I have recently purchased a low mileage 2006 Scion XB and have had to have a faulty front ABS senor replaced at a local repair shop. The mechanic used a
“genuine Toyota” replacement sensor. After a couple of miles my ABS light along with the TRAC and VSC lights came on. He reset the computer and they came on almost immediately. His computer read faulty ABS sensor, he said that he checked the new sensor and it worked. He sent me to Toyota, who also diagnosed it as faulty sensor and when they checked the sensor it was fine. They said the problem was rust, cleaned the sensor and hub and everything was fine for about 50 miles, then the lights came on again. The service manager said that if the problem came back that they would have to replace the front hub. Can I again clean the sensor and hub myself? I have a bead blaster would that likely clean it enough? Would coating the cleaned metal with something like a really light oil (like WD 40) help to stop the rusting? And lastly, if I am successful in cleaning it all does the computer need to be reset or will it reset itself? I have some skills, have done brakes, replaced engines and stuff like that. Thank you all.
You could try cleaning it, but wd40 will evaporate. I would use Brake grease. It will not be affected by heat or moisture.
The wheel speed sensor is replaceable without replacing the wheel bearing. The problem might be with the wheel bearing itself.
The wheel bearing also includes the tone ring for the wheel speed sensor which the sensor gets its signal from.
If the wheel bearing is at all worn out, it’ll cause the tone ring for the wheel speed sensor to become misaligned with the sensor causing the ABS light to come on indicating a sensor code.
And if the ABS light comes on, the TRAC and VSC lights will come on automatically because they’re saying we’re not going to function as long as there’s a problem with the ABS.
Tester
Why do they want to replace the hub? The trigger ring is built onto the cv axle. Odds are it has a chipped tooth, this can be easily verifyed by watching the waveform for the speed sensor on a scope.
Thank you Guys. “My service adviser” at the Toyota dealer gave me his e-mail address. I have e-mailed him with only an automated response. I took the sensor out today and indeed it had a few pieces of rust on it. The teeth looked great, like new, no chips that I could see, the axle had a bit of rust, not a lot. I cleaned the axle, put it together and the lights are still on. My local mechanic said that they should not need to be reset, that they will reset themselves once the problem is solved. Tester, the wheel bearing seems alright, I cannot find any movement in it. The car has only 23k on it. Again, thanks. Although I do not have a lot of confidence in my service advisor at this time I will likely go and see them again, see if they can figure it out.
Maybe it’s the wiring. Have you checked the connectors on both ends? I had a similar problem on a 2003 Olds and it was corroded/dirty connectors at the front wheels. Certainly my van was a lot older than your car when this started (12 yrs) but it might be what you need.
There’s two parts involved w/the wheel speed sensing function as Tester above pointed out. One part is the electronic sensor, which is fixed in place. The other part, the sensor activator, goes round and round with the wheel. If the other part (the one associated with the hub/wheel bearing/CV joint, whatever it is on this car), trying to solve the problem by replacing or cleaning the fixed electronic sensor will never solve the problem.