auto box won't shift down

[barrygoodchild]

Good evening everyone,my gearbox has started to mess around, it won't shift down to second or first when needed, seems to go from fourth to third, had to come home bypassing a steep hill the other day because I didn't think it would make it to the top ! any idea's please ?
638 v220 by the way.

 

[deian]

personally i'd get the fluid changed, but get a STAR on it first see if it says something

 

[barrygoodchild]

hi, changed the oil last summer, what do you mean by "star" ?

 

[barrygoodchild]

should have mentioned, did a 100 mile run in it on the Saturday,which had no problems, it stood for a week, then went to use it and that's when this fault showed up, electrical maybe ?

 

[deian]

the Mercedes diagnostic computer, the one dealers have but enthusiasts on here also have, it should be able to tell you what's wrong.

 

[BlackC55]

It could be a number of things. As above. It needs a Star.

 

[BTB 500]

As an aside, IIRC the 638 (being FWD) has a non-MB gearbox?

 

[BlackC55]

Made by ZF

 

[barrygoodchild]

evening, had it put on star yesterday, and nothing came back? the guy said that there is a valve on the back of the gearbox that can stick, and guess what, it's a common fault! omg, if I had a pound for every time I heard that in relation to the vito
anyway, it may, or may not come unstuck, but if it doesn't then its a gearbox out job, oh deep joy......