Volvo S90 ABS Light Stuck On? Your Wheel Speed Sensor Might Be to Blame

So, Your Volvo S90's ABS Light Is On for Good

I see this all the time. The ABS light in your Volvo S90 II comes on and just stays there. That means the ABS control module has found a problem and shut down the anti-lock braking system. The usual suspect is a wheel speed sensor, but it could also be a chewed-up reluctor ring, a broken wire, or a tired ABS module. The good news: your normal brakes still work, so you're not stranded—but you do lose ABS, traction control, and stability control.

Check These Parts First (In This Order)

• Wheel speed sensors: There's one at each wheel. They get coated in brake dust, crack, or fail internally. A scan tool will point to the guilty wheel. Pull the sensor and check for metal shavings or a damaged tip.
• Wiring and connectors: The harness near the wheel well often rubs or corrodes. Wiggle the connector and look for green crust or broken wires.
• Reluctor ring (tone ring): This magnetic ring lives on the CV joint or wheel bearing. Cracks or missing teeth will confuse the sensor. Give it a close look when the wheel is off.
• ABS module and fuses: If all sensors and wiring check out, the ABS module itself might be the problem. Check the fuses first, then consider a rebuild or replacement.

Can You Keep Driving Your S90?

Yes, but treat it like a warning, not a suggestion. You still have regular brakes, but without ABS you can lock the wheels in a panic stop. Traction control and stability control are also offline. So take it easy: no hard braking, no slippery roads, no aggressive cornering. Get it diagnosed soon—a simple sensor swap is cheap, but ignoring it could hide a bigger brake issue. If the red brake light is also on or the pedal feels mushy, park it and call a tow.

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