Disco 2 Wheel sensor....

[Spong]

The three amigos have been visiting occasionally for a while as I've not got around to the SVS mod yet, but the last couple of times they brought a friend along in the guise of the brake warning light - Nanocom says front right wheel sensor.

Any recommendations for the sensor? I would normally go for a good brand, in this case Wabco, but are the others just as good in this instance?

Is it usually the sensor, or does often turn out to be the loom or the connection at the other end?

 

[Stanleysteamer]

It often turns out to be the hub, and its attached sensor of course. The official LR line is to replace the hub with its sensor already fitted.

 

[neilly]

Have you jacked it up and spun the wheel to see what state the bearing is in?
There is normally a connector on the inside of the wing, you could try giving it a clean.
I have used the £55 hubs from aapoldham on the bay for 3 hubs, worked fine with no issues . Longest one has been on now for 25K miles.

Cheers

 

[Spong]

It often turns out to be the hub

It did cross my mind, as a garage fitted a new lower ball joint on that side for the MoT in February and had to take to hub off to do it apparently - I later found that they had 'bruised' the hub flange, so that the disc didn't sit flat anymore. I've since corrected that, and this problem is only showing up now, so may just be coincidence.
What is it about the hub part that would cause the sensor warning?

 

[Stanleysteamer]

+1 ^^^
What others say is that the flipping sensor is so sensitive that even if you can't feel any play in the bearing, the sensor feels what little play there is and chucks its toys out of the pram.
This is what LR feels hence their recommendation. Obviously they are not us, they are instructing their service technicians in what to do to get the least come back.
You could also try measuring the resistance of the sensor and comparing it with all the others, but even then, even if they are all within a few microohms of one another, the blinking light can still come on.
Watch it with Nanocom, I think I have heard it said that they can get the right result but for the wrong wheel. I know a certain garage did that to me and I ended up replacing two hubs to get the correct one. On the same axle. Try disconnecting the sensor and see if it comes back with the same code. If it doesn't, try reconnecting it and disconnecting the other sensor on the same axle. You may be in for a surprise!

 

[Spong]

Have you jacked it up and spun the wheel to see what state the bearing is in?
There is normally a connector on the inside of the wing, you could try giving it a clean.
I have used the £55 hubs from aapoldham on the bay for 3 hubs, worked fine with no issues . Longest one has been on now for 25K miles.

Cheers

I put new discs and pads on a few weeks back and didn't notice anything odd - other than the damage to the flange. I'll have a look at the wiring and check the hub again while I'm there.

If I don't see/feel anything wrong with the hub or wiring, I suppose buying a cheap bluebag one would at least prove it either way.

BTW, I notice a choice of long cable versions and short cable - what's that about?

 

[neilly]

What reading sdo you get from the nanocom?

It should show the readouts from each of the hub sensors.

Cheers

 

[Stanleysteamer]

Apparently, when the hub has play the reluctor ring-to-sensor gap varies and this gives the wrong reading to the electrickery which puts the lights on.
I watch myself like mad now when giving electrical advice as @sierrafery quite rightly jumps all over me when I get it wrong. But I seriously have been here and got the T-shirt. I may use the wrong technical terminology but the end result is the same.

 

[Stanleysteamer]

I put new discs and pads on a few weeks back and didn't notice anything odd - other than the damage to the flange. I'll have a look at the wiring and check the hub again while I'm there.

If I don't see/feel anything wrong with the hub or wiring, I suppose buying a cheap bluebag one would at least prove it either way.

BTW, I notice a choice of long cable versions and short cable - what's that about?

Long cable are front hubs, short are rear, and if you try to fit a front hub on a rear axle, you have to faff about a bit more and you'll need another O ring. Ask me how I know! Thanks garage, GRRRR!

 

[Spong]

What reading sdo you get from the nanocom?

It should show the readouts from each of the hub sensors.

Cheers

I think they all read around 1.0something, but that was stationary, presumably I need to be rolling to see if the signal is correct.

 

[neilly]

I think they all read around 1.0something, but that was stationary, presumably I need to be rolling to see if the signal is correct.

Does help, LOL, Give it a run and check the signal, see if one is giving a dodgy read. I have seen a couple of knackered bearings , bad enough they were not just rough but you could feel the slop in the wheel and yet the 3 amigoes did not turn up to say hello.

But be careful ,changing a sensor in a hub can be a right nightmare, I had one that would not come out , the bolt was completely siezed.

Cheers

 

[Spong]

Long cable are front hubs, short are rear,

Think Island 4x4 must be confused then, as they are showing front sensors available as both short and long....

 

[Spong]

Does help, LOL

Thought it might! I'll hook it up for the run to work tomorrow and see what it says.

 

[Stanleysteamer]

Think Island 4x4 must be confused then, as they are showing front sensors available as both short and long....

Without crawling around my truck in the dark I cannot be sure but there may be a side-to-side difference. But the rear sensor cables connect to the loom under the wheel arch and the front ones connect under the bonnet, so there is a definite difference between front and back.
To cut a long story short, I found myself fitting a front hub to a rear wheel. The hub to axle bolts were a different length so I had to reuse the originals. There was an O ring missing which they had to send me separately, the whole cock up was their mistake, and I had to mess around with the fixing and sealing grommet-type things as they are very different front to back.
That said, a front hub can be made to fit a rear axle but you do have to "lose" the extra cable length.
But this isn't your problem.
Did you try disconnecting the allegedly faulty sensor to see if Nanocom got the side right?

 

[Spong]

No, all I've done so far is to plug the Nanocom in while stationary and saw the reported sensor fault. I'll do a check on the move tomorrow and report back...thanks to you and @neilly so your help so far.

 

[Stanleysteamer]

No probs, glad to help.
But you can do the disconnect check while stationary and I'd strongly advise it as Nano's do have the problem of not knowing left from right. It take 5 minutes to confirm it hasn't got its knickers in a twist. Wish I'd known about it before fitting a new hub to the wrong side!

 

[sierrafery]

No, all I've done so far is to plug the Nanocom in while stationary and saw the reported sensor fault. I'll do a check on the move tomorrow and report back...thanks to you and @neilly so your help so far.

Hi, unfortunately you can't check too much on the move as nanocom will cut off when the vehicle exceeds 5mph or so... you have to whatch live stationary inputs which should all be between 2 - 2.4V , if one is out the sensor is the problem if all are within limits you'll most probably need a hub

Think Island 4x4 must be confused then, as they are showing front sensors available as both short and long....

there are short an long sensors for both front and rear, you have to visually check what you have on the vehicle and order that cos it's spec, VIN and year dependant as there are various combinations.

 

[NPG]

Think Island 4x4 must be confused then, as they are showing front sensors available as both short and long....

The long ones are probably for vehicles with raised suspension.

 

[NPG]

If you plan to measure sensor resistance at rest, you should read somewhere between 950Ω and 1.1kΩ. Sensor voltage at rest should be in the region of 2V and 2.4V.
If you buy a new hub, make sure it has the 60 tooth reluctor ring. I'm not saying those with 55 teeth wouldn't work but avoiding grey areas is always a good thing.
I personally have good experience with BP wheel hubs (80K km +) as long as the stake nut is torqued to spec (490Nm).

 

[sierrafery]

The long ones are probably for vehicles with raised suspension.

No they are not, those with long leads dont have a connector, they are hardwired into the ECU plug, mine had hardwired front sensors from factory but i cut the wires and installed connectors as to accept new hubs with theyr's sensor as it is