GMC Yukon ABS Light On: Wheel Speed Sensor Fault?

If the ABS warning light in your GMC Yukon V stays on from the moment you start it, the anti-lock braking system has logged a fault and disabled itself. That does not mean your brakes are gone — you still have normal hydraulic braking. But you have lost ABS and often traction/stability control. The most common culprit on these trucks is a wheel speed sensor, but do not just throw a sensor at it. A proper scan and live data check will save you time and money.

Most likely causes

• Wheel speed sensor — dirt, metal debris, moisture, or internal failure can drop the signal. Front sensors are common because of steering and brake heat.
• Wiring or connector — the harness near the wheel can rub, corrode, or break internally. Look for green crust, chafing, or a loose pigtail.
• Tone ring or reluctor ring — cracked, rusted, or packed with debris, so the sensor cannot read wheel speed.
• Hub bearing play — worn wheel bearings change the air gap and trigger the light.
• ABS module or pump — less common, but possible if sensors, wiring, and rings check out.

Check first: scan all ABS codes with a capable scan tool, then look at live wheel-speed data while driving slowly. A sensor that reads 0 mph, jumps erratically, or differs from the others is your prime suspect. Next, inspect that corner's sensor, connector, and wiring. If the code points to one wheel, swap the sensor side-to-side only for testing if practical, or follow the factory diagnostic flow before replacing the ABS module.

Can you keep driving?

If only the ABS light is on and the brake pedal feels normal, you can usually drive carefully to a shop. Remember: the ABS will not pulse the brakes in a panic stop, and traction/stability control may be off. Avoid slick roads, hard braking, and towing. If the red brake warning light is also on, the pedal is soft or low, you hear grinding, or the truck pulls when braking, stop driving and get it towed. That points to a base brake problem, not just a wheel speed sensor.

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