Most Common Causes:
* Low Brake Fluid: This is the simplest and easiest check. Low brake fluid can trigger the ABS light because it indicates a potential leak in the brake system. Check the brake fluid reservoir and top it off if necessary. However, *if* the fluid is low, *find the leak* immediately as it's a serious safety issue.
* Faulty ABS Wheel Speed Sensor: These sensors monitor the speed of each wheel. A faulty sensor will send inaccurate information to the ABS module, triggering the light. They're prone to damage from debris, corrosion, or physical impact. This is a frequent culprit.
* ABS Module Failure: The ABS module is the "brain" of the system. Internal failures within the module can cause the light to illuminate. This is a more costly repair, often requiring replacement.
* Faulty ABS Pump Motor: The ABS pump is responsible for modulating brake pressure during ABS activation. A failed pump can cause the light to stay on.
* Wiring Problems: Damaged, corroded, or loose wiring in the ABS system can interrupt signals and trigger the light. This often involves the wheel speed sensors' wiring.
Less Common Causes:
* Brake Pressure Switch: A problem with this switch, which monitors brake pedal pressure, can also trigger the ABS light.
* Faulty Brake Light Switch: While usually resulting in a brake light issue, it can sometimes affect the ABS system.
Troubleshooting Steps (In Order):
1. Check Brake Fluid Level: This is the first and easiest step.
2. Visual Inspection: Check for any obvious damage to wiring harnesses, especially around the wheels. Look for corrosion, cuts, or loose connections.
3. Scan the OBD-II Codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs). These codes will pinpoint the specific problem area. An inexpensive scanner from an auto parts store is sufficient.
4. Professional Diagnosis: If you're uncomfortable performing more complex troubleshooting, take your Explorer to a qualified mechanic or an auto repair shop. They can accurately diagnose the problem and perform the necessary repairs.
Important Note: Driving with a malfunctioning ABS system is possible, but it significantly reduces the effectiveness of the anti-lock braking system. This means you may lose control of your vehicle during emergency braking, especially on slick surfaces. Address the ABS light as soon as possible for safety.
