ABS and Traction Control Light On? (14 Reasons Why)

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Whenever your vehicle needs maintenance or wants to tell you that something is wrong, it may trigger the ABS and Traction Control lights. The reasons why they come on are usually not a source for worry, but they should not be ignored. What would cause the ABS and traction control light to come on?

When the ABS and Traction Control lights illuminate, it is typically due to a faulty wheel or speed sensor or an ABS module failure. An OBDII scanner can read trouble codes stored in the ECU, but you need a mechanic to test these codes to identify the cause and corresponding fix for the issue.

Here are 14 reasons why the ABS and traction control lights come on:

  1. ABS module failure
  2. Computer issues
  3. Blown fuse
  4. Dysfunctional wheel-speed sensor
  5. Low tire pressure
  6. A defective steering angle sensor
  7. Low brake fluid
  8. Faulty steering rack
  9. Defective pump and valve
  10. Bad wheel alignment
  11. Dirt and debris
  12. Low battery voltage
  13. Limp mode
  14. Turned-off Traction control

When one or both warning lights come on, be ready to do some in-garage diagnostics or get your vehicle to a shop pronto. This guide covers what would cause the ABS and Traction Control light to come on, how to fix the problem, and when to get professional assistance. Continue reading to learn more.

ABS and Traction Control Defined

Instrument Cluster Person Driving

Anti-lock Braking System (ABS)

ABS is a safety feature used on aircraft and land vehicles. Its light usually gives off a yellow, amber, or orange color and comes on for a few seconds as part of your vehicle’s system check each time you turn on the engine. It did not come standard in cars until September 1, 2013, when the National Highway Traffic Safety Administration or NHTSA mandated cars to have Electronic Stability Control or ESC, which prevents wheel lock under braking and alters the front-to-rear brake bias.

The ABS provides the driver with steering control when it senses the vehicle entering an uncontrollable skid. With this anti-skid feature, wheel-mounted sensors monitor the speed at which the wheels are turning. And if it detects that one wheel turns slower than the others during braking, it will interpret this as a lock-up or a potential cause for loss of steering control. ABS would immediately intervene by quickly pumping the brakes at the outlier wheel, allowing it to spin, and giving back the driver braking and steering control.

Traction Control System (TCS)

On the other hand, Traction Control is a system that monitors your vehicle’s stability and steering performance. It keeps track of historical data on how your car grips the road and draws across its surface. If it detects anything outside of the usual patterns based on these historical data, it proactively finds the potential error and fixes it. It spurred the requirement for ABS and is an essential part of vehicle safety.

Like ABS, Traction Control uses wheel-speed sensors to detect if any wheel has lost traction. You will easily know this by its light, which could be a flashing Traction Control symbol, a counterclockwise arrow around a triangle with an exclamation point, or a picture of a car losing control. Once it does, it triggers a hydraulic modulator to slow down or stop the wheel spin. This feature comes into play in snowy or icy conditions, where one or more of your vehicle’s drive wheels can spin due to the slippery surface. The Traction Control System piggybacks on ABS, using the same wheel-speed sensors to detect tire slip during acceleration.

ABS and Traction Control Light On? (14 Reasons Why)

ABS and Traction Control Light On

Knowing what prompts warning lights to go off is a must if you want to address the problem. In this section, we will cover what would cause the ABS and Traction Control Light to come on with brief descriptions for each (corresponding trouble codes store in your vehicle’s PCM/ECM/ECU):

1. ABS Module Failure

The simplest yet most common reason one or both warning lights may come on. The ABS controller could have just stopped working. Or a brake system malfunction, say an unresponsive brake pedal, may have caused the Traction Control Light to come on. It is bound to happen since the ABS and Traction Control systems share the same control module and vehicle components.

2. Computer Issues

Your vehicle’s central computer system plays a vital role in proper Traction Control function by taking over the said system. So, if your Traction Control Light goes off and you find no external factor affecting the Traction Control System, then chances are the computer system itself is having problems. The central computer or PCM can get errors or reprogram to get rid of issues in its current programming.

3. Blown Fuse

If your ABS light comes on, it could indicate a blown fuse or a broken wire between the controller and the system sensors. The ABS Light activates once your car’s computer detects this problem. If a fuse blows, the PCM picks up the signal and activates the ABS light, along with the Check Engine Light, to notify you that a problem has occurred. When this happens, have your vehicle scanned for codes to help pinpoint the specific cause.

4. Dysfunctional Wheel-Speed Sensor

The ECU sees an incorrect reading and turns the ABS light on when your wheel speed sensor fails. If you suspect this to be the reason your ABS light goes off, check that you do not have low brake fluid, that your wheel-speed sensor is not damaged or covered in grime, and that all tires match. Otherwise, this problem will occur and will most likely trigger your ABS light. If your brake fluid and tires check out, then scan your car’s brake control module for codes to help figure out the issue. If you do not have a computer scan tool, then have a certified mechanic, do the scanning for you.

