Hi Guys. Just popped in from the X300 forum as I have offered to help out a friend with a 2002 S Type 3.0.

The car has had ABS/DSC codes read by a garage who list them from their diagnostics as

C1144 - Right Rear Wheel Sensor Cog missing
C1235 - Right Rear Wheel Sensor Signal implausible

That sounds logical, but in doing some research. The C1235 is listed in the 2002 S Type DTC document as Right hand Wheel Sensor. The C1144 code does not appear in that document.





However, the 2002.5 (which this car is) DTC Document lists C1235 as Left hand Wheel Sensor.





So - did Jaguar really change C1235 from Right to Left with a model year change, or is this an error in one of the documents? Can anyone provide any clarity? I'm trying to establish whether we have an issue on both rear wheels or just the Right hand.

Thanks in advance. I may be back with more questions when I actually get to have a look at the car next week.

who knows? buy a new sensor and replace one side. if it fixes it you have your answer

If you can get the vehicle on a lift..Check the tone rings on both rear axles for cracks. Sometimes they even expand enough to contact the ABS sensor.

Thanks for your replies. The car is coming to me on Tues next week and I will do some diagnostic testing and report back what I find.

Just to conclude this one.

I did a code read myself and only got codes for the Rear Right wheel (and a whole bunch of other stuff for gearbox, engine etc that was related to vehicle speed) and then did some live data observations of the rear wheel sensors. The Left was fine and the right was spikey.

So I checked out the reluctor ring as suggested by @Catfan01 and the sensor. I could see a lot of corrosion under the reluctor ring which had caused it to expand in a couple of places. So much so that it was actually interfering with the sensor. You can see in this picture a small shiny area that has been polished by touching the sensor.






I replaced the RH driveshaft including the ring (the price difference for the CV joint or the whole driveshaft was small) and the sensor (although I think the sensor may have been OK) cleared the codes and all is good.

I did mention to the owner that the rear left was looking very similar and that I’d probably see him soon to do that side also!