* Faulty ABS Wheel Speed Sensor: This is the most common cause. The sensors monitor the rotation speed of each wheel. If a sensor is dirty, damaged, or malfunctioning, it sends incorrect signals to the ABS module, triggering the light. This is often due to corrosion, broken wires, or physical damage.
* Bad ABS Module: The ABS module is the "brain" of the system. It receives signals from the wheel speed sensors and controls the ABS pump. A faulty module can cause various issues, including the ABS light illumination. This is a more expensive repair.
* Low Brake Fluid: While seemingly unrelated, critically low brake fluid can trigger the ABS light because the system shares fluid with the regular braking system. Check your brake fluid level.
* Faulty ABS Pump: The pump is responsible for applying pressure to the brakes during ABS operation. A malfunctioning pump can cause the light to illuminate.
* Wiring Problems: Damaged or corroded wiring between the sensors, the module, and the pump can disrupt the system and trigger the light. This often occurs in areas exposed to the elements.
* Corroded Connections: Connections at the sensors, the ABS module, and the pump can corrode, leading to poor electrical contact and ABS system malfunctions.
Troubleshooting Steps (In order of easiest to hardest/most expensive):
1. Check Brake Fluid: The simplest first step. Low fluid suggests a leak somewhere in the brake system – this should be addressed immediately regardless of the ABS light.
2. Visually Inspect Sensors and Wiring: Look for any obvious damage to the wheel speed sensors (located near the wheel hubs) and their wiring harnesses. Look for corrosion, broken wires, or anything out of the ordinary.
3. Have the ABS System Scanned: The most reliable way to diagnose the issue is to have a professional scan the ABS module using an OBD-II scanner that can read ABS codes. This will provide specific error codes that indicate the faulty component. An auto parts store often offers this service for free.
4. Professional Diagnosis and Repair: If you can't identify the problem yourself after scanning, take your Ranger to a qualified mechanic specializing in ABS systems or a trusted repair shop. They have the tools and expertise to diagnose and repair the issue efficiently.
Important Note: Driving with a malfunctioning ABS system doesn't necessarily mean your brakes won't work, but it *does* mean that the anti-lock braking function is disabled. This can be dangerous in slippery conditions. Get it checked out as soon as possible.
