Kleemann500

Hi.

Any experts on a 7G tranny that works fine, EXCEPT when doing kickdown. Car will shift down in gear, but then pops out in to neutral when hitting high revs, and tranny is still showing "D" mode. Engine off, then on, and car drives fine again. Oil and service is ok.

ItalianJoe1

Faults?

Usually an issue like that is a speed sensor fault, requires a new conductor plate, but if you have it scanned, you will know more.

Kleemann500

Hi.

Only fault on diagnostic is showing p2501 "Engine overrevving". It is tuned with kleeman stage 4.

ItalianJoe1

Would have to watch the actual values inside the trans computer when it happens then. Is the transmission upgraded at all?

Kleemann500

Hi.

How can you do that? No, transmission is standard. Everything works fine, manual shift, shift when accelerate without kickdown. Only mystery is going neutral in high revs AFTER a kickdown.

ItalianJoe1

Actual values require Star diagnostic system hooked up while driving. You can watch and see what actually happens when it defaults to neutral. Most of the time it's a speed sensor issue, which is serviced in the conductor plate. Have you ever changed it?

LARSLEMANS

I had the same trouble with my 7G tranny on my Kleeman 2005 CLS 500, and it showed a valve unit error on the diagnostics system.

After replacing the Transmission Computer Unit and recoding it, the tranny works fine.

(quite expensive in Denmark, almost 3 K EUR for a replacement unit).

You should look for an error code regarding the valve unit in the gearbox.

Kind regards
Lars Rasmussen