* Wheel Speed Sensor(s): This is the most common cause. These sensors monitor each wheel's speed. A faulty sensor sends incorrect data to the ABS module, triggering the warning lights. Dirt, damage to the sensor itself, or wiring problems are common culprits.
* ABS Module: The ABS module is the "brain" of the system. Internal failures within the module can cause it to malfunction and illuminate the warning lights. This is often a more expensive repair.
* Wiring Issues: Damaged or corroded wiring in the ABS system can disrupt communication between the sensors, module, and other components. This is particularly common in older vehicles like the Terraza.
* Low Brake Fluid: While less likely to directly trigger the ABS and traction control lights, critically low brake fluid can indirectly cause issues and lead to the warning lights. Check your brake fluid level as a first step.
* Brake System Problems: Severe issues within the main braking system (like a leak or worn components) *can* sometimes trigger these lights as a secondary effect.
What to Do:
1. Check Brake Fluid: This is the easiest and quickest check. Low fluid needs immediate attention.
2. Have it Diagnosed: The most reliable way to determine the exact cause is to have a qualified mechanic diagnose the problem using an OBD-II scanner capable of reading ABS codes. This scanner will give specific trouble codes that pinpoint the faulty component. Ignoring the lights can lead to impaired braking performance.
3. Don't Ignore the Lights: Driving with these lights on means your ABS and traction control are disabled, potentially compromising safety, especially in adverse conditions.
In short, while several factors could be at play, a proper diagnostic scan by a mechanic is essential to identify the root cause and effect the necessary repair.
