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What is an ABS control module?

The anti-lock braking (ABS) control module is a computer that

constantly receives information from the wheel speed sensors, and uses that data to prevent the vehicle from losing stability and traction in case the need arises.

How does the ABS control module work?

The ABS system is designed to keep the brakes from locking up on one of the wheels while the vehicle is in motion by quickly engaging and disengaging the brakes in rapid succession until the vehicle is out of harm's way. The ABS control module is the brain of this system, and is physically attached to the brake lines to control the amount of pressure that is being applied when the driver depresses the brake pedal.

What are the symptoms related to a bad ABS control module?

Generally, if the ABS control module fails, the brakes will still function, however, the vehicle will not have skid protection in a turn, under hard acceleration, during hard braking, or if any of the wheels leave the tarmac. ABS, traction control system (TCS), and vehicle stability warning lights will illuminate on the dashboard if the ABS control module suffers failure, and trouble codes specific to the ABS system will be stored in the ECU memory.

Can I drive with an ABS control module problem?

Failure of the ABS control module does not disable the vehicle, but safety is a concern as drivers become accustomed to the road manners of their vehicle's. If hard braking that is normally controlled by the ABS control module is necessary, a collision may occur. We do recommend towing the vehicle to a repair facility if the brakes feel unusual under light or normal driving conditions.

How often do ABS control modules need to be replaced?

ABS control module replacement is less common than most other repairs. If the brake system is properly maintained, the ABS control module can be expected to last the lifetime of the vehicle in most cases.

Anti-lock braking systems are complex, and are typically diagnosed through professional computer scanning equipment, or manufacturer specific software. The technician will communicate with the ABS control module via computer, and view real-time data to determine what fault has been detected, and how the system is behaving. Finally, if the module is suspected of failure, the module inputs and outputs must be tested physically to ensure the ABS control module is at fault before confirming the diagnosis.

How is a ABS control module replaced?

Once the battery is disconnected, the technician must remove all electrical connections from the module, and all brake lines from the distribution block, which is attached to the ABS control module. Once the new control module is installed, the brake system is flushed and bled, and manufacturer specific software updates will be made.

ALRAFAY Recommendations for ABS control module issues

During this repair, the entire braking system should be inspected, and the brake fluid will be completely flushed and replaced to prevent contamination of the new ABS control module.

What to look out for when dealing with ABS control module issues

The ABS module should not be assumed faulty, and must be tested to prevent costly misdiagnosis. They are typically very expensive, and, normally, the part is only available for purchase from the manufacturer. Replacement cost will vary for different makes and models because of parts pricing differences, and accessibility issues for the servicing technician.

Can I replace the ABS control module myself?

Replacing the ABS control module requires advanced knowledge, and manufacturer software in order to update the new control module. This is not a DIY friendly repair.

Your Toyota Prius’s ABS Light comes on when it fails a self diagnostic cycle. When on, it indicates that the Prius does not have Anti-Lock brakes, and the safety they provide.

Your Prius’s ABS system uses a system of sensors to determine wheel speed when braking. If one of the wheels is starting to lock up, it’ll apply the maximum amount of brake to that wheel in order to keep it from sliding.

Wheels that are turning will slow a vehicle faster than a locked wheel. Skidding tires also create flat spots in the tire, which can be inconvenient and dangerous in itself. ABS also allows you to be able to steer the vehicle while slowing down, and has been around for so long that many drivers have never driven a vehicle without it.

Is it Safe to Drive Your Prius?

The ABS light is different than the brake warning light itself. The brake light indicates that there is a problem with the physical braking system and that your Prius is unsafe to drive.

Yes, you can drive your Prius with the ABS light on. Is it safe? It’s not as safe, especially when it’s raining, snowing, or the road surface is loose/uneven. That’s why we recommend having the ABS system fixed as soon as possible.

Toyota Prius ABS Light On Causes

A good code scanner will often tell you which part of the ABS system has gone bad. Not every OBDII scanner will give up this information. A good one will. Most auto parts stores will have a free scanning service that they would be happy to let you utilize.

Here are the three most common causes of the ABS light coming on:

1. Wheel Speed Sensor

The wheel speed sensors are responsible for monitoring the wheel speed and sending it back to the computer system. If one of the wheels is moving slower than the others it on its way to locking up. The ABS then takes activates on that wheel in order to keep it from locking.

When this sensor is no longer sending a signal to your Prius’s ABS system, it is no longer functioning properly and the ABS light will be activated on the dashboard.

2. ABS Module

The antilock brake system runs through the ABS module. This module physically controls the anti-lock brake system If it becomes damaged, and can no longer control all four brakes, the ABS light will activate. Typically, corrosion is the most common reason why the module fails.

3. ABS Fluid Level

If the fluid level is too low to keep pressure in the ABS lines, the ABS light will come on. Without the pressure the ABS will no longer be able to physically activate.


It is not advisable to ignore your Toyota Prius’s ABS light. Call at 02135383616 Alrafay Auto

get it scan check and Replace

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