Snow tyre clanger

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Burnerman

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Thought I was being clever :p
Fitted some snow tyres to 'er indoors Nissan Note (15" Alloys).
Couldn't get any 15" rims as spares, so got 2 14" steel ones which fit perfectly.
I chose a 14" snow tyre with a high aspect ratio, to accommodate the reduction in rim size.
The ABS light is now on :eek: so it seems that the ABS system accounts for the tyre rolling radius, sees a slight difference and doesn't like it :oops:
Just when you think you know what you are doing.......! :confused:
John :)
 
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I would suggest the problem is a disturbed connection at the ABS sensor, does the ABS light come on before vehicle actually moves?
if so, then it's nothing to do with the tyre size change.

Wotan
 
My own sentiments exactly! However, the fitters were gentle with the wheels, jacks in the correct place etc and all wires are intact.
I thought I had sussed it, because lets say the rims are different diameters. The ABS thinks that they are rotating at different speeds, doesn't like it and puts the ABS lamp on. Fair enough.
When I switch off the car, the light stayed off for a while then came back on. I was doing 70+ mph on a dual carriageway. This happened twice. I came home and switched off.
Now, I've been out for a 50 mile drive. I haven't been over 65 mph and the light has stayed off. The ABS is working, too.
I realise the ABS has to recognise a wheel diameter tolerance due to tread wear and tomorrow I'll check the wheels out, side by side. They look as near as dammit the same diameter though!
Still a bit confused, but more than happy if the light stays off. Excellent tyres too! £75 each so the manufacturers know they are on to a good thing.
John :)
 
Sounds as though the overall diameter is about the same with your choice of tyres John, if not could it be comparing the front/rear rotation speed? Not a problem I have come across - or perhaps it is just encouraging you to save fuel :D

Peter
 
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I think yonder Nissan must be doing just that, Peter - comparing front wheel and rear wheel speeds.
No matter - if the ABS light remains off, no problem but if it does come on then the ABS is disabled and I don't think I'll be so popular with Mrs B.
(She's driving a Jimny just now - latest aquisition).
I suspect your BMW won't like the snow, particularly! :D
Be safe in this weather and don't overdo the lastest antifreeze tipple ;)
John :)
 
BMW gone now John, didn't like it, got a 406 Hdi now after saying I would never have one :oops:

Peter
 
Burnerman said:
My own sentiments exactly! However, the fitters were gentle with the wheels, jacks in the correct place etc and all wires are intact.
I thought I had sussed it, because lets say the rims are different diameters. The ABS thinks that they are rotating at different speeds, doesn't like it and puts the ABS lamp on. Fair enough.
When I switch off the car, the light stayed off for a while then came back on. I was doing 70+ mph on a dual carriageway. This happened twice. I came home and switched off.
Now, I've been out for a 50 mile drive. I haven't been over 65 mph and the light has stayed off. The ABS is working, too.
I realise the ABS has to recognise a wheel diameter tolerance due to tread wear and tomorrow I'll check the wheels out, side by side. They look as near as dammit the same diameter though!
Still a bit confused, but more than happy if the light stays off. Excellent tyres too! £75 each so the manufacturers know they are on to a good thing.
John :)
Click to expand...

Absolutely NOTHING to do with wheel dimensions. I've had, and know of loads of other people, with non manufacturer spec wheel/tyre combos, and NEVER came across this. My car has, as standard 15" alloys, think it's 165/70/15, but currently has fitted 215/40/17 (the tyres are like rubber bands), never an issue with ABS. It knocks the speedo reading out, but not the ABS. A sensor has been damaged, which means the ABS isn't working, so if you continue to drive it, and have an accident, you won't be covered by insurance. However the ABS system can be diagnosed to which sensor is faulty, in some cases by the user, but in this case sounds like OBD-II system, which requires a laptop hookup, by the dealer, to reset, or trace. Replacing the EFi fuse, or disconnecting the battery 'might' reset the problem.
 
Sorry Micky - its as I thought. The front wheels are spinning faster than the rears and the speedo is reading 8 mph fast at 70.
The ABS is noticing the difference in wheel speeds, and gets grumpy accordingly.
If I stay below 65 MPH the ABS light stays off. Above this speed for a distance of over 1 mile the light comes on and stays on. The light resets when I switch off.
I do take your point about the insurance issues and next time I'll have to get 15" spare rims and the same size aspect ratio snow tyres. In the meantime I'll chance it.
The rims I'm using are spares from a K12 Micra (14") and as I'll have one of these for sale in March I'll consider selling these rims and tyres with the car.
John :)
 
So the tyre profile between front and back is different? Sorry, didn't realise that. I think there are a few production cars that do that, but not the norm, the ECU must be programmed to take that into account. Surely fitting a spacesaver would give a similar result? If that is the case? I never heard of the profile causing an ABS issue, and been member of car clubs since the '80's.
 
Obviously its all to do with the fact that ABS systems are getting even more sophisticated as developments progress - I'm sure this wouldn't have happened with the XR3i belt from driveshaft arrangement!
So, I've found to my cost that the tyre diameters have to be the same, give or take the tolerance found with tread wear.
So, its a 200 quid learning curve for me but as I'll get one winter out of these tyres I'll just flog them on after.
John :)
 
Mickymoody said:
My car has, as standard 15" alloys, think it's 165/70/15, but currently has fitted 215/40/17 (the tyres are like rubber bands), never an issue with ABS. It knocks the speedo reading out, but not the ABS.
Click to expand...

Not sure whats going on there but
you would be better off with 225/40/17 as that has the same diameter as the 165/70/15. you are currently -1.3% smaller so you have a lower top end ( all off 1.3%)
To and extreme if you fitted truck wheels the abs would not fault as the wheels all are rotating at the same speed however the speedo will be a "smidge " out lol
if the rear is smaller or larger the this will bring on the ABS light.
As it works by comparing the wheel speed sensors signal.
However odd it looks the space saver probably has a similar diameter as the rest of the tyres and at a max of 50mph would not bring a fault light on

My previous car ran 16" rim( on in the range ran14") I went to 18" and 19" at does not matter providing you get all the ratios correct
 
Don't forget, the ABS speed sensors are on the driveshafts (or c.v joints) on the front, so they are monitoring the rotational speed of the shafts not the wheels. The system will compare all the sensors, front and rear, and will compare them. Any discrepancies, and the light will be on. I doubt very much if the driver would notice any difference in the braking performance of the car under normal driving. It's just a physcological thing when you see the light on. I think you've pretty much got it sussed now John, so I'll leave it there.
 
Does that mean the wheels are turning at a different speed from the shafts?
 
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