ABS light & Auto box problems!

[Geoff W]

Hi Everone.
This is all new to me , but here goes!
I have a 1997 C180 auto classic, 50K, whilst driving today i heared and felt a dull thud, immediately followed by the ABS light coming on, and then no gear change at all. I had to limp home with one forward gear (no matter where the selecter was).
After reading the handbook i presume the gearbox had gone into emergency mode? If so could this be a automatic safety measure because the ABS had illuminated?
I'm hopeing this is either a brake fault, or a faulty sensor, as the two problems occuring together seem too much of a coincidence.
Before this problem everything was perfect, no braking problems and the gearbox has been excellent.
I would appreciate any help before i reach for the Cheque book.
Regards geoff.

 

[television]

Hi Everone.
This is all new to me , but here goes!
I have a 1997 C180 auto classic, 50K, whilst driving today i heared and felt a dull thud, immediately followed by the ABS light coming on, and then no gear change at all. I had to limp home with one forward gear (no matter where the selecter was).
After reading the handbook i presume the gearbox had gone into emergency mode? If so could this be a automatic safety measure because the ABS had illuminated?
I'm hopeing this is either a brake fault, or a faulty sensor, as the two problems occuring together seem too much of a coincidence.
Before this problem everything was perfect, no braking problems and the gearbox has been excellent.
I would appreciate any help before i reach for the Cheque book.
Regards geoff.

I think that you have an OVR if this has gone or the fuse on top, you would lose the ABS and the car would not run so good with the electrics down to 7.5 volt.

malcolm

 

[Geoff W]

Hi Malcolm, Excuse my ignorance, i am new to this, but what is a OVR?

 

[television]

Hi Malcolm, Excuse my ignorance, i am new to this, but what is a OVR?

Its the over voltage protection relay, its main pupose is to protect the expensive electronic modules on the car, should the 12volt system voltage rise.


Malcolm

 

[Geoff W]

Its the over voltage protection relay, its main pupose is to protect the expensive electronic modules on the car, should the 12volt system voltage rise.


Malcolm

Hi Malcolm, thanks for the help with the suspect OVR, i have had a delve into the relay compartment, but despite consulting both handbooks and Haynes, I cannot assertain which one is the OVR relay, is it just a case of buying a new one and matching it up to the existing one? I have checked the fuses and all seems OK.
Many thanks for the help, it is most usefull.
Geoff.

 

[television]

One thing that I cant do is to ask you to go and buy a new one, it should be checked out first. the web link will show you where it is, Item128

There is a fuse on top of thr relay that could have blown
Malcolm

http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=54&SGR=045&SGN=03

 

[Stevie A]

Have a look in your MB manual for why ABS light comes on. I'm with Malcolm, but the dull thud sounds like potentially a mechanical problem. Best to bite bullet and pay for a diagnostic test at a dealer. Or try reseting the car, but you'll need someone else to tell you how to do that.

If limp mode on you car is just one gear then you may be lucky.

 

[C220GJS]

Ovr.

The OVR on your car is located in the Ecu compartment at the passenger side rear of the engine bay. It is a tall silver relay with a fuse/fuses on top, it is held in place by one screw and has a wiring plug in the base.

 

[Geoff W]

Thanks!

Thanks everybody for your help, the problem is not yet fixed but i will check out all the advise tomorrow and report back with the results.
Regards Geoff.

 

[Geoff W]

Hi Everyone.
Had a good look under the bonnet today, removed the lid on the Ecu to locate the OVR, looking for a tall silver relay with a fuse on top, but could only find a small black square relay with a 40 Amp fuse located alongside it, am i missing something really obvious?
I would willingly have a diagnostic test but the problem is getting to the experts premises with only one gear! I suppose i will have to trailer it if no luck.
Regards Geoff.

 

[jimsinessex]

I'm with Malcolm, but the dull thud sounds like potentially a mechanical problem.

On my 1999 CLK 230K I had "dull thuds" shake the whole car when accelerating hard and the MAF sensor failed and went to into limp mode and again when a rear wheel speed sensor failed under braking and knocked out the ABS and the dash lit up like a christmas tree so it could still be an electronic related fault. As above a diagnostic is the way to go.

Good luck, Jim

 

[khanie]

As you live in Chesterfield, look in the yellow pages for a garage in Stanfree near Bolsover. I think its called Duma? but may be completely wrong. They are an Indie MB specialist with a good reputation.

Hope this helps.

 

[Geoff W]

Thanks for that Khanie, I have actually contacted them today and booked the car in! They are called Damas Ltd on 01246 822939.
I could not find the OVR as described anywhere, so i gave in and rang them, they are collecting the car on Saturday, I will post and let you all know what the diagnosis is.


Many thanks Geoff.