S210 gearbox conundrum

[rascalmaster]

Hi all.

my wife's S210 E320 petrol, seems to have a peculiar affliction.

on cold mornings; when we start and drive off (with or without warming up) the car seems stuck in 2nd gear.

after a bit of a drive; if switched off and allowed to rest for a few minutes; it reverts back to smooth and silky gear changes!

this has happened on 2 occasions now; both times the outside temp was well down to only a couple degrees.

what gives??

BTW, I had called Olly at PCS when it first happened a week ago; and he said that it might be one of a few things, but i should check the battery.
well i have charged it fully over 24 hours using a Cteq charger...

I haven't been back onto Olly, being the weekend, but here's hoping some pundits can shed some light on this in the meanwhile.

Thanks in advance.

 

[Dieselman]

Is it actually stuck or just holding 2nd gear to get the Cat to heat up faster?

 

[rascalmaster]

well i have been driving at 35 mph and it still wouldn't change :-(

I kno my 211 e280cdi does hold gears to ensure a higher rpm to help the cats along..

 

[rascalmaster]

any other thoughts, gents?

 

[230K]

http://www.mbclub.co.uk/forums/engine/118769-sl500-stuck-2nd-gear.html

Might be of help????

230K

 

[Alex Crow]

+2 for the battery, it fits the symptoms perfectly. A fault code read out is usually conclusive for this fault.

The issue is the volt drop on startup, if the battery is worn it does not matter how much you charge it, its voltage can still dip below a critical level on cold starts (around 8.5v) - especially at low temperatures...

The gearbox control module sees this volt drop beyond a given point, logs a current fault code, and refuses to attempt to change gear as a precautionary measure. When you restart it the engine has warmed slightly, and the battery has had a very recent 'boost', so the volt drop is not as much as before. Then the fault code goes to 'stored' status, and the control module allows normal operation.

A fault code read out is the way forward, obviously.

 

[rascalmaster]

super stuff.... thank you very much.

all fingers are pointing to la batterie...

 

[rascalmaster]

Just to let you all know; £108 and a new original high capacity battery later; the gremlins are gone!

thanks all