The anti-lock braking system or ABS is an advanced safety feature found in almost all vehicles nowadays.
The ABS system consists of the ABS module and the ABS sensors located on each tire. The entire system works in tandem to ensure that your vehicle does not skid or get out of control during heavy braking maneuvers.
The ABS control unit is the main processing module of the entire anti-lock braking system or ABS system of your vehicle. All modern vehicle designs have a pre-installed anti-lock braking system.
The main components of the ABS system are the control module, the valves, and the sensors. The control unit receives essentially all the information, records it, and makes it available to the vehicle’s engine system to ensure that the brakes are applied safely without the vehicle skidding.
Signs of a Bad ABS Control Module
The ABS control module is a life-saving component in a car. But just like any other component, it has a shelf life, after which it can show signs of deterioration.
If the module fails, you will be accident-prone, as aquaplaning and skidding will be much more difficult for your car to control during heavy braking. Fortunately, a failure of the ABS module is easy to detect.
1. Unresponsive Brake Pedal
On some vehicles, the braking is directly connected to the ABS control module. This means that the entire braking function is activated after passing through the ABS module. If this happens and the module fails, your entire braking system will no longer be able to react.
Either you can’t apply the brakes at all, or the brakes don’t react fast enough so that you can brake at a safe distance. This is a life-threatening problem, so it is better to have a mechanic fix it as soon as possible.
2. More Force Required to Brake
If the ABS module fails, it sends incorrect information to the braking system. This causes the brake calipers to act out of character and you need more force to apply the brake.
Not only that, but your vehicle will also take much longer to stop, with the possibility that it will not stop at all. If you feel this effect over time, you should make an appointment with a certified mechanic.
3. ABS Light Illuminates
The ABS has its own warning light which is activated as soon as there is a problem with the brakes. The ABS control module is monitored by the car’s onboard computer so that the ABS light in your dashboard illuminates when a malfunction occurs.
This ABS light can cause a problem with the ABS sensors or the ABS control module, so it is better to go to a mechanic to find out the exact problem. A high-end fault code scanner can usually tell you where the problem is.
4. Locked Brakes
A malfunction of the ABS control module can sometimes cause exactly what the system tries hard to avoid, namely the locking up of the brakes. If you feel that the brakes of your car accidentally lock up or if they are completely locked up and your car cannot drive at all, you may have a problem with the control module.
What is an ABS Control Unit?
The anti-lock braking control unit (ABS) is an electronic module that works like a computer. The information generated by the ABS system’s installed sensors, such as the wheel speed sensors, is received by the ABS control unit. The ECU then uses this data, processes it, and generates the electronic signals to ensure that the vehicle’s ABS system effectively prevents the vehicle from losing traction and remains stable on the road.
It can be considered as the processor and brain of the entire anti-blocking system. Depending on the speed of the vehicle, it also generates commands about how much pressure should be applied to the wheels of the vehicle when the driver depresses the brake pedal.
The control unit is attached directly to the brake lines to make its application effective. The core function of the ABS control unit is to prevent one of the wheels from locking while driving. This is achieved by suddenly applying and releasing the brakes in rapid succession.
The time between each brake application, the frequency of braking, and the number are precisely regulated by the control unit to ensure that the alternating brakes are applied as long as the vehicle is in danger. The data it uses from the sensor includes the way the tires rotate, any event of slippage between the wheels of the vehicle, and any difference detected by the sensor.
Where is the ABS Control Unit Located?
In most modern vehicles, common designs usually require the ABS control unit module to be installed and mounted in the engine compartment. It may also be located in the frame rail on the left side of the vehicle or typically on the driver’s side.
If the control unit module is installed in the frame rail on the driver’s side, the replacement procedure may differ from the case where it is installed in the engine compartment. You may need to lift the vehicle using the hydraulic jack or jack stand to reach the module when you attempt to replace it.
Cleaning the ABS Control Module
The ABS control module may also deteriorate due to the accumulation of dust and deposits. Since it is an electrical and mechanical component, it is necessary to clean it regularly to ensure its proper functioning.
