More ABS woes - Defender TD5

Hi all
There are hundreds of ABS posts around but I can't find any that tie up with what I've got.

My ABS and TC lights came on one day a few months ago and haven't been off since (while ignition is on anyway). I got hold of a nanocom and interogated the WABCO ECU which was registering an intermittent shuttle valve switch failure, but when cleared, there was no improvement in the situation. The fault code does return after driving a bit but I don't think this is my problem.

When viewing the ECU inputs, all seems normal as far as I can tell. There is 2.2V registering at each sensor and each wheel is showing a nominal 1.7kmph at standstill, except for the rear left which is showing 426kmph. I have replaced the rear sensor harness assembly and there was no change. If I plug the old harness in, with the sensors lying on the ground, there is no change. I swap the plugs and get the same readings again. If I unplug the left rear sensor, the speed seems to float around 5kmph and the system does not register a fault, whereas if the other side is unplugged, that wheel drops to zero and the open circuit is registered as a sensor failure. All plugs are sound, clean and dry and I have good continuity resistance readings from the header on the ECU.

My conclusion is that the sensor conditioning circuit on the left rear channel has gone wrong inside the box. Is there anything else I can try to confirm the diagnosis? Has anyone had this kind of fault before and if so, what did you do? Can the ECU be repaired or is it a case of getting my wallet out and replacing it?

Any advise would be much appreciated, especially if it saves me a quid or two.

Cheers

Andy

ye could try postin' this in the relevant section. Ye never know, ye might get a response.

There have been several ABS ecu's on ebay for a couple of pounds recently. I would try buying one of them and see if that clears it. There is a company on there who are selling seconhand ones at £60 if you are in a hurry for it but I would wait til a cheapy one pops up.

Thanks for the tip Ratty. I'll keep a lookout for one. I have a few weeks before MOT time. If anybody spots a cheap one anywhere (and you don't want it youself), let us know?
Cheers

hi mate having exactly the same bother with my 90,exactly the same diagnosis with the nanocom,my mate who works for land rover is currently working to sort it so i'll let you know how it goes

Hi wee jock. thanks. I'd be very interested in what your mate finds out.
Cheers

Don't you just love it when a thread dies in mid story. This is exactly what I have on mine and the answer is ... I still don't know!

No fault lights on mine though and ABS and TC seem to be working find so I think I'll just keep an eye on things. I guess it could be one of those Nanocom things (like having two front left ABS output voltages but no rear left - presumably the second is the rear left).