Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Anti-Lock Relay

Anti-Lock relay

The ABS system is a mandatory safety feature found on all late model vehicles. It serves to help slow down the vehicle and prevent wheel lock and tire skid during heavy braking situations. As is the case with the systems on most modern vehicles, the ABS system is electronic in nature, and uses an electronic relay to supply it with power. It is the job of the ABS relay to supply power to the ABS module, pump, and the rest of its components so that they can successfully serve their purpose.

Because the ABS relay is what supplies power to the entire system, when it malfunctions or has a problem, that problem can quickly transfer to the rest of the system, so it should be serviced as soon as possible. Usually, when the ABS relay fails, the vehicle will produce a few symptoms that can alert the driver that there may be a potential problem.

Check Engine Light / ABS Light is on

One of the first symptoms of a defective ABS relay is an illuminated Check Engine or ABS Light. If the computer detects that the relay has failed, or is giving an abnormal reading, then it will activate the Check Engine or ABS Light to alert the driver of a potential problem. The Check Engine and ABS Lights can come on for a variety of reasons, so having the computer scanned for trouble codes can help shed some light on what the exact problem may be.

Unexpected wheel lock from ABS system failing

Another symptom of a problem with the ABS sensor is a non-functioning ABS system. If the ABS sensor fails or malfunctions, then the entire ABS system will be without power and will be unable to function, sometimes without activating the ABS or Check Engine Light. The vehicle may still brake normally, however, the assisted braking provided by the ABS system will be disabled, which may leave the vehicle more susceptible to wheel lock and tire skidding during heavy braking and slippery conditions.

The ABS system is an important safety feature found on virtually all modern vehicles, and as is the case with most automotive systems, it is fed power through a relay. For this reason, if you suspect that your ABS system may be malfunctioning, or needs to have the anti-lock relay replaced, a professional technician, such as one from YourMechanic, can diagnose the vehicle and verify what repairs are required.

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

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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.


Post a question and get free advice from our certified mechanics.


More related articles

How Long Does a Vacuum Brake Booster Check Valve Last?
The braking system on your car requires a lot of pressure. The vacuum booster is one of the main sources of this pressure. This booster will take the pressure that...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...

Related questions

Q: Car won't start - Jeep Liberty

Hi there. From the description you have provided, I assume you have bypassed the ignition switch to determine that the battery and starter are good. If so, and if you are turning the key and only hearing a click, I...

Q: What does the ABS light on the dash mean?

The anti-lock brake (ABS) indicator light on your dash should come on during the system’s self-check when you start the engine, but should go out shortly afterward. If the light comes on again later or stays on, it’s a sign...

Q: Starter issues

Hello. Thanks for writing in about your 2000 Plymouth Voyager. The starter should have two wires going to it. The brown one will operate the starter solenoid on the starter to allow the large red wire at the starter to...