Why Is My ABS Light On In My Jeep Wrangler? Causes, Diagnosis, And Fixes

If the ABS light is on in your Jeep Wrangler, the vehicle has usually detected a problem that may prevent the Anti-lock Braking System from working correctly. A failed wheel speed sensor is a common possibility, but damaged sensor wiring, a bad wheel hub or bearing, electrical faults, ABS module problems, tire changes, and several other issues can trigger the warning.

Do not assume the light automatically means you need an expensive ABS module. Start with a proper diagnosis.

Jeep states that the ABS warning light normally comes on briefly when the ignition is switched on. On a Wrangler JK, for example, it may remain illuminated for up to about four seconds during the system check. If it stays on or comes on while you are driving, the anti-lock portion of the braking system needs attention. Conventional braking may still operate if the red Brake Warning Light is not also illuminated.

This guide explains what can cause a Jeep Wrangler ABS light, how to narrow down the problem, whether you can keep driving, and what you should check before buying replacement parts.

What Does The ABS Light Mean On A Jeep Wrangler?

ABS stands for Anti-lock Braking System. Its job is to help prevent the wheels from locking during hard braking so you have a better chance of maintaining steering control.

Your Wrangler performs an ABS self-check when it starts and begins moving. Clicking, motor noise, or a brief ABS warning light during this process can be normal. Jeep also notes that brake-pedal pulsation and certain mechanical sounds can occur when ABS is actively working.

What is not normal is an ABS light that stays illuminated after startup or suddenly appears while you are driving.

That means the system has detected a fault and may disable some or all anti-lock functionality until the problem is repaired.

Is It Normal For The ABS Light To Come On At Startup?

Yes. A brief ABS light during startup is part of the normal system check.

You should be concerned when the light does not go out, comes back after you begin driving, or appears together with other warning lights.

What Happens When The ABS System Is Disabled?

Your regular hydraulic brakes may still work when only the yellow ABS warning light is illuminated. However, you may lose the additional wheel-lock protection provided by ABS during hard or slippery-road braking.

That distinction matters. An ABS warning should not be ignored simply because the brake pedal still feels normal. Jeep recommends having an ABS fault serviced as soon as possible.

12 Common Reasons Your Jeep Wrangler ABS Light Is On

There is no single cause that applies to every Wrangler. The problem can vary considerably between a TJ, JK, JL, JLU, or Wrangler 4xe.

These are the areas worth checking first.

1. Faulty Wheel Speed Sensor

A bad wheel speed sensor is one of the first things worth investigating.

ABS-equipped Wranglers use wheel speed sensors to monitor wheel rotation. Information from those sensors helps the ABS control system determine whether a wheel is slowing or locking unexpectedly. AutoGuru also identifies wheel speed sensors as important inputs to the Wrangler ABS system and notes that a failing sensor may illuminate both ABS and traction-control warnings.

If one sensor stops producing a reliable signal, the ABS controller may store a fault and turn on the warning light.

Do not automatically replace a sensor just because a diagnostic code names one wheel. The sensor itself may be good while its wiring, connector, hub, or signal source is damaged.

2. Dirty Or Damaged ABS Sensor

Jeep Wranglers often spend time in conditions that ordinary road cars rarely see. Mud, sand, gravel, water, snow, and trail debris can collect around the wheel and suspension areas.

Physical contamination or damage around a sensor can interfere with diagnosis. A close visual inspection is especially worthwhile if the warning appeared soon after trail driving, suspension work, or wheel removal.

Haynes recommends inspecting the wheel-speed sensors and their wiring when diagnosing a Wrangler ABS warning.

3. Damaged Wheel Speed Sensor Wiring Or Connector

Sometimes the sensor is not the problem at all.

A wire may be stretched, rubbed through, pinched, broken, or poorly connected. Corrosion or moisture inside a connector can also cause an intermittent signal.

This is particularly important on a modified Wrangler. Suspension movement, aftermarket components, or incorrect wire routing can put additional stress on a harness.

If your ABS light comes on after hitting bumps, making turns, or driving off-road, inspect the wiring carefully before ordering parts.

4. Bad Wheel Hub Or Wheel Bearing

A wheel hub or bearing problem can sometimes affect the wheel-speed information reaching the ABS system.

