Hi guys, I hope that this is allowed but I want to look for a bit more information in regards to the ABS/TC warning lights coming on, on the dashboard.

I got under the car yesterday, and following both Richards' and Bolts' advice I gave the passenger side sensor a couple of taps with a light hammer, and the warning lights went out, tested by driving about 1/4 mile. So everything appeared hunky-dory, but I know that you readers have guessed that that is not all.

I went out on a 40 mile, each way, journey and after around 10 miles the warning lights came back on while gently bumbling down a motorway. So I continued on to my destination, parked and switched off ignition.

After three hours I returned and set off again, but after 6 miles this time the warning lights came back on and stayed on until I got home, about 1 1/2 hours - due to heavy traffic.

So could I be looking at, as Bolt suggested, a flaky wheel bearing on the passenger side front wheel. This is where I had a lower reading on the Nanocom, when doing as road test as suggested by Richard. The static readings were all around 2.30, a bit above and a bit below, but when driven slowly three readings varied from the 2.30-ish figure by very little, but the front passenger side sensor gave readings around 1.80.

So tapping the F P Side sensors cleared the fault.

Some research suggests perhaps a faulty wheel bearing, a faulty sensor, or a CV joint going faulty. Do I just have to bite the bullet and change everything ?

Pierre3

Unlikely to be a CV joint but could be either of the other two. The reluctor ring has one tooth fractionally higher than the others so the sensor is tapped in as far as it will go and after one rotation is pushed out so the air gap is correct. It may be that the sensor coil is breaking down every so often (it contains a coil of thousands of turns of extremely fine copper wire) which triggers the fault or it could be a worn wheel bearing that isn't running true so pushing the sensor out too far.

I have had many wheel sensors go AWOL and some of them exhibited initial intermittent failure before finally giving up the ghost permanently. When the fault is present NanoCom will report/assign it accurately as it just takes the fault directly from the Wabco ABS ECU. However, NanoCom reports/assigns three of the four wheel sensor voltages incorrectly as follows:

Nano Front Right = Vehicle Front Right (the only correct reading)
Nano Front Left = Vehicle Rear Left
Nano Rear Right = Vehicle Front Left
Nano Rear Left = Vehicle Rear Right

This has been reported to Blckbox but AFAIK they have never corrected the software so be careful using the volyage readings to identify the failing sensor.

Spot on. I replaced a right hand rear when it was left hand front until I found the nanocom issue. I've put a label on the nano box to remind me.

I wd make sure the ports are clean... get the sensor out, remove the cage, wrap a bit of emery paper round the sensor and give the port a good clean out, then grease it all up. I may be imagining it, but it seems to help the sensor self-gap more effectively, and seems to have worked for me a couple of times ie problem went away, without needing a new sensor.

I got a couple of sensors from RTG on eBay back in Dec 2021. One failed after about 2-3 months, but they replaced it free of charge.

eBay Item

Hi guys, thanks for all your invaluable advice.

In regards to the misreading of the sensors it is possible, I suppose, that this would explain why the rear passenger side wheel goes down over the course of a week ? Although more likely to be the airbag.

I will follow up on all the advice given so freely, but much appreciated, over the next couple of weeks. I need to wait for some good weather, and also to get my walking abilities back !!!

Pierre3.

A corner going down has nothing to do with the ABS, that is, as you suggest, a problem with the air spring.

Hi Richard, what is the effect of the flexible sensor arm not working correctly ?

Pierre3.

That is the height sensor so it reports the height of a corner to the ECU so it knows whether to inflate or deflate the air spring to keep the height or that corner correct. If it is broken or has come adrift, the ECU won't know what height the corner is at and when it puts more air into the spring it won't see the height change so will result in an EAS fault.

Richard, thanks for the explanation. OK, so it looks like I have two problems. one is probably a leaking passenger side rear airbag, and two, one of the ABS sensors is flaky.

I'm a bit disappointed because a guy in Aus is supposed to be sending me 4 Wabco used sensors, in good nick off a P38 that has only had tarmac use in Melbourne or somewhere. I don't think that he is a crook as he has a lot of stuff on the Range Rover P38 facebook forum, a guy named Nick Thomas. But who know, it won't be the first time, and I will look elsewhere.

