Mitsubishi Pajero IV ABS Light Stays On: Don't Ignore That Wheel Speed Sensor

What a steady ABS light really means

When the ABS light stays on continuously on your Mitsubishi Pajero IV, the ABS control module has detected a fault and disabled the anti-lock braking system. Your normal brakes still work, but you lose ABS, and often traction control and stability control as well. The most common culprit is a wheel speed sensor at one of the four wheels — it can be dirty, damaged, or have a broken wire. Less often, the problem is the tone ring (reluctor ring) on the hub, a corroded connector, or the ABS module itself.

Which parts to check first

Start by scanning the ABS module for fault codes. That will tell you which wheel the module is unhappy with, saving you from guessing. Once you know the corner, inspect these in order:

• Wheel speed sensor and its connector — look for chafed wires, corrosion, or a sensor that's covered in metal debris.
• Tone ring — check for cracks, missing teeth, or heavy rust. A cracked ring gives an erratic signal.
• Sensor air gap and mounting — a loose sensor or excessive wheel bearing play can cause the signal to drop out.
• Wiring harness — flex the harness while watching live data; intermittent faults often hide in the loom near the wheel arch.

If the sensor and ring look fine, a scope or live data check can confirm whether the sensor is actually producing a clean AC signal. Don't just replace parts blindly — a $20 sensor is easy, but a misdiagnosed ABS module is expensive.

Is it safe to keep driving?

Yes, you can usually drive carefully, but you should treat the Pajero as a car without ABS. That means longer stopping distances on wet, gravel, or icy roads, and no emergency braking assistance. If the brake warning light is also on, the pedal feels spongy, or you hear grinding, stop driving and get it towed. Otherwise, book a diagnostic scan soon — a simple wheel speed sensor fault is often a quick, inexpensive fix that restores your safety net.

This material is AI-generated and for informational purposes only — it does not replace an in-person diagnosis by a qualified mechanic.