Depending on the Wrangler generation and component design, the wheel-speed sensing arrangement may be associated closely with the hub and surrounding components. Excessive movement, physical damage, or a problem with the sensor’s signal source can therefore produce an ABS fault.

If your Wrangler has an ABS warning along with wheel play, humming, grinding, or other hub-related symptoms, the entire wheel-end assembly deserves inspection rather than focusing only on the sensor.

5. Damaged Tone Ring Or Wheel Encoder

The sensor needs a reliable rotating reference from the wheel assembly to calculate speed.

If that reference is damaged, contaminated, corroded, or otherwise unable to produce a clean signal, the control module may interpret the readings from one wheel as incorrect.

This is one reason replacing a wheel-speed sensor without testing the complete circuit does not always solve the problem.

6. Low Brake Fluid Or Another Brake System Problem

Check the brake system whenever ABS and brake-related warnings appear together.

The red Brake Warning Light deserves particular attention. In Wrangler documentation, Jeep explains that the brake warning can indicate low brake fluid or a hydraulic brake-system problem. On the JK, Jeep also states that an Electronic Brake Force Distribution fault can illuminate the red Brake Warning Light together with the ABS light, in which case immediate ABS-system repair is required.

Do not simply top up repeatedly low brake fluid without finding out why the level dropped.

7. Blown ABS Fuse Or Electrical Fault

ABS relies on electrical power, control electronics, pumps, valves, sensors, and wiring.

A blown fuse, poor ground, loose connection, damaged harness, or power-supply problem can therefore produce a warning.

Fuse locations and ratings are not identical across every Wrangler year, so use the owner’s information for your exact vehicle rather than copying a fuse number from a different generation. For example, the 2018 Wrangler JK guide lists separate protection for ABS pump, valve/stability-control, and related circuits.

If a replacement fuse immediately blows again, do not keep installing new fuses. The circuit needs diagnosis.

8. Weak Battery, Loose Battery Terminal, Or Low Voltage

Modern vehicle control modules depend on stable electrical voltage. Battery, charging, terminal, or connection problems can sometimes cause multiple warning messages or communication faults.

If your ABS warning appeared at the same time as several unrelated electrical warnings, checking battery condition, terminal tightness, grounds, and charging voltage is sensible.

However, replacing a battery should not be used as a guess. Test the electrical system first.

9. ABS Control Module Failure

The ABS control module receives sensor information and controls the system’s response.

A module fault can trigger the ABS warning, but module replacement should normally come later in the diagnostic process. Sensor faults, damaged wiring, poor connections, voltage problems, and wheel-end faults are often easier and less expensive to investigate first.

A professional scan tool that can communicate directly with the ABS controller is particularly useful here.

10. ABS Pump Or Hydraulic Control Unit Problem

The ABS hydraulic unit uses valves and pump operation to control brake pressure during anti-lock events.

A pump, valve, electrical, or control-unit problem can produce an ABS warning. Jeep’s Wrangler JK documentation specifically identifies ABS pump and valve circuits in the electrical system, confirming that these are separate parts of the ABS control arrangement.

Hydraulic ABS faults are not good candidates for guesswork. Accurate fault-code diagnosis is important before expensive components are replaced.

11. Steering Angle Sensor Or Wheel Alignment Problem

ABS does not operate completely by itself. It works alongside other electronic vehicle-stability functions.

For example, Jeep’s Wrangler JK documentation describes an Electronic Brake Control system that includes ABS, Electronic Brake Force Distribution, Brake Assist, Traction Control, Electronic Stability Control, and other functions working together.

If your steering wheel is significantly off-center after suspension or steering work and ABS/ESC-related warnings appeared at the same time, the steering-angle and alignment side of the system may need diagnosis.

This is particularly relevant after installing suspension components, adjusting steering parts, or performing an alignment.

12. Incorrect Tire Size, Lift Kit, Or Suspension Modification

Modified Wranglers deserve extra attention.

Jeep specifically states in the JK owner’s guide that ABS is designed to operate with OEM tires and that modification may reduce ABS performance.

That does not mean every lifted Wrangler or Jeep with larger tires will automatically turn on the ABS light. It means modifications add variables that should be considered when a warning appears.

Check tire sizes, wheel-speed sensor wiring, steering alignment, suspension clearances, and anything recently changed.

Why Are The ABS And Traction Control Lights On In My Jeep Wrangler?

