The ABS controller is used to monitor the wheel rotation speed and can go out
as electronics sometimes do. This computer module is located on top of the pump
motor and is attached by four or five mounting bolts. If the ABS system stays on
after the key is turned off which is indicated by a humming noise or you have
scanned the system and one of the valve control coils has burned out the unit
needs to be replaced.
In some cases the relay is inside the controller. You can opening the unit up
and replace the relay though it takes some soldering on the circuit board and
finding a replacement relay. Or simply get a replacement from
Amazon for about $270 to $370 depending on the model of your car.
The dealer or repair garage will charge about $650 to $850 for the same job
(parts and labor). If the vehicle is equipped with a traction control system it
uses a different ABS computer then non-traction controlled models which are not
interchangeable. On some cars the controller will need to be reprogrammed in which
case there will be in the instructions with the replacement unit.
Before we begin, you will need to locate the module which is usually under
the hood in the engine compartment or on the frame rail on the driver’s side. Control modules may vary
in appearances but follow the same steps.Watch the video below to get an idea
of what you are in for. Then continue with the guide to gain additional tips and
Before You Begin
Start once you have determined you are going to fix the problem, park the car
on level ground with the transmission in park and the emergency brake set and
the engine turned off.
You may need to jack the car up to replace a control module
and we prefer you learn how to do it correctly while using jack stands.
to use a floor jack and stands
The tools, equipment and supplies seen in the article along with additional
information using specific repair manuals are available at the end of this
Step 1: Remove ABS Computer
Start by disconnecting the battery from the negative cable. Release the
electrical connectors from the unit by pushing the safety clips using a small
screwdriver. One connector will be for the main power and ground for the unit,
(large wires) while the opposite connector will be sensor inputs
and data bus wiring to the main PCM computer which controls when the warning
light comes on.
The weather packing or seal can make it a little difficult to remove the
connectors. Wiggle them gently as you pull to remove them from the module.
There will probably be four or more Torx head (size 20), 8mm or 10mm bolts to
remove the controller from the pump motor. These bolts can be little tough to
get to if the module is under the vehicle like this one. In this case use a 1/4 inch drive
ratchet because its smaller and easier to maneuver. This operation is much
easier when the controller is under the hood.
Make sure the controller is clean and dry. Gently remove the module by
lifting it straight up from the valve assembly. It might be a little stuck
because of the weather seal used to keep moisture out. Use a small screwdriver
to gently pry and loosen the seal to separate it.
Step 2: Match the New Module
After the failed unit has been removed, match the old part to the new
replacement unit. They should be an identical match. Be sure to count the number
of electrical pins in each connector because there are minor variations
according to what options your car has such as traction control.
Step 3: Reinstall the New Module
Next, be sure the pump motor is clean and free from dirt before installing
the new module. Install the new unit and ensure it sits flush and seals
completely onto the valve assembly. This can take some extra effort because the
valve cores need to fit through the module.
After the unit is securely in place, reinstall the mounting bolts and tighten
in an "X" pattern to mount the unit squarely into the pump and valve. This will
ensure the proper operation of the coils over the valve cores.
Once all the mounting bolts are tight make sure the connectors are clean from
dirt and grime. Reconnect the electrical connectors back onto the valve
Reconnect the negative battery cable and start the car. The warning light
should go off shortly after the engine is running or after you have driven the car
for a short time.
Be observant when first driving the vehicle after repairing the ABS system.
Listen for abnormal noises or performance issues that could indicate a problem
which will need further inspection. No code clearing is required in most cases
for American built vehicles. Some older European and Japanese models may need to
be cleared using an ABS code reader. If the warning light remains on after code
clearing it means you still have a problem. If you have any questions about
ABS brakes visit our forum.
There are various tools and supplies you will need to perform these jobs. We
have created a list for you which are easily obtained if you do not have them
Tools and supplies needed for ABS module repair
You will also need replacement parts such as the wheel speed sensor, computer
module or system fuses. We have created a guide that will inform you as to where to go
to get the best deal and quality.
Learn more: ABS
Computer replacement part
To see more specific information about your particular vehicle check out our
repair manual information guide.
ABS Computer repair manuals
Anyone can do car repair if he or she puts their mind to it. If you are a
parent please show your kids how to do car repair because they will need to know this valuable
information as well. Doing the job for yourself, family and friends will give you a satisfaction and pride which you
can only get from doing the job right.
2CarPros will be there for you every step of the way with our repair guides,
and if you have any questions our team of mechanics will answer them for free.