tommymercedes

I just purchased a 1999 Mercedes Benz E320. It is in impeccable condition with over $22,000 worth of dealer and specialty shop maintenance/repair records (I have accounted for via receipts). The owner decided to part with it after purchasing a new car. This car was purchased in Germany and exported into the United States by the original owner (who sold me the car).

Now to the bad stuff. I purchased the vehicle knowing it had a bad transmission, but not knowing to what extent it was damaged. My dad had a backyard mechanic that fixed another vehicle lined up. However this Mercedes transmission seems like a more difficult feat.

On a regular OBDII scanner I am getting the code p0730 "Incorrect Gear Ratio". The car will go up to 40 mph at 4k rpms (pushing it), cruising around 30mph at 3k rmps. I am not sure if this transmission issue is purely electrical or mechanically faulty. You can hear the transmission shift when you put in drive, reverse, etc (it will shudder).

The backyard mechanic says that the plate (sounds like the conductor plate?) which I have been reading online, may have gone bad as that goes bad on this type of vehicle.

I have a few concerns. First off what does my issue sound like? Second off the previous owner had repairs done to no avail, if the car was running in limp mode, would it have to be manually reset at the dealership to make it run again, had the repairs been effective?

I am waiting to pick up the car at the local MB dealership, it is currently having the transmission "diagnosed" on their computers, at the cost of $135 (not sure if it is a good deal). The MB guy says common problem is the "valve body".

Regardless, if the diagnosis points to a culprit, when my backyard mechanic replaces/rebuilds the trans components, will the car have to be taken back to the MB dealership to have the computers "reset/synced"

Sorry for the lengthy description. Reading these forums it seems more of a common issue, however mine does not sound like the rest.

obinna.ejim

My problem is exactly yours.
Please I would like to share on your knowledge.

RichardM98

The driving symptoms seem to indicate the transmission has gone into what is called 'Limp Home Mode'. A condition which only allows one forward gear and reverse and limits rpms to around 3-4K. It's purpose is to prevent damage to the transmission. The cause can be electrical, mechanical or both. The dealership diagnostics should help identify the specific cause.

Unless the transmission's control unit needs to be replaced, a recoding of the transmission shouldn't be necessary.

Plutoe

Don't be foolish----"share information" How do you know you will have the same faulty part??

If you want correct information on your fault you need to have the transmission scanned by MB software or maybe carsoft. All else is wasting your time and money!!

Bart989

Hi
This info maybe irrelevant to this question but i want to add this link for people who has a transmission issue with older e-class MB
I was replacing pressure spring on the valve body and accidentally dropped check ***** some plastic some steel. The link below will help you sort out most DIY jobs you take on with e320 722.6 transmissions. http://www.scribd.com/doc/37436253/722-6
Thanks

EricGV

With the valve body is the electo-plate. Electronic PC board controlling the transmission. I replaced mine at a friend of mine's garage, he used to work for MB and after restarting the car went into a limp mode, left me driving to closest MB dealer in 1st gear and they had to reset the system and load the new part with a modem link to Germany. The way I understand is like you fit a new piece of hardware to your PC. You need a driver to use it properly. Whell problem soved. MB had to do some nifty moves on their system, and only they can do it. Hope it helps.