Got and odd problem that I'm a bit lost on.
When I bought my VDP in June, it had the ABS light on. I got a really good deal on it and I had researched a little beforehand what causes the light, so it wasn't a deal breaker. I brought it home and cleaned all 4 speed sensors. That shut off the ABS light and error message.

Since after I cleaned this (probably was happening when I got the car too), the ABS system seems to kick in just when I am slowing down, nearly to a stop. The brake pedal pulsates a little and I can hear the pump running. It happens at very low speed (5 mph or less) and I think I may have heard the pump running occasionally driving without my foot even touching the brake, though I am far from sure about the noise here.

I have no indicator lights, nor do I have any messages about anything unusual or failures in the message center. My OBDII is showing no codes.
I'm wondering if the ABS module is bad; but before I start swapping parts, am I even looking at the right part?

Thanks for any ideas . . . .

 

Before concluding that the module is the problem you may want to check each wheel to make sure that the one of the brakes is not grabbing. If the car pulls to one side when braking this would be an indication that one of the front brakes is grabbing. You can also raise the front of the car and manually rotate each wheel. They should require the same effort to spin each wheel. The rears are not as easy to check because of the drag from the differential.

You can also pull the fuse for the ABS and see if the braking feels different with the unit disabled.

 

Welcome to the club!

Mine does the same thing (98VDP). The pulsating brake pedal I wrote off to the worn/warpped rotors, and I will be doing the brake job soon. The "noise" (more like a short "buzz") comes on sporadically, and I haven't been able to pinpoint where it's coming from. No codes, no warning lights, nada!
This buzz comes on sometimes when the car is cold, and I never hear it again during the day (foot is nowhere near the brake when I hear it!).

 

pod184, if you are using a generic code reader it is unlikely that you will see ABS codes, as they are Jaguar specific. You would need Autoenginuity with the Jag add on or a shop with IDS capa bility.

 

Are ALL 4 tyres the same size???
The rear tyres can be slightly larger and not trigger the ABS.

You can watch all 4 wheel speeds with a datalogger interrogating the ABS module.
They must be within a certain tolerance of wheelspeed to keep from triggering the ABS.

What DTCs (if any) are logged in the module.

We can all guess at the fault.

bob gauff

 

Lot of good ideas here.
I think I have a questionable front left brake caliper, its on order and hopefully will be here this week (no dealer within 200 miles, so pretty much everything needs to be ordered). I'm not exactly sure how something like this would happen, but there is a possibility that either the caliper or the caliper bracket is a little bent. The wear pattern on the rotor is odd too, so that will also be replaced, along with front pads. I didn't think a caliper would affect the ABS, but it might be somehow interacting.

I've noticed the previous owner has at least 2 different brands of tires on the car, I didn't look at the size, though, so I'll check that too. I'm looking to replace the 16" wheels with 18" in the not too distant future, so that'll probably straighten out the problem as well.

Thanks for the input!

 

So this is an old post, but I figured I'd follow up in case someone stumbles on this in the future.
I checked the tire size, they are all the same size. Speed sensor ohm'd out OK, I had installed a new brake caliper (with bracket) as the brake pads seemed to be wearing oddly.

The strange/uneven rotor wear continued even after replacing the caliper. The other really odd thing with the rotor was that when I put the new caliper bracket on, I had to add some spacers to the bracket in order for it not to touch the brake rotor.
I contacted the previous owner, he claims that he didn't know of any previous damage to the front left wheel.

I located a salvage knuckle from a '98 XJR, which arrived yesterday. I put it on last evening and took a test drive.

NO MORE ABS PULSING and the brake pad is now wearing normally!
Something was entirely wrong with the old knuckle, I'm guessing something must have impacted it and done bad things to cause both problems even though it didn't look bad.

I did notice some play in both ball joints, now on order so that will probably be the next big project. . . . .