Pierre3.

Why are you buying stuff from Aus when there are numerous breakers in the UK (and probably a few in ROI too)? Whether it has had only tarmac use or has spent its entire life off road won't make a blind bit of difference to ABS sensors.

Yes, you are probably right. In fact, I contacted James Coleman and ordered some Wabco-D ones from him, this morning, as I am now in some doubt as to the likelihood of the others ever actually turning up.

I was reading that you need a thirty ton press if you want to fit Timken wheel bearings. What happens if you choose SKF bearings instead ? Do you still need such a big press, or can you reasonably expect to be able to do them in the average garage ? And my garage is very average !!!!!

Pierre3.

ABS sensors are ABS sensors, it doesn't matter if they came off a car with Wabco D or an earlier one.

If you want to change the bearings in the hub, yes you do need a big hydraulic press irrespective of what brand you buy. Far easier to just buy the complete hub assembly complete with bearing like this, rear https://www.island-4x4.co.uk/rear-assy-eurospare-ftc3223-p-27885.html and front https://www.island-4x4.co.uk/front-assy-britpart-ftc3243-p-27181.html or https://www.island-4x4.co.uk/front-assy-timken-ftc3226-p-27883.html.

Gilbertd wrote:

ABS sensors are ABS sensors, it doesn't matter if they came off a car with Wabco D or an earlier one.

If you want to change the bearings in the hub, yes you do need a big hydraulic press irrespective of what brand you buy. Far easier to just buy the complete hub assembly complete with bearing like this, rear https://www.island-4x4.co.uk/rear-assy-eurospare-ftc3223-p-27885.html and front https://www.island-4x4.co.uk/front-assy-britpart-ftc3243-p-27181.html or https://www.island-4x4.co.uk/front-assy-timken-ftc3226-p-27883.html.

I wonder why the front hub assembly is £100 while the rear hub assembly is £400. The rear hub assembly is available at Rimmers for £288 https://rimmerbros.com/Item--i-FTC3223P while a genuine JLR part costs £828.

Other way round. It is the front that is expensive probably because there is more to it.

Thanks for all the invaluable information, guys. I just need a bit of good weather to get the wheels off the ground, to check the bearings.

Is there any reason why I can't tighten the bearing ? If there isn't much movement in the bearing can I not tweak it up to take out any looseness in the bearing ? It would just save all the work replacing the hub, or getting new bearings fitted.

I wonder what type of bearings are fitted to the Britpart hub, as I notice that the Island 4x4 hub is listed with the Timken name so I am guessing that Timken bearings are fitted to this hub.

Pierre3.

It is a dual ball bearing so there isn't any adjustment like there would be with a pair of taper roller bearings.

Thanks Richard, that's another bit ruled out. I still have to find the opportunity to check these bearings, as the weather has not been the best.

Pierre3.

So I finally got a bit of luck with the weather, nice and warm, and sunny this morning. I jacked up the car and grabbed the wheel top and bottom and gave it a good pull and shake in both directions. It's absolutely solid, there is no give in the bearing at all, from what I can see and feel.

I just need to wait for some Wabco sensors from a breaker, to arrive and I will stick one in the front left hand [passenger] side hub and hope that the ABS/TC message clears off, permanently. I am fairly sure that the current sensor is a spurious one, as I had one replaced around 18 months ago - I just can't remember which one !!!

I also spent an hour and a half replacing the sidelight bulb on the drivers side front, in behind the battery. Being as I have the largest 950 a/h Yuasa extra heavy duty battery fitted there is very little room to get my hand between the battery and the headlight, and then under the headlight plug to twist/undo the sidelight holder. It is just easier to remove the battery and then twist the holder. I had to do a small bit of cleaning to the bulb holder and then the actual plug connected to the wires. I used electrical contact cleaner and gave both plugs a good soaking. Then a scrub with a toothbrush, and finally a blast of brake disc cleaner. Now the bits are all squeaky clean, and the fresh bulb is perfectly happy, shining out its' little shiny message !! Just wish that it is a bit easier and quicker.

Pierre3.