Seeing the ABS and traction-control lights together often points toward a problem affecting information shared by the electronic brake and stability systems.

A wheel speed sensor is a good example. The information is useful not only for anti-lock braking but also for systems that manage wheel slip and stability. AutoGuru notes that a failing Wrangler wheel-speed sensor may cause the traction-control warning to appear along with the ABS light.

Possible areas to investigate include wheel-speed sensors, sensor wiring, wheel hubs, electrical faults, and relevant stability-control inputs.

The key is to scan the correct control modules instead of assuming that two warning lights mean two separate broken parts.

Why Are My Jeep Wrangler ABS, ESP And BAS Lights On?

This warning combination is especially familiar to owners of some older Wrangler models.

ABS, Electronic Stability Control or ESP-related functions, Brake Assist, and traction-control systems share parts of the electronic brake-control network. Jeep’s JK documentation groups these functions together as part of its Electronic Brake Control system.

A wheel-speed problem can therefore have wider effects than simply illuminating the ABS light.

Steering-angle information, wiring problems, wheel-speed data, alignment, and related control-system faults may also need to be checked.

Do not replace a clockspring, steering-angle sensor, or ABS sensor solely because you found an online post with similar warning lights. Scan your Jeep first.

What Does “Service Antilock Brake System” Mean On A Jeep Wrangler?

If your Wrangler displays a message such as Service Antilock Brake System, treat it as a request for diagnosis rather than something to clear and forget.

The ABS controller has detected a condition that requires attention.

Newer Wranglers may also show stability-control warnings at the same time because modern brake and stability systems exchange information.

Your next step should be to retrieve ABS-related diagnostic trouble codes using a scan tool that supports the vehicle’s brake-control modules.

Why Are The ABS And Brake Warning Lights On Together?

This combination is more concerning than the yellow ABS light by itself.

On the Wrangler JK, Jeep states that the red Brake Warning Light may indicate problems such as low brake-fluid level or a hydraulic-system malfunction. It also states that the Brake Warning Light and ABS light can illuminate together during an Electronic Brake Force Distribution failure.

If both lights are on, do not treat the situation as a simple wheel-speed-sensor issue without inspecting the braking system.

ABS Light Only

The conventional brakes may still operate, but anti-lock functionality may be unavailable. Arrange diagnosis soon.

ABS And Traction Control Light

A fault affecting wheel-speed or stability-control information may be disabling more than one electronic assistance system.

ABS And Red Brake Light

Treat this combination more seriously. If braking feels different, the pedal is unusually soft, brake fluid is low, or stopping ability appears reduced, avoid continuing to drive and have the vehicle inspected.

Jeep’s JK guide warns that driving with the red brake warning illuminated can be dangerous and calls for immediate inspection.

Is It Safe To Drive A Jeep Wrangler With The ABS Light On?

If only the yellow ABS light is on and the regular braking system feels normal, your conventional brakes may continue to work. What you may not have is normal anti-lock assistance during emergency or low-traction braking. Jeep recommends servicing the system as soon as possible.

That does not make the warning safe to ignore.

Drive cautiously only when braking performance feels normal and there are no serious accompanying warnings.

Stop driving and arrange professional help if the red brake warning stays on, the brake pedal feels unusually soft or sinks, braking ability is reduced, you notice a fluid leak, or the vehicle behaves unpredictably during braking.

How To Diagnose A Jeep Wrangler ABS Light

A structured diagnosis can save a great deal of money because it prevents you from replacing parts based on guesses.

1. Note every warning on the dashboard. Record whether you have only an ABS light or ABS plus traction-control, ESC, brake, battery, or other warnings. Also note when the problem happens.
2. Check the basic brake condition. Verify brake-fluid level according to the correct procedure for your Wrangler and look for obvious brake-system problems.
3. Inspect all four tires. Check for mismatched tire sizes, unusual damage, very different inflation levels, or recent wheel and tire modifications.
4. Inspect the wheel-speed sensors. Look around each wheel for damaged components, contamination, loose connectors, or anything that changed recently.
5. Follow the sensor wiring. Look for stretched wires, broken clips, rubbing, corrosion, pinched harnesses, or loose plugs.
6. Check the wheel hubs and bearings. Investigate excessive play, noise, or damage that may affect the sensor signal.
7. Consider recent steering or suspension work. If the warning started immediately after an alignment, lift installation, steering adjustment, or axle work, inspect what was disturbed.
8. Check the electrical system. Inspect battery terminals and obvious grounds and test battery and charging-system condition if electrical symptoms are present.
9. Inspect the correct ABS fuses. Use the fuse information for your exact Wrangler year and trim.
10. Scan the ABS module. Retrieve stored and active ABS trouble codes and, where possible, compare live wheel-speed readings while diagnosing the fault.

