Hi people, I know nothing about this topic, other than it’s the Anti-lock Braking System for the trailer, and the ■■■■■■■■■ roundy shaped doodar pluggy thing!
Anyway, I took a trailer out the other day that seemed absolutely fine, but the moment I got up to about 50, I got an ABS warning on the dashboard. So I’d like to know a bit more about what is going on here!
I’d not touched the brakes as I was still getting up to cruising speed, and wondered how and why this fault hadn’t shown itself before. It didn’t even need me to touch the brakes to register, so exactly what is going on here■■?
i get it quite often and normally it is a pin / pins misaligned in the connection.
also sometimes it goes away on reaching a particular speed but it looks like you have the opposite scenario here. Never had a genuine fault with a trailer abs yet
Amber or red light?
Sometimes removing the ABS lead, swapping it end to end and putting it back in with a decent waggle and a squirt of something like WD40 (not many lorry drivers carry contact cleaner ) is worth a punt, but as its ok till you get up to speed its more than likely a fault with a sensor or similar, might even be water has got into the wiring.
It will probably carry on doing this till you write a defect out and the mechanic does his diagnosis, or stick below 50 if that’s the magic speed if you’d rather not see the light…
Sometimes a tractor and trailer don’t like each other, it might be perfectly happy with another unit make, we have one tank like this its been in umpteen times, perfectly happy behind another make.
Amber light would i worry?, not really but i’d take extra care and do a defect for it when i get back, others might feel different.
Red light its more urgent.
Are all the tyres correctly inflated and of the same size on the trailer ? if the error is being generated by a set mph speed difference then this would explain it occurring at a higher speed.
You then need to start checking the sensors, one of them could be giving off a dodgy signal, a good clean around them can sometimes sort them out, but probably one will need replaced.
It’s an Amber warning, and I’ll have a go at swapping the ends and giving it a clean, as I do carry a can of squirty stuff in my bag of crap (Which seems to get heavier and heavier! )
I’ve defected it, but doubt I’ll ever see what happens, as it’s pretty much a trailer merry-go-round at this firm…
The tyres all seemed fine, and I’d like to say they were EXACTLY all the same size, as they looked it. But I have to confess that I didn’t read the sizes to be absolutely certain. But as that could be a possible cause, I’ll be on the lookout from now on…
As for checking & cleaning the sensors, I wouldn’t know where to start!
I wouldn’t want to be buggering about with things that I don’t understand, and would presume this is more a job for the workshop.
Especially if a sensor needs replacing…
Evil8Beezle:
The tyres all seemed fine, and I’d like to say they were EXACTLY all the same size, as they looked it. But I have to confess that I didn’t read the sizes to be absolutely certain. But as that could be a possible cause, I’ll be on the lookout from now on…
.
not all tyres of the same spec (and same wear) are always exactly the same… If it is a tri axle, lay a plank of wood over the top of them, there shouldn’t be much of a gap between any of them, an inch gap would be big!
■■■■■■■:
The random abs warning light system was originally devised by DAF to aid driver nervousness.
This is a standard factory fitment on their units.
LOL - Can anyone recommend the best thing to clean cornflakes off my laptop screen!
Depends on the truck too .
Also the faults ping up if you leave the truck running or the ignition on when putting the suzzies on as the system gets a sudden surge of power.
As in your case it’s coming on at speed it could be a simple case of a bad connection , movement with the lines .
If it’s happening at the same speed all the time, and every time you hit that speed, it will generally be rust/corrosion on the exciter ring. You can sometimes get away with a quick fix of knocking the sensor closer but obviously it will keep rusting and that will only work so long. A bit of a wire brush can help or careful cleaning with a die grinder is even better.
Eventually though it will need a new exciter ring or sometimes a whole new disc depending on the axle design.
High speed dynamic ABS faults like this can be tricky for workshops to deal with as they will typically use electronic test equipment whilst spinning the jacked wheels by hand and at that speed the signal definition is still good enough for everything to appear ok. You do get other intermittent trailer ABS faults caused occasionally at higher speeds that can be caused by all sorts like a slight bit of bearing play combined with an odd bump in the road that will be even harder to diagnose but with them as long as they aren’t happening like clockwork everyday I wouldn’t worry too much.
Most drivers (ie in a permament job and not a limping drama queen) would probably continue with this fault, to the end of the shift, provided it is amber. While the light is lit there will definitely be no trailer ABS operating so if, for example, it’s wet and slippery if you take the opportunity to switch the ignition off and on again, when you next have to stop at a junction, you will have full ABS again until you next hit the speed that triggers the fault.
Sounds like a pole wheel fault, or a slack wheel bearing, it doesn’t take much to knock an abs/ebs fault up, the gap between the sensor and the pole wheel specs are something like 0.7mm, and if the sensor has moved back. And the pole wheel has been dented. It’ll throw up a fault.
BPW axles, are more prone to the faults your talking about than other axles. Due to there design.
I had an issue with the abs light permanently on with a trailer I pull , seeing as I’m the only one to pull the trailer I was keen to see it sorted .
Knowing how useless our " mechanics " are I wasn’t holding my breath
The trailer was going for mot , so though great it gonna be fixed now , only I
For it to come back with a pass and the abs light still on
Anyway after having words , they had a couple of attempts to fix it ,changing the sensor or sensors ,unsuccessfully at first of course
It was better admittedly and would only come on randomly after so many miles or on one occasion straight after being loaded
Anyway it seems to be behaving the past few times I pulled it
Interestingly today I had poke round underneath and noticed only the middle axles on each side have a sensor fitted , You can see the hole where the sensor goes in the other axles .
I would have thought all wheels would have a sensor fitted anyone shed any light on that one ?
Mikey D:
I had an issue with the abs light permanently on with a trailer I pull , seeing as I’m the only one to pull the trailer I was keen to see it sorted .
Knowing how useless our " mechanics " are I wasn’t holding my breath
The trailer was going for mot , so though great it gonna be fixed now , only I
For it to come back with a pass and the abs light still on
Anyway after having words , they had a couple of attempts to fix it ,changing the sensor or sensors ,unsuccessfully at first of course
It was better admittedly and would only come on randomly after so many miles or on one occasion straight after being loaded
Anyway it seems to be behaving the past few times I pulled it
Interestingly today I had poke round underneath and noticed only the middle axles on each side have a sensor fitted , You can see the hole where the sensor goes in the other axles .
I would have thought all wheels would have a sensor fitted anyone shed any light on that one ?
yep thats normal, there’s very few trailers around with more than 1 sensor on each side, i’ve been doing it 3yrs, and have only come across 2 trailers which had 4 sensors, and they were identical tankers.
out of interest, the trailer you pull, is it on disk brakes?
Mikey D:
Yes mate ,disc brakes can’t remember the make of the axles off the top of my head tho Cheers mike
depending how new it is, it might have tyre pressure monitoring system, and or brake pad wear sensors, both systems, i’ve come across a very little, but both can be interlinked with the ebs system, if they are, and there is a fault with either of the systems, it could throw up a amber warning, but i’ve seen a broken tyre pressure sensor throw a red warning lamp up.
) is worth a punt, but as its ok till you get up to speed its more than likely a fault with a sensor or similar, might even be water has got into the wiring.
You can see the hole where the sensor goes in the other axles .