Hi All, is it possible to test the wheel speed sensors for an ohmic value to prove they are good/bad?

 

You have to remember it is a hall effects sensor so depending on where each ring resides with respect to the sensor you’ll get lots of different readings. It may be possible. Jack up a couple of wheels attach your ohmmeter, spin the wheel slowly, record your value. Since it is a Hall effects sensor it produces a current as the cog passes the sensor coil so, slowly turn Turn the wheel and watch for changes and see if any of the readings look different from the rest

 

It is not really practical to test the wheel sensors using a meter as the results are often inconclusive.
By far the best way is to use the Jaguar software to identify the location of the faulty sensor and then replace it.
I have got to do this at the weekend myself as I got the classic ABS, DSC, speed control fault when driving on Monday.

However, a visual inspection may help to make sure the inductor ring has not swollen with rust, so it is rubbing on the sensor.
Mellow

 

you are correct! After I made my post I did a little research on my own car as I was having a can bus error speed signal faults being thrown periodically and I found out that the sensors are typically small current producers that aren’t really changing the resistance but instead send current back to the modules. so potentially you could read the signals with a meter if you had it set on the diode test mode but I haven’t checked myself. I did use SDD to look at each wheel sensor signal As I checked each Wheel on it by hand, I made sure that I had signals and that they did not drop out

 

Hey guys,

Are we on the right path here? The thread title mentioned limp mode. But then the actual question asked about testing wheel speed sensors. Aren't we off in the weeds? A bad wheel speed sensor can cause certain faults (such as antiskid, cruise control) but can it cause the engine to go into limp mode?

 

It can also cause transmission faults, which in turn can trigger "reduced performance" mode, or so I am told... Perhaps one of our other Tech Mavens can weigh in on the subject?

 

I have just plugged in the Mongoose interface to my 05 model year STR, my 30 Amp 13.8v (adjustable voltage) stabilised power supply onto the battery, the Window XP laptop running Jaguar SDD130 with a date reset code to the same date in 2012 each time it starts (with no internet) and it identified the failed right rear ABS speed sensor.
I now have one on order and will fit it next weekend.
I sort of guessed this was the fault as I changed the left hand rear speed sensor about 18 months ago, but SDD software confirmed the fault so I could order the right part, and I know what one to change.

As I said the Jaguar SDD130 software is the best way to identify the faulty ABS speed sensor, and just about any other faulty sensor on the s-type as well.

Mellow