Haynes also recommends retrieving diagnostic information and inspecting wheel-speed sensors and associated wiring during Wrangler ABS diagnosis.

Jeep Wrangler ABS Light On But No Codes: What Should You Do?

“No codes” does not always mean “nothing is wrong.”

The first question is whether your scanner can actually access the ABS controller.

A basic code reader intended mainly for engine emissions faults may not provide the ABS information you need. Use a scanner with ABS capability that supports your Wrangler’s model year.

If an ABS-capable tool still finds nothing, check for intermittent wiring faults and watch live wheel-speed values if the scanner supports them.

A sensor that fails only when the suspension moves or a harness that loses connection over bumps may be much easier to spot in live data than during a stationary inspection.

Common Jeep Wrangler ABS Trouble Codes

ABS codes vary by generation, year, control module, and exact fault, so a random internet code list is not the best way to diagnose your Jeep.

Instead, focus on the code description and affected circuit.

You may encounter faults involving a wheel-speed sensor circuit, implausible wheel-speed data, ABS pump or valve control, power supply, communication between modules, or other stability-control inputs.

Record the full code exactly as your scanner reports it.

Then verify the diagnostic procedure for your Wrangler’s year before replacing anything.

How To Tell Which ABS Sensor Is Bad On A Jeep Wrangler

The best method is to combine diagnostic codes with live wheel-speed data.

If three wheels report similar speeds while one repeatedly drops to zero or behaves erratically, you have a strong clue about where to inspect.

But that still does not prove the sensor itself has failed.

Inspect the sensor, connector, wiring, hub area, and signal source at that wheel.

Replacing all four sensors simply because the ABS light is on can waste both time and money.

How To Fix A Jeep Wrangler ABS Light

The correct repair depends entirely on what caused the warning.

A damaged wheel-speed sensor may need replacement. Broken sensor wiring should be properly repaired and protected. A failing hub or bearing needs the appropriate wheel-end repair. A steering or alignment problem requires correction rather than simply clearing the warning.

Electrical faults require circuit diagnosis.

ABS module, hydraulic-unit, or pump faults deserve especially careful testing because those components are more expensive and may require specialized procedures.

After the actual fault has been repaired, clear stored codes if necessary and confirm that the system completes its self-test without returning the warning.

How To Reset The ABS Light On A Jeep Wrangler

Do not make resetting the ABS light your first step.

Make it your last step.

The objective is not to make the dashboard look normal. The objective is to restore the system that caused the warning.

After a successful repair, some faults may clear after the system runs another successful self-check, while others may be cleared with an appropriate diagnostic scanner.

Haynes also describes clearing the warning after the underlying issue has been diagnosed and repaired.

Disconnecting the battery should not be treated as a repair. Even if a warning temporarily disappears, a genuine fault can return as soon as the control module detects it again.

Why Does My Jeep Wrangler ABS Light Come On And Off?

An intermittent ABS light often points toward a problem that is present only under certain conditions.

Loose connections and damaged wiring are worth checking first. Wheel-speed sensor signals may also become unreliable because of wheel-end problems.

Pay attention to patterns.

Does the warning appear when you turn?

Does it happen after hitting a bump?

Does it appear only when the Jeep is wet?

Did it start after wheel, suspension, brake, or axle work?

Does restarting the Jeep make it disappear temporarily?

These details can make diagnosis much faster.

ABS Light After Replacing A Wheel Bearing, Hub, Brakes, Or ABS Sensor

If the ABS light appeared immediately after repair work, inspect the area that was touched before assuming another component has failed.

Check whether the wheel-speed sensor connector is fully seated. Make sure the wiring was not pinched, stretched, or left rubbing against a moving part.

Verify that the installed hub or sensor is correct for the exact vehicle.

Then scan the ABS system and check whether the code points to the wheel that was serviced.

A warning that begins immediately after a repair is valuable diagnostic information.

