Thanks Steve,

The little wrench symbol is displayed for 20 seconds in the location where the digital trip milage would be. The mileage next to the symbol is counting down. There are no lights involved just the mileage indicator.

No not quite.

According to this scan of a December 1997 S320 german manual,
it should be;

1. Key to pos 2 and quickly press the button 1 twice inside a timespan
of 1 sec.
2. The last Service mileage lights up.
3. Turn key back to pos 0 before 10 sec since step 1.
4. Press button 1 and turn key to pos 2 again.
5. Keep holding button 1 until you hear a beep (10 sec)

My german is not that good, so mistakes in the translation
can be (and probrably is) present.

Here is the scan also:

http://www.pvv.org/~syljua/merc/FSSResetGerman.jpg

br,
syljua

Thanks Syljua,

The sequence worked...

Note to 'SoftConsult':
On my '96 S320, when I turn the key ON, (and BEFORE trying to start the car!) ALL OF THE LIGHTS on the bottom edge of the instrument panel light up (It's a check that ALL of the bulbs are working). The one on the very far right end (USA car) says 'CHECK ENGINE'.

If yours never lights up, mayhap you have a burned out bulb. I am sensitive to this because I once bought a car with that very bulb burned out - and when the bulb was replaced, lo and behold, there was a 'check engine' condition existant (cost me about $100)!

Farrell