5. Low Tire Pressure

Your car has sensors that monitor wheel speed and constantly relay information to the ABS and Traction Control system. When any of your tires have low tire pressure, the ECU ends up sensing an abnormal speed. It may send off inaccurate or flawed information to the ABS or Traction Control, which inadvertently activates their warning signals.

6. A Defective Steering Angle Sensor

The steering angle sensor is found inside the steering column and is essential for accurately measuring the steering wheel’s angle, position, and the rate at which it returns. If its wiring becomes faulty, it will adversely affect the connection between the Traction Control System computer and the wheel, resulting in its failure to compute and process information correctly and triggering the Traction Control Light to illuminate.

7. Low Brake Fluid

Low brake fluid level may cause your vehicle to drive a little differently. Hence, the braking system may feel soft or spongy, causing your car to take more time to come to a complete stop. Aside from the ABS light, you are also likely to get other system indicators. Using the correct fluid type for your four-wheeler is one way to prevent this occurrence. If you already do but still get low brake fluid readings, check for any leaks in the entire brake and ABS systems. Make sure to address immediately (if you find any) as it could be quite dangerous if left unattended.

8. Faulty Steering Rack

The steering rack is one of the most essential components of your car that receives high-pressure hydraulic fluid and helps drivers direct the wheel easily. If this becomes faulty, drivers will have trouble with handling, especially on rough terrain. Although uncommon, this is one place vehicle owners should consider checking if the Traction Control Light illuminates.

9. Defective Pump and Valve

This pump-and-valve system works together with your vehicle’s wheel-speed sensor. When this system goes bad, the wrong amount of brake fluid pressure applies to each wheel, messing up the anti-lock mechanism. Often accompanied by a red warning light when regular brakes come on, this indicates that your car suffers brake fluid loss or has worn-out brakes. Either root problem requires immediate attention and possible repair work.

10. Bad Wheel Alignment

The turning of your wheels can become inconsistent in icy situations where you unintentionally bump your vehicle. Or if your car has had too many encounters with curbs and potholes. When this happens, ABS or Traction Control will apply to the wheels getting an insufficient amount of pressure. If something prevents these systems, then warning lights will come on and remain on until the issue rectifies. If the issue is just momentary, then the light will reset by itself. Otherwise, it will be indicative of a bigger problem.

11. Dirt and Debris

Salted roads and dusty areas get onto your four-wheeler’s Traction Control system and prevent it from properly functioning. In turn, this causes the warning light to go on and stay on. The only way you can reset the Traction Control Light and get the system to do its job again is to clean it yourself or have a carwash do it for you. If cleaning does not help, stop by your local mechanic or parts store, and ask for advice.

12. Low Battery Voltage

A weak battery or one with low voltage can inadvertently cause other warning lights to come on, including the ABS and Traction Control lights. When your car’s alternator is not working properly, the occurrence may cause the battery to lose charge and the car losing all power. And since the ABS and Traction Control System both rely on ECU, which needs power to work, an abrupt loss of power may send wrong signals to both systems that could cause their respective warning lights to go off.

13. Limp Mode

The limp mode (or limp home mode) is a self-preservation security feature in cars that activates when it detects abnormal readings or a malfunctioning electrical component or mechanical operation. For instance, your car starts acting up and behaving erratically. When these abnormalities happen, the warning lights on your dash (including ABS and Traction Control lights) illuminate, car features keep to a bare minimum with extras turned off or reduced, and transmission, speed, and RPM are limited.

14. Turned-off Traction Control

One of several things could happen – you deliberately turn off Traction Control as you do not drive on slippery surfaces often, you are stuck in deep mud or snow, and do not need Traction Control for getting yourself unstuck, or you unknowingly did so. Either way, a deactivated Traction Control will turn on the corresponding warning light as a result. If you turned it off intentionally, you should not be surprised when the warning light comes on. Otherwise, refer to your service manual to turn it back on, or seek professional help if this does not work.

For Traction Control issues, getting them repaired is not as crucial as ABS, considered of higher importance. However, these issues are not to be dismissed. Traction Control takes the place of limited-slip differentials in some vehicles – having it disabled makes for an arduous tire slippage control.

All these issues can be stored in the PCM/ECM/ECU either as a pending, confirmed, or permanent code and would require a more advanced OBDII scanner to read the code and decipher the root cause of the problem. They may also trigger only one or both warning lights.

Can I Ignore These Warning Lights?

