When your ABS light or traction control lights illuminate, it’s essential that you
identify its source. While it could be any number of causes for them to illuminate,
oftentimes they’re due to faulty wheel speed sensors or module failure.
Follow this guide to gain more understanding about why these lights are illuminated, and how you can fix them.
1. Faulty Wheel Speed Sensor
If your ABS and traction control lights have come on, replacing one or more wheel
speed sensors may be necessary. A random electrical issue could be the culprit here;
including chafed circuit wiring, sensor or connector corrosion, misaligning pulse
wheel teeth misaligning with sensor teeth gaps being too big and improper sensor
fitment being some causes for failures in these sensors.
The ABS computer uses wheel speed sensors to track vehicle rotation and apply
pressure at specific wheels in order to maximize vehicle stability and handling, while
providing information to the car’s engine management system that optimizes
ignition timing and fuel efficiency. As each wheel spins, its signal increases in
frequency; without using scan tools or oscilloscopes it may be hard to diagnose any
potential sensor problems; in such instances if replacing one it is recommended that
battery is first disconnected as this helps reset it and avoid pulling any unnecessary
error codes during this process.
2. Faulty ABS Control Module
When one of these lights illuminates, it typically indicates either that an ABS sensor
has been tripped or that there has been an issue with wheel speed sensors.
Sometimes however, an ABS light can also come on when applying parking brake.
The ABS system works through sensors at each wheel that communicate wheel
speed to an ABS control module. If wheel speeds change suddenly when braking,
this could signal loss of traction resulting in ABS light activating.
ABS modules tend not to fail often as most have multiple layers of redundancy builtin. When your ABS light comes on, however, this could be an indicator that it may be
time for replacement. Depending on the year, make and model of your vehicle,
replacing an ABS control module can be either simple or complex process; typically
this should be handled by a certified professional; however if you possess some
mechanical aptitude and follow an online video tailored specifically to it can save
yourself both money and time by doing it yourself.
3. Faulty ABS Pump
The ABS pump is responsible for keeping wheels from locking up when you press on
the brake pedal, acting as a critical safety mechanism to help reduce skidding and
prevent accidents. Unfortunately, like all mechanical parts, its wear and tear cannot
be ignored, meaning if your car’s traction control or ABS light comes on as soon as
something seems amiss it should be addressed as soon as possible.
One telltale sign that your ABS module has failed is when your brake pedal feels
spongy. When your ABS modulator detects that you are applying hard braking, it
pumps more brake fluid into your master cylinder than usual and this causes your
speedometer to show slower or faster driving speeds than is actually happening.
An improper ABS module can also cause your brakes to pulse, increasing stopping
distances and decreasing their “feel.” Before replacing it, check for external issues
like low brake fluid levels or blown fuses that may need addressing first.
4. Faulty ABS Sensor
Failure of an ABS sensor (also called an abs brake or wheel speed sensor) is the
source of ABS and Traction Control lights on your car, communicating information
regarding steering and braking to its computer which then analyzes this data to
control various systems on board your vehicle.
No matter the source of the trouble with an ABS sensor – be it its wiring or its
internal mechanism – its outcome remains the same: an improperly functioning ABS
sensor can lead to Stability and Traction Control warning lights appearing on your
dashboard. Do not disregard these messages; driving a car without these systems
disabled can cause serious problems and accidents.
Replacing an ABS sensor should be straightforward if you possess the appropriate
tools and possess some mechanical knowhow. A ratchet and socket wrench will
enable you to quickly unbolt and replace a broken sensor with a new one; once
complete, use your scan tool to check any stored codes within your ABS module to
pinpoint exactly why your warning light flashes.