Difficulty resetting "Service Due Now" on 99 Wagon
 

I followed the direction on the manual to a "T", and even followed all the other advices mentioned on this forum like:
1) close all doors
2) wait for hibernation mode of the car to kick in before resetting
3) holding down the "O" button during position 2, going to Position 0 with the button down, and then back to position 2.

FYI, I've been ignoring the message for months now. Now that I've got some time to sort it out, I'm obsessed with clearing it. Pleae help!

PS: I have a 99 E320 Wagon. Thanks.

Sometimes it takes several tries, although I cannot fathom why... I don't have to wait for hibernation mode when I reset mine, I just close all doors (important and NOT in the manual) and follow the directions. I know right away if it's working or not based on the "Display oil level?" prompt. If I get the prompt it's not taking and I have to try again. Make sure you observe the timing requirements in the instructions.

No, don't wait.
get in car, doors closed.
key to ON
push button twice so FSS mileage or time remaining (or over)displayed.
push down AND HOLD button
key off (do NOT release the button!)
key ON and wait 10 seconds or until beeper beeps and FSS is reset.

alternate:
get in, doors closed
key to ON
push down button twice so FSS mileage or time remaining (or over) displayed
key off
push down AND HOLD button
Key to ON, (do not release the button!) and wait the 10 seconds or until it beeps.
Only problem I see is what if the door switch is broken so the cluster isn't activated? Hmmmm. Check the door switch to make sure it's there, it's by the door striker on the body.
Gilly

Gee, Gilly... I never thought about a broken door switch. I'll check that one out.

Would be pretty obvious, the interior lights won't be working, but someone would have turned the switch in the dome light assembly off. Those switches to break often enough, fall right into the B pillar.
Gilly

Mr Gilly, you were right! The switch tab was broken. I did get the switch to work, and now I managed to reset the FSS. That also fixed the problem I was having with the power lock not working. Thanks a bunch!

Now that I want to replace that door switch, what would be the best method of access? Do I need to remove some interior panels from the pillar to replace it?

Not a bad job. Usually you can just get it by pulling the weatherstrip out of the way, then there's enough gap to get the old switch out in that gap. After that's out it's a piece of cake, you'll figure it out w/o any instructions.
Gilly

So you probably has the interior lights shut off at the switch on the domelights too? This will make that all work correctly again when you're done....
Gilly