Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Jan Suhr on 25 March 2018, 06:41:46

Title: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 25 March 2018, 06:41:46
After just a few hundred meters the ABS and TC light came on.

I read elsewhere on this forum that different tire sizes can cause this. I have 245/35X18 profile in front and 245/45X18 profile in the rear.

I guess this is the cause of the lights coming on. Is there a way to fix this or do I have to buy new tires for the rear. Reason for the difference is that the 45 profile are to tall for the front and hits the struts spring pocket.


Thanks

Title: Re: ABS and TC light came on, different tire size?
Post by: Doctor Gollum on 25 March 2018, 08:03:39
245/40/18s all round on Omega 18" wheels... 235/40/18 also acceptable
Title: Re: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 25 March 2018, 08:38:41
Well I'll check with a set of 17" wheels I have to see if the ABS light comes on with them or not. Then I will get 2 new tires so I have the same all around.

Then I have to find some one who will buy 4 brand new tires, the ones that don't fit  :-\

Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 25 March 2018, 11:17:56
Had you just had the tyres replaced? If so, this can happen, and takes about half a mile to learn the new tyres. Proper learning procedure is in the glovebox handbook.

If the tyres have been on for a while (more than a few miles), then you have a fault.  Did the speedo die at the same time?
Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 25 March 2018, 11:21:05
245/40/18s all round on Omega 18" wheels... 235/40/18 also acceptable
Vauxhall do not state any size for 18", as Vauxhall never provided any 18" rims.

Even 235/40/18 tyres can rub the strut or wheelarch (depending on camber settings), depending on their shape, such as the god awful GY F1 Assym2
Title: Re: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 25 March 2018, 13:18:07
Had you just had the tyres replaced? If so, this can happen, and takes about half a mile to learn the new tyres. Proper learning procedure is in the glovebox handbook.

If the tyres have been on for a while (more than a few miles), then you have a fault.  Did the speedo die at the same time?

Yes the tires and wheels are new and never driven on before. Drove it yesterday a few kilometers to get the paint polished. So I guess it is just a matter of different diameter between front and rear.

Car has only gone 170.000km.

Thanks
Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 25 March 2018, 14:45:19
In that case, it would have sorted itself out by now :y

You may get similar if/when you change tyres again, just while ABS ECU learns the new rolling diameter of each tyre.
Title: Re: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 25 March 2018, 14:48:05
Thanks you saved me €300 on two new tires  :)
Title: Re: ABS and TC light came on, different tire size?
Post by: DrAndyB on 25 March 2018, 15:42:36
Had you just had the tyres replaced? If so, this can happen, and takes about half a mile to learn the new tyres. Proper learning procedure is in the glovebox handbook.

If the tyres have been on for a while (more than a few miles), then you have a fault.  Did the speedo die at the same time?

Oooh, that I didnt know  :o

Is that All Omegas ? or just the Facelift Model ?
Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 25 March 2018, 16:02:40
Certainly all post 98, but suspect all
Title: Re: ABS and TC light came on, different tire size?
Post by: neil74 on 25 March 2018, 16:13:40
My ABS TC lights and the speedo work and don't work whenever they feel like it. and the steering has moods on it when it gets really difficult to steer but after I leave it a while it normally comes back to normal..
Title: Re: ABS and TC light came on, different tire size?
Post by: Entwood on 25 March 2018, 16:23:28
My ABS TC lights and the speedo work and don't work whenever they feel like it. and the steering has moods on it when it gets really difficult to steer but after I leave it a while it normally comes back to normal..

Well known problem, there are a couple of places that will repair the ECU for you .. :)
Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 25 March 2018, 17:15:58
My ABS TC lights and the speedo work and don't work whenever they feel like it. and the steering has moods on it when it gets really difficult to steer but after I leave it a while it normally comes back to normal..
If yours is post 98, that does sound like a classic ABS ECU failure.

Either replace for known good (from same engine/gearbox combo in order to avoid Tech2 requirements), or send off for repair.


If pre 98, get the codes read on the engine, gearbox and ABS.
Title: Re: ABS and TC light came on, different tire size?
Post by: neil74 on 25 March 2018, 19:13:30
Can someone give me a rough idea what it would cost to repair it?.
Title: Re: ABS and TC light came on, different tire size?
Post by: Entwood on 25 March 2018, 19:40:35
Can someone give me a rough idea what it would cost to repair it?.

Its a few years back now .. like about 12 !! Mine was done by BBA Reman and cost £130 with a 2 year warranty ... no doubt the price has changed since then !!

BBA Reman site ...

http://www.bba-reman.com/gb/index.aspx

might be worth giving them a ring for a price update
Title: Re: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 16 April 2018, 14:19:19
OK, I have taken her out now to be driven over the summer. Drove 13 km just now and the lights are coming on after about 800 meters. Stopped several times and turned it off. Lights came off every time and back on after about 800 meters.

I suppose that the difference in diameter between rear and front is too large for the ABS ECU to be able to learn how my wheels are.

I'll put on the stock wheels for now and I guess it will behave after that and then I have to get the same diameter tires for the rear.


Thanks



Jan
Title: Re: ABS and TC light came on, different tire size?
Post by: Doctor Gollum on 16 April 2018, 16:41:21
If it doesn't behave, then you know you're looking at a new ecu...  ;)
Title: Re: ABS and TC light came on, different tire size?
Post by: Jan Suhr on 16 April 2018, 18:14:31
No fault codes with wheels with the same diameter all around. So nothing wrong with the ECU, just me who doesn't buy the correct tires  :'(

So now I have to order two more tires with the same size as the fronts.

Between the rears and fronts there is about 40-50 mm difference in diameter. Must be too much for the ABS ECU to handle.

At least we know that now.


Jan
Title: Re: ABS and TC light came on, different tire size?
Post by: TheBoy on 16 April 2018, 19:15:38
Useful info Jan :y