Afternoon all

Changed my rear ABS sensor yesterday so thought I'd share with you my experience. Firstly the old style sensors are mega bucks so don't do what I did on one side of my car when I did the rear wheel bearings and snap it off thinking don't worry that'll cost me £15 on Autodoc. The main UK suppliers of Jaguar spares don't even have these in stock very often and I managed to get one from a specialist dismantler for about £100. Needless to say a few weeks later when I did the other wheel bearing I was much more careful.

Anyway, had the "ANTI-LCOK" light on now about 6 months with the "new" sensor in the boot and with MOT due this week thought I better fit it. Loads of guides on replacing the sensor but very little information about where the connector is: I asked the question a few times on here with no success. To get to the connector remove the fusebox covers on the "heel board" i.e. the vertical bit in front of the seat - one Phillips screw per cover. Then you will see two more screws which hold the seat bench down. Push the seat buckles through the holes in the seat bench and remove. Collect the coinage that will be found there: in my case £1.74 and 2 euros. Pull back the foam covering and you will see the connector. Laying on your side you can push the connector up through the hole in the floor with your left hand and pull it through inside the car with your right hand. Plug it in.

When I started my car the light went off but when i drove more than 10m it came back on. This repeated itself 4-5 times before I resigned myself to have bought a broken sensor 6 months ago with no chance of a refund. Hours of searching last night and came up with nothing at all in the UK, NL - one in Germany for an XJS that they said would fit but didn't want to risk it Then set about learning how to check the sensor ohm and v output which I was going to check when I get home today. BUT this morning, started the car and drove off - the light stayed off and all is well, I felt the ABS working under heavy braking so thank goodness I didn't find one for sale last night and waste another £100+!!!

Hope useful.

Sam,

 

The rear seat cushion has a tendency to force the connection apart. My warning light came on seemingly erratically until I spotted that it was always when I had a passenger in the nearside rear seat!

 

My abs/trac light has been coming on erratically as well.
I recently checked the sensors and all four measured around 800ohm at the sensor connectors, but the rear right one was at 1300ohm when measuring it through the ABS multi-plug in the engine bay.
Might be a damaged wire from the rear seat to the engine compartment that causes the high resistance and therefore the error?
Tried cleaning the plug with some contact cleaner but it didnt make any difference.

I still need to check the voltage while rotating the wheels, but if that measures ok, i guess i'll try pulling a new wire from the back seat to the abs module and to see if the lowered resistance clears it.

 

My issue was that part of the metal frame which seems to help to hold the seat cushion in was directly above the connector connecting the rear left hand ABS sensor to the main loom. The downward pressure of someone sitting in the seat was just enough to cause the connector to ease apart and break contact momentarily. Once the warning light is on, it stays on for the rest of the trip, and ABS and traction are inoperative, although the speedo resumes.

 

Sorry I didn't see your previous asks about the connector. I could've filled you in. Last year, about this time, I removed the entire IRS assembly from a 1996 LWB VDP and a matching IRS from a 1997 base spec XJ6 but with knackered and very noisy diff, and swapped 'em. (The 96 is now affectionately known as "T-Bone" owing to a rather unfortunate incident my youngest lad put it through while away at college...but anyway, has become my parts car.

Found the sensors were different between the 97 and the 96. 96 are identical to the ones on my 95 VDP, as well. The casting on the rear hub assembly was changed for the 97 model - not certain if it was at exact model changeover, but likely there is a VIN switchover point. Anyhow..the axle swap required a sensor swap, as well - because the configuration of the newer sensors is such that they will fit into the hole and you can secure them with the same bolt...but! the sensor connector is butt-up against the dust shield, pointed outboard, leaving you no room to connect the wiring harness. (Yes, the 97 sensors have a disconnect at the sensor itself, so if a replacement is req'd, you don't have to buy the wire loom with it)

I noted in the Jag parts book that no corresponding change was made to the ABS module, so reckoned the old sensors should work on the newer car. Initially, I got the ABS light and codes for both rear wheel sensors and became heavy-hearted and crestfallen. However, after clearing them via WDS a couple of times and making a few short road trips, all was well.

I meant to do a "How-to" on the IRS Swap and mention the little ABS Sensor landmine for those who may be about to head over to their local breaker to get an ABS Sensor or two...but got distracted by a shiny object and never got round to it.

 

Early 97s like mine use the old type sensor, changeover had to be made sometime in or after 10/96, probably to gear up for 308 production. I found two holes on mine for either config.