hi guys
I know the Mercedes 5 speed is supposed to start in 2nd in normal mode but I thought it should start in 1st when in s mode.


if im in s and take off its in 2nd and it will drop to first if I really shoe it but any kind of normal/ slightly fast takes off and its in 2nd.would this suggest my s mode is not working ?


I ant notice any difference from when its on and off really. is there any way to check? the little red light doesn't come on either

 

Where did you get the info that it starts in 2nd. The one that I drove clearly had five speeds in N. If the light is not lit it may not be in S. You should be able to see the difference in shift points under low throttle application.

 

If the light isn't on it maybe either,
1) led in switch burned out
2) Defective switch

Do you feel the switch changing ie when pushed down does it lock in the down position and when 'on' is in the up position ?

 

the switch is locking, can now confirm the sport mode is not activating, im thinking it may be a control mod fault.

 

From the JTIS

The performance mode pushbutton:Is mounted on the 'J' gate surround.This 'push-on push-off' switch selects Normal or Sport mode ( push-on for Sport)Is illuminated when Sport mode is selected.Is hard-wired to the transmission control module.With 'Normal' selected the transmission will start off in 2 nd gear with kickdown to 1 st being available.'Sport' mode allows 1 st gear engagement from rest and modifies values in the TCM shift point calculations to provide higher upshift speeds and enhanced availability of downshifts.


So try a kickdown and see if the tranny jumps to first, 50km / hr then floor it
Also you might pull the shroud and check the connection plug on the switch.
I've been reading here (JF) for 2 years and haven't ever seen / heard of this specific problem to be a TCM

 

the car will kick to first , but sport mode does not engage

 

You might consider performing a hard reset this will reset the shift points to factory and the trans will relearn your driving style. Pull NEG batter lead off it's terminal, touch it to the positive battery post and hold there for 15 secs, NOTE: you will need to reset the window(s) travel, with key on hold window down button till you hear a beep, then hold up till beep, and you may have to enter your radio security code so ensure you have it avail before the reset.

(and do check the switch connector with your eyes, previous owners do crazy things it's the easiest thing to do, pull the surround and ensure it's fully seated)