So my 2010 Ford escape hybrid gave ABS and Traction control warnings the other day. I checked on my Forscan app and it gave a C0031 error code (front left wheel speed sensor - signal erratic). I drove it around with the output feature running on all four wheels, and the faulty wheel graph was bouncing all over the place. This would suggest that the tone ring is cracked or broken. However, I looked at it up close and is seems to be in good condition. Any suggestions on how to fix this? Is it possible that the sensor is dirty or obstructed?
The first picture clearly shows some kind of contamination on the sensor. Try cleaning it up and see if that helps. If that doesn’t work and the tone ring looks fine, then check the wiring of the sensor. If that’s good too, then you might need to replace the sensor.
Thanks! Is it possible to splice in a new sensor without replacing the whole thing? The wiring’s hard to get at, and I park on the street, so I’d rather not have to take off the wheel.
The sensor should unplug from the harness, so you should be able to replace it without having to take off the wheel.
If rust has built up underneath the sensor, it can push the sensor away from the tone ring, causing a poor signal. You could try removing the sensor and cleaning the mating surface.
I had to replace all four corners on my 2011. It’s a pretty easy job. The rear ones are a little more difficult, but with hand tools, it should take about 15 minutes.