Defender ABS Light Stays On? Check the Wheel Speed Sensor First

Don’t panic — but don’t ignore that amber ABS light

On a 2020 Land Rover Defender, a continuously lit ABS warning light usually means the ABS control module has logged a fault and disabled the system until it’s repaired. The most common culprit is a wheel speed sensor or its wiring, but it can also be a dirty or cracked tone ring, wheel-bearing play, low battery voltage, or an ABS module/software issue. Because ABS and stability control may be unavailable, treat it as a “get it diagnosed soon” warning rather than a cosmetic annoyance.

Start with a proper scan using Land Rover-compatible diagnostics, then watch live wheel-speed data on all four wheels while driving slowly. A sensor dropping out, reading erratically, or showing a different speed to the others is a strong clue. Next, inspect each sensor’s connector and harness for corrosion, chafing, or moisture, and check the tone ring/reluctor for dirt, cracks, or missing teeth. Also check wheel-bearing play and battery/charging voltage before condemning the ABS module.

• Check first: fault codes and live wheel-speed values.
• Inspect: sensor connectors, wiring, tone rings, and wheel bearings.
• Don’t guess: avoid replacing sensors or modules without confirming the signal fault.

Is it safe to drive? If you only have a steady amber ABS light and the brakes feel normal, a short, gentle trip to a workshop is usually acceptable — but remember ABS may not intervene in an emergency, and hill-descent/stability functions can be affected. Avoid wet, loose, or slippery roads and don’t tow if braking feels odd. If a red brake warning light appears, the pedal feels strange, or the light flashes, stop and get professional help.

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