Jeep ABS Lights On – Causes, Symptoms, and Fixes

If you own a Jeep and notice the ABS light on your dashboard is on, it can be a frightening sight. Knowing the common causes of the ABS light turning on can save you time and money. This article got you covered. We’ll tackle the common causes, ranging from simple sensor malfunction to a more complex problem with the control module. 

What does the ABS light mean on a Jeep? 

The Anti-lock Braking System (ABS) in your Jeep Wrangler, Cherokee, Renegade, and other models is a safety feature that reduces the braking distance when the driver suddenly engages the brakes. The ABS regulates the hydraulic braking pressure to prevent the brakes from locking up. When the ABS faults within the system, the ABS light turns on to alert the driver that a fault needs attention. It is important to determine and fix the problem immediately to ensure the operability of the ABS.

Symptoms

• ABS Light Stays On 
• ABS and Traction Control Warning Lights – are both always ON
• ABS and Traction Control Warning Lights – come ON and OFF intermittently
• ABS, EPS, BAS, 4WD, and Traction Control Warning Lights – are simultaneously ON

Common Causes

Faulty ABS Speed Sensor

The ABS relies on wheel speed sensors to detect the speed of each wheel and send signals to the ABS module. The ABS module uses this information to determine if any wheel is about to lock up and regulates the brake pressure.

If one or more wheel speed sensors are damaged, it can affect the ABS and turn on the ABS light. Common issues that can cause a faulty ABS speed sensor include damage, wear, or contamination from dirt, debris, or metallic particles. The ABS speed sensors are located near the wheels, and exposure to extreme road conditions can cause them to malfunction. 

Malfunctioning ABS Module

The ABS module is the brain of the ABS, responsible for monitoring the wheel speed sensors and adjusting the hydraulic braking pressure. If the ABS control module fails, it can cause the ABS light to turn on. 

A malfunctioning ABS module can cause the ABS to activate randomly or fail to engage when needed, leading to reduced braking performance. Common issues that can cause a malfunctioning ABS control module include corrosion or moisture damage, overheating, electrical issues, or a failure of internal components.

Weak Battery 

A weak battery cannot supply the needed battery power to the entire ABS. This can lead to the ABS not functioning properly and the ABS light turning on. Sensors can also send inaccurate data to the ABS module and randomly activate the brakes while driving. It is important to ensure the battery voltage is between 12.6 and 12.8 volts for the ABS to work properly.

Broken ABS Tone/Reluctor Rings

The ABS wheel speed sensors use tone rings to detect the speed of each wheel. The tone ring is a toothed ring located in the wheel hub that rotates with the wheel. When a tone ring is damaged or clogged with dirt, it prevents the wheel speed sensor from reading the wheel speed, thus turning the ABS light on.

The ABS tone rings can become damaged or broken for various reasons, such as exposure to harsh road conditions, extreme temperatures, or impacts from road debris. Additionally, improper installation of the tone ring during routine maintenance or repairs can also cause it to become damaged.

Broken or Damaged Wires and Connectors

The ABS relies on wires to send and receive data between the ABS modules and various sensors. If wires or connectors become damaged, corroded, or broken, it can cause a signal loss and trigger the ABS warning light.

Wires and connectors are prone to dirt, debris, and harsh weather conditions. This can wear them out and cause a signal loss. If there is no physical damage to the wires, a simple connector cleaning can sometimes resolve the ABS light.

Blown out Fuse

The ABS uses fuses as a safety device to protect the ABS from the sudden flow of electricity. If a fuse is blown, it can affect the operation of the ABS and trigger the ABS warning light. When a fuse is blown, the system has a short circuit. It is important to know the cause before replacing the fuse. 

Low brake fluid level

The ABS uses the brake fluid to regulate the hydraulic braking pressure. If the brake fluid falls to a low level, the ABS cannot regulate the pressure properly, resulting in a spongy brake pedal and the ABS light turning on. 

The brake fluid decreases due to the wearing out of brake pads and if there is a leak in the system. Knowing the problem’s cause is important to avoid brake failures while driving. 

Low Tire Pressure

Low tire pressure can also cause your ABS light to turn on. The wheel’s circumference decreases with low pressure, causing it to move slower than other tires. The wheel speed sensor can detect the change in wheel speed, causing the ABS to activate. Maintaining the correct tire pressure is important to avoid accidents while driving.

Dirt and Debris

Jeep is well known for its off-road capabilities. It can drive through rough terrain easily. But this can cause problems when the vehicle is not cleaned properly. Dirt and mud can accumulate in the sensors, and the tone rings, preventing the ABS module from reading the wheel speed and thus turning on the ABS light.

It is important to thoroughly clean the vehicle, especially under it, to ensure no mud build-up that can cause problems. Cleaning under the vehicle can also reveal damaged parts, like brake lines and sensors, that can cause the ABS light to turn on. 

Recall in ABS System

Several Jeep models have been affected by recalls due to a defective ABS module. Here are some models affected:

1. Jeep Grand Cherokee (2014-2015)
2. Jeep Wrangler (2007-2010) 
3. Jeep Liberty (2006-2007)

It is encouraged to contact the Jeep service center if your vehicle is affected by the recall. To check if your vehicle is affected, click here. 

Troubleshooting & Reset Procedure

To find exactly why the ABS light is on in your Jeep, use the YOUCANIC scanner to run a full vehicle health check. The codes present will point you to the faulty ABS wheel speed sensor or any other issue that is triggering the ABS light on your Jeep.

1. Locate the OBD II port under the dash of your vehicle. It is usually located near the driver’s side and is a 16-pin connector.
2. Plug in the scanner and turn on the ignition, but do not start the engine.
3. Select the make of your vehicle from the list of available makes. You can select “Auto Detect VIN” to automatically detect your vehicle’s make and model.
4. Select “Control Units,” then “ABS/Traction Control Module.” Remember that the name of this module may vary depending on the make and model of your vehicle.
5. Once the scanner is on, select “Diagnostics” from the main menu.
6. Once you have selected the ABS/Traction Control Module, you can select “Read Codes” to see any stored trouble codes related to the ABS. The scanner will display the current codes, which will help you determine what may be causing the ABS and traction control warnings to turn on.
7. Based on the codes, the scanner may suggest performing further tests or inspecting certain components of the ABS, such as the wheel speed sensors, brake lines, and hydraulic control unit.
8. Once the underlying issue has been fixed, then select Clear Codes to clear fault codes stored in the ABS control unit and reset ABS and traction control warning lights.

Fault Codes

• C1015 – Right Front Wheel Speed Sensor Circuit
• C1016 – Left Front Wheel Speed Sensor Circuit
• C1020 – Right Rear Wheel Speed Sensor Circuit
• C1021 – Left Rear Wheel Speed Sensor Circuit
• C102B – Right Rear Wheel Speed Comparative Performance
• C1035 – Left Front Wheel Speed Comparative Performance
• C1041 – Right Front Wheel Speed Comparative Performance
• C1051 – Left Rear Wheel Speed Comparative Performance
• C121C – ABS Hydraulic Pump Motor Circuit
• C2202 – Anti-Lock Brake Module Internal