Things you will need
Clean microfiber cloth
Alcohol or cleaner
Process for Cleaning
The process of cleaning requires patience. First, you have to locate the sensor, and we have already told you where you can find it. Once you find the control module, examine it for signs of wear and tear. It is possible that the control module is covered with dust and damaged by deposits.
Continue by using the blower at a low setting. You do not want the dust to contaminate other components. Try to cover the entire area evenly. When you are finished, you will have cleaned all the fresh dust that had settled on the control module. Now it is time to use the cloth to remove all the dirt that has settled on the module.
The remaining dirt can be cleaned with alcohol. Wipe the cloth with a little alcohol and clean the surface of the module, taking care that no liquid comes into contact with any electrical component. Finally, allow the module to dry.
Diagnosis of a bad ABS Control Unit
The diagnosis is important for the ABS control unit, as the same problem can also be caused by other faulty parts. Different parts are connected to the ABS control unit, so the diagnostic procedure also includes tests for other systems, as the symptoms may be caused by a different problem.
The problem may start with a glowing light on the dashboard of your car. However, it is not enough to be sure that the problem is due to the ABS control unit and it may also be due to other parts of the ABS system as well as other systems connected to the ABS system.
To diagnose what exactly the problem is and whether the control unit is bad, the best device that proves effective here is the OBDII scanner. The generated error codes can be a very good way to learn more about the cause of the problem. The OBDII scanner will be able to effectively read the error codes of the OBDII system. You can use a user manual or the service manual provided by the manufacturer to compare and read the error codes with those given in the manual to find out more about the problem.
You can use the error codes to determine whether the problem is related to the ABS control unit. If this is the case, it is usually recommended to have the control unit module replaced. Some vehicles require an ABS control unit that also has a built-in function to control the traction system of your vehicle. It is also usually recommended to refresh the brake fluid after installing a new ABS control unit.
Replacing a failed ABS Control Unit
A poor or failed ABS control unit can also affect a number of other systems in your vehicle, such as the traction control system, the electronic stability control system, and the tire pressure control system, because all these systems are interconnected and networked. It is generally preferable to replace the control unit when there are no physical defects. Here we provide you with easy-to-follow step-by-step instructions on how to replace the control unit of your ABS system.
- Make sure that you keep a service manual or owner’s guide with you provided by your company.
- Acquire all the tools you would need for the replacement along with the parts, i.e. socket sets, protective wears, and screwdrivers.
- Make sure that your vehicle is parked on a leveled surface.
- Keep the emergency brakes on
- Disconnect the battery or remove the cable from the negative terminal
- Locate the ABS control module of your vehicle by referring to the service manual.
- Remove all the connectors and electrical wires from the control unit module.
- Remove the screws and any ties that mounts the module.
- Remove the module from its place
- Match the old module with the new one
- Clean the mounting surface properly.
- Install the new module carefully.
- Hold it in place first with the screws before connecting the wires
- Connect the wires and other electrical connections to the module.
- Reconnect the battery to turn on the connection.
- Start your vehicle and see if the warning light for ABS is gone after a while.
- You may need to clear the error codes in some vehicles.
ABS Control Unit Replacement Cost
The average replacement cost of the ABS control unit is estimated at $900 to $1100. The part itself costs between $850 and $900, while the remaining cost is the labor cost.
The cost of replacing the ABS control unit can be quite high compared to the other parts, as it is the computer of the entire ABS system. The cost of this module can vary depending on the company and the type of vehicle. If you need to replace other parts connected to the control unit, the price will increase accordingly. On average, for most vehicles, just the control unit of your anti-lock braking system will cost you between $850 and up to $900. The cost of this module in luxury cars can be higher. Hiring a mechanic or taking your car to a garage will involve additional labor costs, which in most cases will only be $45 to $200. Therefore, the total cost of replacement, along with labor costs, can range from $895 to $1100.
Hi, I’m Magnus, the owner and the writer of Mechanic Base. I have been working with cars for 10 years, specialized in diagnostics and troubleshooting. I created this blog because I was tired of finding false information on the web while looking for repair information. I hope you enjoy my content!