car won't shift

[whitcre]

just had a/c worked on. when i picked up the check engine light was on and it wouldn't shift out of 1st gear. 97sl500 85,000 miles. any ideas

[nobby]

The first thing that comes to mind is BRING IT BACK.

[Roncallo]

My 88 560SL did this for a day and then it just started working again.

John Roncallo

[beejn]

It sounds like a problem I had with my 98 sl500.
I had the control module in the tranny replaced and that solved the problem..

Hope Im wrong because its an expensive proposition....

[whitcre]

im thinking something got unplugged. are there plugs or vacuum hoses close to a/c lines when the mechanic was checking the system or adding freon?

[whitcre]

im thinking now that it might be stuck in 2nd which i guess is the limp home mode. what are rpm's at 30 mph in 1st or 2nd gear? if its stuck in "limp mode" would the "check engine light" be on or another light on? also, putting in "w" had no effect

[bobterry99]

Originally Posted by whitcre

im thinking now that it might be stuck in 2nd which i guess is the limp home mode.

No doubt about it. The transmission ECU needs to be scanned for diagnostic codes, the cause of the limp mode needs to be corrected, and the code(s) need to be erased. An advanced scan tool that would typically only be had by a repair shop is needed for this.

The electrical connector at the transmission is a likely culprit, these are very bad about leaking fluid into the wiring harness all the way up to the control unit. I have fixed this problem on a couple of cars by replacing the trans connector housing on the transmission ( unplug the trans and it is held in by one 7mm bolt in the center of it) dont forget to check the trans control unit for fluid in the connectors. if flluid is present just clean it all out and I have fixed several like this. In fact MB shops do it all the time. with no come backs. If that is the problem of course