W220 S Class 320 CDI loss of drive from transmission

[nikolaymk]

Hi,

I had quite a moment on the M25 today when my S320 CDI without any warning lost drive. All I felt was complete lack of throttle response before the car coasted to a halt. With the engine off drive was restored but only for a few hundred yards, then lost again. I tried this a couple of times and called recovery at the end.

The car is in the garage, trans oil level is ok, oil quality looks fine (they'll change it anyway) and Snap On diagnostics showed the following transmission codes:

P2222 Signal of Y3/6b1 or Y3/6S1 implausible
P220A Y3/6N2 - Y3/6N3 Speed Compar implausible
P2203 Y3 / 6N3 Speed sensor 3 faulty
P2561 The gear is implausible or the transmission is slipping
P2500 Transmission has impermissable transmission ratio

All faults were cleared and now the car sometimes gets drive or reverse for a short time after engine start up and sometimes doesn't although none of the above fault codes are now present.

Does anyone have any thoughts? Would a duff torque converter or even valve body cause these symptoms? The car is a 2006 55 reg S320CDI with 120K miles on the clock and the 5 speed tiptronic box.

Thanks for your help.

Nick

 

[whitenemesis]

Transmission Electroplate failure. Quite a few threads on the subject.

Not too expensive if you use an independent Merc specialist

 

[nikolaymk]

Hi, many thanks for the quick reply.

Found the thread below and will have a look, I was hoping it would be something electronic rather than mechanical. If our normal garage can not tackle this job can someone recommend a good independent specialist in West London, Park Royal or Middlesex?

http://forums.mercedesclub.org.uk/showthread.php?t=118781

 

[television]

WG is in Harrow and very good,,, it cannot be the valve block,,, the speed signal is an odd one as the car normally drives OK but locked in second.

 

[Steve@Avantgarde]

If the electro plate actually fails it usually goes into limp mode, you dont lose drive. So i dont think it is the electro plate.

However the fact you have a leak, will bring up the slipping fault codes and the implausible transmission ratio. I would flush the box and drive it. If its still slipping or falls out of 5th gear then something internal has failed, possibly the K3.

 

[Irresistance]

Has the transmission been acting "weird" in the few days preceding this incident? Shifting too late, clunking, making an unknown noise, etc...? It would seem improbable to me that something mechanical would "just break" and immediately fail... my bet is on the electro-plate failing.

 

[television]

I am with Steve on this one, I do not think so,,, we will see

 

[WG M-B]

If it gets drive after switching off for a short while then loses it altogether I would think that the filter is being blocked by debris in the transmission which is starving the primary pump of oil.
Just from experience I say this.
Call me if you need any further help 0208 863 9233

 

[nikolaymk]

There were no other symptoms from the transmission before this loss of drive today but my mind has been on other things so I wasn't paying attention and could've missed them. When your car stops the way mine did today it gets your attention though. I'll call WG tomorrow and we'll keep you updated. Thanks for all your help!

Nick

 

[WG M-B]

Any news?