Not always starting first time..service has been done..problem still there

replace air filter, clean fuel injectors, and replace fuel filter see what happens.replace spark plugs and wires.

how about the fuel filter. I didn't see this on your list and it should be done every 20000km and the air filter. I think its a fuel filter. not the pump. could be the coils but I would start cheap and change fuel filter first. when the pump is cold it pumps with more psi to blow passed the clooged filter after warm it is weaker and has a hard time pushing through the clog

Fuel filter,air filter,clean throttle body,what you have coils or cap.

well that is how I always sell a timing belt job also. The water pump is driven by the timing belt and it is very labor intensive to replace. I always replace the water pump also because you have to remove the timing belt to replace. I have had people refuse the water pump, and have to spend the same labor dollars a few months later when the pump went out. Even if not leaking it is always good insurance to replace the pump with the timing belt but is not a must just good idea.

It is high time to see that your car had a decent maintenance done on it as it has served you 110K miles. Please get this necessary schedules of work done with replacement so that it will continue to give you many more years of service.
Some tips for poor start and performance.

http://www.fixya.com/cars/r5843031-tips_check_car_not_start

Porvided the service maintenance was done accorrding to the scheduled list prescribed the car must be always in trim condition.
so check out the missed service points to go back and correct.
make sure the timing, tuning and replacement spares were done according tothe mileage or the time .
If so your car must be in good condition unless if your service dealership work is below level,

I have the same car and while it has never givne me this problem when I got the car serviced last year (Sept 09) in a mercedes garage they replaced the battery with an upgraded battery. This was done foc as part of the Mercedes care programme. I've always gor my car serviced in a Mercedes Garage.

Hope this helps
Richard

Hello. most times you reset by turning on the ignition but not starting the auto, then quickly push the gas pedal three times. J.

there is a rocker switch at the end of the wiper switch that goes up or down, tap that several times at it will start toggling through the different modes on the display when you get to the maintanance mode and then press the reset on the bottom of the wiper switch

that could be alot of things... does your car run well...? has your engine been service lately?? is it time for your routine maitnance done..? plugs, Wires , oil,,., if all is well its always easy after all is checked? is to simply get the computer connected at a shop to find the code your light poped..