ABS Light After Installing A Lift Kit Or Bigger Tires

Start by asking one question: Did the warning exist before the modification?

If the answer is no, inspect every part of the vehicle affected during installation.

Look at wheel-speed sensor wire routing and connector security. Check the steering wheel position and alignment. Verify the tire setup and make sure suspension components are not contacting wiring.

Jeep’s own JK guidance notes that ABS is designed around OEM tires and that tire modification can degrade system performance.

This does not mean larger tires automatically create an ABS fault. It means tire and suspension changes should not be ignored during diagnosis.

ABS Light After Off-Roading, Mud, Water, Or Trail Driving

Wranglers regularly encounter conditions that can expose wheel-end wiring and sensors to dirt, movement, and physical contact.

If the light appeared after a trail trip, inspect each wheel area before replacing anything.

Look for a pulled connector, damaged retaining clip, wire caught by a suspension component, heavy contamination, or impact damage around the hub and sensor area.

Clean only with methods appropriate for the component. Avoid aggressive probing or damaging electrical connectors while investigating.

How Much Does It Cost To Fix A Jeep Wrangler ABS Light?

The answer depends on the cause.

A sensor or wiring repair can be relatively inexpensive compared with replacing a hub assembly, ABS hydraulic unit, or control module.

As a current U.S. reference, RepairPal estimates a Jeep Wrangler wheel-speed-sensor replacement at roughly $182 to $226, before taxes, fees, location differences, or additional repairs. Another U.S. mobile-repair estimate is lower, which shows why location and service provider matter.

In Australia, AutoGuru currently gives a broader Jeep ABS/wheel-speed-sensor replacement range of about A$375 to A$600, depending on the vehicle and repair circumstances.

UK replacement-sensor parts can be inexpensive in the aftermarket, but the final installed price depends heavily on diagnosis, labour, seized components, and the exact Wrangler generation.

For Canada, as well as the UK, USA, and Australia, use local pricing for the final repair decision instead of simply converting another country’s estimate. Dealer labour, independent-shop labour, taxes, parts availability, and corrosion can change the bill considerably.

The most economical approach is usually diagnose first, buy parts second.

Jeep Wrangler ABS Problems By Generation

Jeep Wrangler TJ ABS Light

TJ models are older now, so age-related wiring, connectors, corrosion, previous repairs, and wheel-end condition deserve close inspection.

Do not assume a repair procedure written for a JK or JL applies directly to a TJ.

Jeep Wrangler JK And JKU ABS Light

JK and JKU owners may encounter ABS warnings alongside traction- or stability-control warnings because these functions are part of the broader electronic brake-control system.

The 2018 JK documentation confirms that ABS, EBD, Brake Assist, Traction Control, ESC, and other functions operate within that system.

Wheel-speed sensors, wiring, wheel hubs, modifications, and electrical faults are all reasonable places to investigate.

Jeep Wrangler JL And JLU ABS Light

JL and JLU models use newer electronic architectures, so module communication and proper scan-tool support become even more important.

If the Jeep shows a text warning such as Service Antilock Brake System, scan the relevant control systems before replacing parts.

Jeep Wrangler 4xe ABS Warning

A Wrangler 4xe combines conventional braking hardware with a more complex electrified vehicle platform.

Treat brake and ABS warning messages seriously and use model-specific service information. Do not use procedures written for a non-hybrid JK simply because both vehicles have an ABS warning light.

DIY Fix Or Mechanic: Who Should Repair It?

Basic inspection can be DIY-friendly if you are comfortable working safely around vehicles.

You can check warning-light combinations, tire condition, visible wheel-speed sensor wiring, loose connectors, battery terminals, and signs of recent physical damage.

A scan tool can also make basic diagnosis much easier.

Professional help is the better option when the red brake warning is illuminated, hydraulic braking is affected, you cannot communicate with the ABS module, internal ABS pump or module faults are suspected, or the diagnosis requires electrical testing you are not comfortable performing.

Brake-system safety is not a good place for trial-and-error repairs.

How To Prevent Jeep Wrangler ABS Problems

You cannot prevent every electrical or mechanical failure, but routine inspection helps.

Check exposed wiring after difficult off-road trips. Pay attention to new noises from wheel bearings or hubs. Make sure sensor harnesses remain properly clipped after suspension or brake work.

