Working on this really nice 1992 300SE with 115k and in good shape. I got it cheap and have fixed somethings so far and make some progress. Right now its still switches into limp mode from about 1 to 4 minutes after start up. A quick cycle of the ignition with reset it out of limp mode again.

It is a M104.990 with a 722.502 5-speed.



So far I have

Replaced Main Engine Harness (Old one was trashed)
Replaced Throttle Body Assemby ( Codes indicated faulty)
Replaced Gas Pedal Accelerator switch (S29/3 Codes indicated faulty)

So far I have noticed what seem to be minor improvements but it still goes into limp mode. I do have a Mercedes STAR/Xentry diagnostic tool and have cleared many of the codes.


Now I have code - 009 Control Valve Y3/1y2 remaining.

The diagnostic chart for this pretty much says, check wiring, check TCM and check control valve. Has anyone else dealt with this.

I have ordered a used TCM for next too nothing and will try that..next......


Thanks