You should never disregard the warning if one or both the ABS and TCS lights come on. It is especially unsafe to drive if both indicators are lit, along with the red brake warning light, as this signifies a serious problem with your braking system. For either scenario, find a safe place to pull over if you are on the road, then do a quick vehicle restart to see if the lights will reset. This step should help you rule out if it is only a fluke that triggered the warning lights. However, if it comes back on, do not continue driving but call a mechanic and get a system diagnosis instead. If the need to continue driving is urgent, make sure that you do so gently while avoiding hard braking or acceleration, as these could trigger wheel slippage.

How to Reset the ABS and TCS Light

After determining what would cause the ABS and Traction Control Light to come on and fixing the problem, you need to reset the lights to ensure that your vehicle’s safety features are functional and ready to go off in the event of another skid/slippage happens. Here are steps on how you would do the reset for each of these warning lights:

ABS Light

  1. When resetting the central computer or PCM/ECM, disconnect the positive cable from the car battery, then hold down on the brake pedal – this will drain the vehicle’s electrical system. Plug the positive cable back in to restore power. This step should turn the light off for at least a week if it does not permanently reset it.
  2. If the light appears after doing step 1, check for worn-out ABS sensors and change them by unscrewing their wheel-hub-mounted housing, unplugging the wire, and attaching replacement sensors. Make sure to reset the computer again after completing this step.
  3. Should the light persist after doing steps 1 and 2, connect an OBDII reader to your vehicle’s diagnostics system to trace down what is prompting the warning light to turn on. Note that other parts relating to brakes may be setting the light off and may require replacement or repair.

TCS Light

  1. Just like the Check Engine Light (CEL), vehicle sensors recheck the problem that triggered the Traction Control Light and turns the TCS light off once it recognizes that the issue has been addressed. If your TCS or stability light is still on after repair, then drive the car for a few minutes to give the vehicle’s computer enough data to assure it that traction is okay.
  2. Since you can manually override the Traction Control Light in instances where you need to get unstuck from deep snow or mud, then do not forget to turn it back on. Likewise, note that the TCS light stays on when the stability control system is deactivated, so ensure that the other feature is on as well.
  3. For the wheel-speed sensors to get accurate readings, all wheels will have to be of the same size and type – this will prevent uneven spinning, which may trigger the Traction Control Light inadvertently.
  4. Since the Traction Control System is mated with your vehicle’s stability program, driving too fast is guaranteed to activate the TCS light. Driving moderately and keeping the car under control will help turn off the warning light.
  5. Should the first four steps be unsuccessful at resetting your vehicle’s TCS light, then use an OBDII scanner and run a system check on your car to ensure that nothing is malfunctioning. For best results, bring your vehicle to a professional mechanic for thorough scanning.

Cost for Fixing My ABS and TCS Lights

There is no specific ballpark figure for repair costs since the reasons your light comes on can be varied. However, the diagnostic test a mechanic needs to perform can cost anywhere between $60 and $1,000. It depends on your location and mechanic of choice (exclusive of taxes and other fees). You can preview the potential problem yourself using a make-specific OBDII scanner. Sophisticated systems usually work with an app that you need to install on your mobile or smartphone.

Best ABS/TCS Code Readers

OBDII scanners that can pull codes of what would cause the ABS and Traction Control Light to come on can be quite expensive and are not the same as typical generic code readers you can buy for $30 or less. As such, it would make perfect sense to purchase an OBDII scanner that will give you your money’s worth and be able to perform a myriad of functions. Here is a list of my top five recommendations:

  • Innova CarScan Pro 3100/3150e/5210/5610
  • Ancel AD310/ BD310
  • BlueDriver LSB2
  • Autel AutoLink AL539/AL319/ AL519/DS808
  • BAFX Products Car Diagnostic Tool

Conclusion – ABS and Traction Control Light On

The ABS and Traction Control lights come on whenever the vehicle’s computer or PCM detects a malfunction, a faulty wheel sensor, or other mechanical failures. These warning lights do not imply anything severe by themselves but may point to a graver problem when paired with the main brake light going off.

To summarize, here are 14 reasons why the ABS and traction control lights come on:

  1. ABS module failure
  2. Computer issues
  3. Blown fuse
  4. Dysfunctional wheel-speed sensor
  5. Low tire pressure
  6. A defective steering angle sensor
  7. Low brake fluid
  8. Faulty steering rack
  9. Defective pump and valve
  10. Bad wheel alignment
  11. Dirt and debris
  12. Low battery voltage
  13. Limp mode
  14. Turned-off traction control

Should these lights illuminate while you are driving, do not panic as your car’s braking system will still work. Just make sure to slow down and do moderate braking so as not to trigger any wheel slippage. One best practice in dealing with this situation is to have your OBDII scanner handy. This would help you pull codes, identify triggers, and get the ABS and TCS lights turned off. But if resetting the warning lights is not feasible, bring your vehicle to a mechanic for thorough diagnostics and repair.

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