ABS Light Stays On in a Geometry A? Start With the Wheel Speed Sensors

What's likely going on

The ABS warning lamp on your Geometry A is designed to stay on when the system detects a fault. The most common culprit is a wheel speed sensor — the small magnetic pickup that reads how fast each wheel is turning. These sensors live in a harsh environment, close to the brake rotor and road splash. A sensor can become dirty, its wiring can chafe or corrode, or the sensor gap to the toothed reluctor ring can open up. In many cases, the sensor itself is a separate, replaceable part, and you don't need to replace the whole hub or bearing assembly. But on some variants the sensor is integrated, so it's worth confirming the exact layout for your model year before buying parts.

Where to start checking

First, scan the ABS module for trouble codes. That will usually tell you which corner is affected, and whether the fault is electrical (like an open circuit) or a signal problem (like a missing or erratic pulse). Next, visually inspect the wiring and connector at that wheel. Look for cuts, frayed insulation, corrosion in the plug, or loose mounting. Then check the sensor tip for metal debris and verify its air gap against the reluctor ring — spec is usually around 0.3–1.0 mm, but check your workshop manual. If all that looks good, a multimeter can measure the sensor's resistance and output voltage while spinning the wheel. Dirty or slightly damaged sensors are often cheap to replace on their own. But if the fault is in the wiring harness or the reluctor ring, fixing that specific part is usually more straightforward than swapping an entire knuckle or hub assembly.

Can you keep driving?

You usually can keep driving, but with an important caveat: the ABS, electronic brake-force distribution, and often traction or stability control will be disabled. The base hydraulic brakes will still work normally, so in dry conditions on a clear road you'll likely notice little difference. However, in the wet, on gravel, or in an emergency stop, the wheels can lock up more easily, increasing stopping distance and the risk of a skid. If you must drive, leave extra following distance and drive gently. But don't delay the diagnosis — a wheel speed sensor also feeds the car's stability control, and on the Geometry A it can affect other driver-assist systems. Get the fault codes read and have a trusted mechanic or our diagnostic service narrow it down before replacing anything.

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