this harness the same way you removed the first two in step 4 noted above.
Step 7: Install new EBCM unit. The steps for installing the new EBCM are in reverse of the removal. Follow the following guidelines when installing the new unit on your vehicle:
Secure the rear electrical harness to the EBCM
Place the new EBCM onto the mounting plate. It should snap into place with the male electrical fittings on the bottom of the mounting plate
Install the screws but do not fully tighten
Install the two front electrical connectors
Step 8: Follow start pattern for tightening screws. The proper procedure for tightening the torx screws on the EBCM is to do so in a star pattern. Follow the diagram above to ensure the new EBCM is fully tightened before completing this step and proceeding to the next steps.
Step 9: Replace engine cover and air filter housing.
Step 10: Reconnect battery cables.
Step 11: Connect digital scanner and delete stored OBD-II error codes. In many cases when the OBD-II error codes have triggered the check engine light or the ABS light due to a malfunction of the EBCM, they'll need to be downloaded again and cleared in order for the repair to be finalized. If you do not have a digital scanner, contact a local mechanic to complete this step for you.
When you have finished each of the steps above, the replacement of the EBCM has been completed. If you've reviewed the steps in this article and are not confident completing this project or need an extra set of professional hands to help fix the problem, contact YourMechanic.com today and one of our local ASE certified mechanics will be happy to assist you replace the electronic brake control module.
This article originally appeared on YourMechanic.com as How to Replace an Electronic Brake Control Module (EBCM) and was authored by Tim Charlet.