If you modify the suspension, steering, wheels, or tires, inspect nearby wiring and confirm that the Jeep drives straight with the steering correctly centered.

Most importantly, investigate an ABS warning when it first appears instead of waiting for additional warning lights.

Frequently Asked Questions About Why Is My ABS Light On In My Jeep Wrangler

Why Did My Jeep Wrangler ABS Light Suddenly Come On?

The ABS controller has detected a fault. A wheel-speed sensor or its wiring is one possible cause, but wheel-end, electrical, module, hydraulic, and other control-system problems can produce the same warning. Scan the ABS module before replacing parts.

Why Are My ABS And Traction Control Lights On?

The ABS and traction-control systems use related vehicle information. A wheel-speed signal fault, for example, can affect both systems and illuminate both warnings.

Why Are My ABS, ESP And BAS Lights On?

Several brake and stability functions operate within the Wrangler’s electronic brake-control system, particularly on JK models. A fault that affects shared information can therefore trigger multiple warnings.

Can A Bad Wheel Bearing Cause The ABS Light?

A wheel-end problem can affect the wheel-speed sensing system, depending on the design and nature of the failure. Inspect the hub, bearing, sensor, wiring, and signal source rather than replacing the sensor automatically.

Can Low Brake Fluid Cause The ABS Light?

Low brake fluid is particularly important when the red Brake Warning Light is also illuminated. Jeep documentation identifies low fluid and hydraulic faults as possible reasons for the red brake warning.

Can A Weak Battery Cause The ABS Light?

Low or unstable voltage can contribute to electrical and control-module faults. Check battery and charging condition when the ABS warning appears with other electrical symptoms, but test before replacing the battery.

Can A Bad Clockspring Cause ABS Or Stability-Control Warnings?

Steering-related inputs can affect stability-control operation on some configurations, but a clockspring should not be diagnosed solely from dashboard lights. Retrieve the relevant codes and test the affected system.

Why Is My Jeep Wrangler ABS Light On After A Lift?

Inspect anything disturbed during the lift installation, especially wheel-speed sensor wiring, connectors, steering alignment, and suspension clearances. Also consider the tire and wheel changes made at the same time.

Why Is My ABS Light On After Replacing A Wheel Bearing?

The sensor or its wiring may have been disturbed, the replacement component may not be correct, or the original fault may still exist. Scan the ABS module and inspect the wheel that was serviced.

Why Is My ABS Light On But There Are No Codes?

Make sure your diagnostic scanner supports ABS codes. A basic engine-code reader may not provide the brake-control information required for proper diagnosis.

How Do I Know Which ABS Sensor Is Bad?

Use an ABS-capable scanner to read fault codes and, ideally, compare live wheel-speed data from all four wheels. Then inspect the sensor circuit at the wheel showing abnormal information.

Will The ABS Light Reset Itself?

It may go out after the fault is corrected and the system passes its checks, depending on the model and type of fault. Some stored faults may need to be cleared with a suitable scan tool.

Can I Reset The ABS Light By Disconnecting The Battery?

Disconnecting the battery may clear some stored information on certain vehicles, but it does not repair the cause of an ABS fault. If the problem remains, the warning can return.

Can I Drive My Jeep Wrangler With The ABS Light On?

If only the yellow ABS light is illuminated and conventional braking operates normally, Jeep documentation indicates the regular brake system can remain functional, but the anti-lock portion may not work and service is recommended as soon as possible. If the red brake warning is also on or braking feels abnormal, treat the problem as more urgent.

How Much Does It Cost To Replace A Jeep Wrangler ABS Sensor?

The amount varies by country, model year, labour rate, and which sensor is required. RepairPal currently estimates roughly $182–$226 for a Wrangler wheel-speed-sensor replacement in the U.S., while Australian repair pricing can be considerably different.

Final Thoughts

When you are asking, “Why is my ABS light on in my Jeep Wrangler?”, do not jump straight to the most expensive possibility.

Start with the warning lights and symptoms. Scan the ABS controller. Inspect the wheel-speed sensors, wiring, hubs, tires, and recent repair or modification work. Then use the diagnostic results to decide what actually needs fixing.

A wheel-speed sensor may be the answer, but it is not the only answer.

And remember the important safety distinction: a yellow ABS warning generally means the anti-lock function needs service, while an ABS warning accompanied by a red brake-system warning deserves much more immediate attention.