Hi guys,

A customer has been to see me today with a 2001 Range Rover p38 and it shows abs warning light and traction failure on the dash.

I've plugged it in using my nanocom and it says rear left sensor short to another.

Now if I go into the live data it shows that front right, rear right and rear left sensors have 2.35 volts and the front left sensor shows 0 volts.

Also when I do a speed sensor check, the rear left shows that it's not moving and all the others show that they are moving on the live data.

Can anyone please help me with this??

Thanks in advance

We found this at the last summercamp on Morat's car. There was a faulty ABS sensor but Nano showed it to be a different one depending on what menu you used to look at it. There's been a firmware update for the Nano since which may well have cured it. It was Morat, Marty and Sloth who found the problem, one of them should be able to tell you what it was.

It's probable that the ABS ECU has failed. Later (99+) ones with 4 wheel traction control had a physically smaller box and less heat sink capacity thus a higher failure rate.

Well, that's a bit weird.. I've just had to re register as it wouldn't let me log in

Thanks for the replies..

If I check the wiring to the sensors, what voltage should it show?

Also, where is the abs ecu?

Thanks in advance again

This post hadn't appeared when I wrote my reply above. I do remember Nano was reporting 2 different locations for Morat's sensor fault, but can't remember what the reported fault was. If it was the same as Ash's problem, then worth checking sensors before launching into the ECU! At £100+ for used (unless one handy to swap for test) it's a bit expensive to launch straight into it.
ECU is located behind glovebox.

Gilbertd wrote:

We found this at the last summercamp on Morat's car. There was a faulty ABS sensor but Nano showed it to be a different one depending on what menu you used to look at it. There's been a firmware update for the Nano since which may well have cured it. It was Morat, Marty and Sloth who found the problem, one of them should be able to tell you what it was.

Easiest test you can do as a starter is to measure the resistance of the sensors. The faulty one is the one that reads differently to the others and will probably be open circuit. They are only a coil so a break means they don't work.

I'm thinking that I'll swap the ecu from mine to test it, then I can rule it out..

The customer has told me that it's had a new sensor and ring on, so I think I need to look a bit deeper into it

I'm thinking that I'll swap the ecu from mine to test it, then I can rule it out..

The customer has told me that it's had a new sensor and ring on, so I think I need to look a bit deeper into it

Does anyone know what fails on the ecu? And can they be repaired??

But was the right sensor changed? If the Nano is reporting problems with two (a fault on rear left but no voltage from the front left), it may be that the wrong one was replaced. I think that was the problem with Morat's car, one sensor was replaced but the fault was still there until one of the others was changed too.

Further to Gilbertd's suggestion re resistances. if you get as far in as the ECU, it'd be worth checking resistances of sensors AT ECU connector as well as sensors, with sensors both plugged and unplugged. If discrepancies there, chances are it's a sensor/ wiring fault rather than ECU
D1 Page 7 in my version of post '99 ETM in RAVE

Ahh this - the problem was that I had a faulty sensor and the Nanocom reported the fault against the wrong sensor (front left IIRC)
I think the next step was to watch the live values when driving (under 4mph or something small because the ECU switches off comms above that speed) and we saw bad readings from a different sensor (Rear left?)

Don't bother with swapping the ECU just yet. Try recording the live values and compare with the fault report. Marty might have done a quick resistance test as well while I wasn't looking because he was already suspicious of the ABS sensor fault screen on the Nanocom.

The latest (released since summer camp) version of the Nanocom firmware has patch notes that imply this fault is fixed but I don't think anyone has test to confirm that the right sensors read in the right places.

My money is it being the rear left that has failed.

Is there a fault code for which one it thinks is faulty?

Further to this - don't know if it was ever sorted - but I've found a few times that Rear Left sensor short to another sensor is actually a failure in the ECU. I've got one on the bench with this failure in it, and I think I've found the cause. I have components to try and repair it, and if it's successful, then hope to add that to my list of parts that I offer for repair.

If this was the ECU, do you still have the old one? I'm looking for faulty ones to try and repair, so I can eventually offer exchange units like I do with other P38 items...