Hello. I have an 04 XJ8 that has been throwing the occasional ABS Fault / DSC Not Available. By occasional, I mean it comes up about 1/50 times and immediately goes away if I turn the car on / off.

I scanned the car with my new Launch CRP123E. It came up with Code C1144 under the ABS module, which translates to "Rear right wheel speed sensor tone ring tooth missing fault".

My question is whether this fault is resolved by replacement of the wheel speed sensor, which is easy, or does it indicate an issue with the "teeth" part of the wheel that the sensor "senses"? I'm not averse to replacing the wheel sensor, and I've read about how one should just clean them as routine maintenance, but it doesn't make a sense to me why the fault would be so intermittent. If it's a problem with the metal "teeth", then it should happen all the time. If it's a problem with the sensor being dirty, and I don't clean it, why does it go away the next time?

Anyway, thanks in advance for the help.

 

Rust can be loose / flake off the ring so you should expect intermittent.

It may clean up but may need replacing.

 

Don't worry about the fault appearing to be intermittent.

You have diagnosed the source of the fault.

I suggest you remove sensor and clean it and examine

the reluctor ring and clean it.

It could be just dirt or rust in the slots of the ring.