Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. Why ABS Control Module Replacements Can Be Tricky

Why ABS Control Module Replacements Can Be Tricky

Why ABS Control Module Replacements Can Be Tricky

All vehicles today have ABS control modules that are integrated with the computer system. In the early 90s, the ABS systems were just becoming more sophisticated and aiding in how the vehicle stops.

ABS, also known as Anti Lock Brake System, is an automobile safety system that allows the tires on a motor vehicle to maintain contact with the road surface at all times according to operator inputs while braking, preventing the wheels from locking up and avoiding an uncontrolled skid.

Today ABS is not just to keep the wheels from locking up but it aids in traction control as well. The operator has the feature to turn on and off traction control. When the traction control function is operational, as the vehicle's wheels tend to spin faster than the other on a straight surface, meaning not during a turn, then the anti lock brake system will apply braking force to the wheel that is not in full contact with the flat surface.

Anti-lock brake systems can be very tricky when replacing a control module, since it is the brain for the system.

Most ABS systems today have hydraulic circuits running to all wheels on every actuator. Older ABS systems only had circuits running to only two wheels on every actuator. By having all of the circuits running to all of the wheels makes the system more effective and if an actuator was to fail during an ABS event, then all of the wheels will still have full braking force.

When removing an anti-lock brake system controller, there are many brake hydraulic lines connecting to it; Usually there are between eleven to fifteen lines connected to the ABS controller. There must be a drip pan under the ABS brake controller to prevent any brake fluid from coming in contact with any painted surface.

  • Note: When dot 3, dot 4, or dot 5 brake fluid comes in contact with paint, the brake fluid will chemically destroy the paint all the way to the applied surface (like a fender).

As the lines are removed, be sure not to bend or twist any of the lines, for this will cause a nightmare to change out any broken lines. Some of the brake lines are short and only go to a leveling valve or a combination valve, however, some lines travel the full length of the vehicle.

Before removing the cannon plug on the ABS controller, be sure to disconnect the battery for any discharge of electrical contact. This will prevent any shortages between the ABS controller and the vehicle's computer.

When installing a new ABS controller, the cannon plug should be the first item to connect. Then install all of the brake lines making sure that all of them are threaded incorrectly and not cross threaded.

  • Warning: If any brake lines are cross threaded, the ABS module will display a code for loss of pressure and brake fluid will leak out at a great force into the engine compartment and may not apply any pressure to the brake system.

As all of the brake lines are installed, a bleeding process needs to be followed. It is very important to follow the ABS controller bleeding process and proper sequence to ensure that there is no air in any brake line. This can be very tricky and will cause irritation to the mind.

  • Note: If there is no way to knowing the bleeding sequence, the rule of thumb is to start bleeding the brakes from the farthest connection point all the way up to the closest connection point to the master cylinder, then bleed the master cylinder last.

If you need to replace your ABS control module, book one of our automotive specialists at YourMechanic and we'd be happy to help.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...


Related questions

Q: Car accelerated upon applying the brake, tires squealing 2015 Acura TLX

Hello, as I'm sure you are aware this is incredibly dangerous! "Unsafe to drive", are the words you may want to use when you bring it to the Acura dealer service department to have them check it since the vehicle...

Q: My 05 nissan altima wont start

Hi. This problem does sound like a faulty fuel pump could be the problem. If the fuel pump is weak or completely faulty it will cause the problems you have described. There may also be a problem with the car...

Q: ABS light on

There are many parts involved in ABS. The most common reason for this is a faulty wheel speed sensor. There is one sensor for each wheel. They are mounted near the wheel bearings and get exposed to all the elements....