I could do with some advice/assistance, please. My garage guy fitted a new ABS sensor this afternoon, a Britpart sensor, and everything was OK. I went out to the shops this evening and te ABS/Traction fault message has appeared back on the dashboard, with the warning lights coming on. Unfortunately, I have an MOT tomorrow morning and I am wondering whether there is any way off getting rid of the message ?

I am wondering whether there is any way that I can cancel or delete the ABS messages using a Nanocom ? If I cut the sensor cable can I just short it out ? Can anyone suggest an alternative means to clear the message before the test in the morning ?

I remember Richard [GilbertD] writing up which Wabco option, using Nanocom, I need to use. I have a 2001 2.5 DHSE automatic, and I remember seeing two options after plugging my Nanocom in for the first time - was it Wabco C and Wabco D ? And which one do I need ?

I am not at all familiar with Nanocom so bear with me please !!!!!

Pierre3.

You'd be able to clear the message with Nanocom, but the source of the error might well cause it to come back again if its not fixed. I'd think a later vehicle like yours would be Wabco D but may be wrong there, it won't do any harm going into the wrong one, it just won't work (probabbly won't talk to it at all I'd guess).

It may have come on for a different reason, so the first thing you want to do is connect and read the faults to see what its complaining about, it may be something unrelated, or may be a loose connection if they haven't pushed it in fully. Or maybe a faulty sensor if its living up to the usual Britpart reputation.

Cutting the sensor cable is not going to help, it will only give either an open circuit or short circuit fault depending what you do after cutting it.

If your committed to the MOT/NCT test tomorrow I'd try clearing it and hope for the best, you might get through it then be able to sort it afterwards if the light stays off during the test (clearing just before you get to the test centre might just be enough to get through depending what the fault is).

BrianH, very many thanks for your suggestions. I wasn't sure about cutting the cable because I have read that the sensor is what is called a Hall-effect sensor, and I had some experience with these sensors in revolving doors that I used to install. As you say, cutting the cable and shorting the two inner cables may not solve the issue. I was hoping to hear that joining the sensor wires together would close the circuit so that the ECU would see a permanently closed circuit and report it as normal, thereby switching off the warning lamps.

I will just have to get the jack out, first thing and see what I can do with it. I have the feeling that clearing the message with Nanocom will not help me much - I think that the fault will just come back.

Pierre3

The ECU checks the resistance so if the message comes up as soon as the ignition is turned on, then it is seeing something other than what it expects to see. Then it looks for the same rotation on each wheel as soon as you start to move and if there is a difference, even a very slight one, it brings on the warning lights too. If a new sensor has been fitted it's a toss up between two things. Either the Britpart sensor is a different resistance to the others so it is failing the self test or it hasn't been pushed fully home. If the former, you aren't going to be able to fix it without replacing the sensor, if the latter, tap it with a mallet and make sure it is pushed fully home. One of the humps on the reluctor ring it taller than the others which pushes it out so the air gap is correct.

If it was a petrol car, up to 98 model would be Wabco C, 99 and later would be Wabco D. I would assume the diesel changed at the same time but can't swear to it. Wabco D has 4 wheel traction control if that gives any clues.

Personally i'd focus on the re- seating option first. You dont need a jack, just put it on full lock...check they cleaned the housing, and gave it a new cage, with a bit of copper grease. And dont hit it back in with a hammer: o)

Excellent stuff, you guys. Thanks very much for all the advice and information.

I will have a look at the way the sensor has been fitted. Hopefully, hopefully, it is a seating issue. What do I use to tap the sensor further into the wheel housing ? Do I use a hammer and a piece of wood or can I use a copper-headed hammer ?

Pierre3.

Copper headed mallet will be OK if you are gentle, you just need to tap it not belt hell out of it. I even tapped one into place with the end of a wheelbrace in the car park of our hotel at one of the P38 summer camps. The owner of the car was complaining that the warning lights were on and it was all we had to hand at the time, toolboxes having been left at Marty's workshop.

Thanks Richard. I actually have a plastic head hammer somewhere in my garage. I think I will go out now and look for it. Thanks again.

Pierre3.




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Edited- 16th March 2022.

The car passed the annual road test. Finally. The first time it was due, last October, the drivers door latch packed up the evening before the test, and the car had to be lifted to a garage foe repair. After that was repaired it was almost Christmas, and Covid was about, and I couldn't get a test until the end of February. It failed the test due to a very, very minor leak on the ower steering pipes. When I had a look underneath later I also noticed that the gearbox oil cooler was leaking, and an ABS/Traction control message appeared on the dashboard display.

So a trip to Edinburgh took place to pick up these parts. They were fitted the day before yesterday, Monday, and everything looked OK for an annual road test repeat. Until I was close to my house after collecting the car from the garage, when the ABS/Traction control message re-appeared. The evening before the annual test - again. I am sure the dopey blue donkey really doesn't want to be tested.

So first thing this morning, get under the car with a plastic head hammer and give the new sensor a couple of thumps. Give the car a run around for twenty minutes or so and finally, success. No ABS/Traction control message. For now !!

Pierre3.

Good news. The problem with hammering is that you can damage the dimple on the metal end of the sensor and the gap will then be wrong forever. The sensor should fit firmly/ snuggly in the housing (without hammering), so that after you put it in it can then self-adjust the gap.

I didn't do too much bashing at the head of the sensor, just a few taps. I can't be certain but I thought that I noticed the sensor move a bit on the first tap. Anyway, the warning lights are out for the time being.

I thought that, reading a lot of info elsewhere, that even if the sensor was pushed too far in then the rotation of the wheel would push it back out to maintain the correct spacing. Perhaps I have this wrong.

Pierre3.

No you aren't wrong, that is perfectly correct. The sensor is pushed in as far as it will go and on the first rotation of the wheel it is pushed out to the correct place. Once it is in and with the spacing correct, it should stay there.

all ways push the sensor as far in as you can when you drive it will push it self to where it should be

OK, thanks for the information.

Happy that my dashboard display is clear again - for the time being !

Pierre3.

Gilbertd wrote:

If it was a petrol car, up to 98 model would be Wabco C, 99 and later would be Wabco D. I would assume the diesel changed at the same time but can't swear to it. Wabco D has 4 wheel traction control if that gives any clues.

I have a 96 petrol, and am dreading doing the Russell brake actuator rebuild. What would happen if I just put in a later Wabco unit (I have one off a '99 and another off an '02). TY

You need to swap the ECU and do a few wiring mods, but swapping to Wabco D is possible, theres a writeup for the swap floating around but i dont remember where.