JunoJim

We just got our new (to us) 1997 SL 320 - took it for our first long ride, and the "check engine" light came on !!!

I opened the hood, and the engine was there - what do I do now ???

Actually, it really made me mad, cause it's our first "nice" car, and we just bought it yesterday !!!

There were no other indications of anything wrong - the manual says it's emission system related - I'm guessing it's a marginal sensor, or something like that, but d@mn...

Anybody have any experience / clues - should I insist they take the car back ??? My wife loves it...

pcviewer

I am not sure about the location of the "box" for the 320, but I guess it would be the same as the 500/600. Looking straight into the engine bay, there is a "box" on the left top side (or passenger side nearest to the windsheild). In that box is a series of numbers and a button. Once you locate this, this is what you could do to get rid of the light:

Postion the key to "3".

Hold the button for eight or nine seconds (one or the other, seems time sensitive). If the led light maintains a second or two long flash, then the problem should be fixed. If it blinks, keep on trying.

To prevent the light from showing up ever again, do not drive the car hard and start the engine lightly (ignition bursts of < 1 second).

Pic of the engine bays:
http://www.geocities.com/pcviewer/box.htm

JunoJim

Thanks !!!

I was thinking, in other cars the check engine light is usually a trivial thing. We drove thru an area that was pretty smoky from burning underbrush - think that might have done it ???

Being an engineer, I can't wait to try your suggestion - I love to fix things myself...

pcviewer

Not sure to as how the light turns on. Someone else suggested that it has to do with smog equipment in this thread:

https://mbworld.org/forums/showthrea...threadid=31637

Whenever the engine check light is on, I don't notice any driving problems. I do think that starting the car wrong (holding the ignition for > 2 seconds) contributes heavily to the light turning on. That is only my experience though.

JunoJim

Well, I took a quick look, and can't find the box - will look some more tomorrow...

Seems like several marginal conditions can cause it - like not tightening the gas cap...

PS - I just looked at that other post, and we had just plugged in our cell phone charger too !!! Velly Intellesting...

pcviewer

The box isn't that big and is covered by a removable piece. If I have some time this weekend, I will see if I could take a better picture of the box with and without the cover. I will also have to verify the location of the box on the 600 as I have never actually accessed it.

JunoJim

Thanks - I'll look more closely - the dealer says they want to see it, so I'll at least look over his shoulder when he does this extremely difficult operation - LOL

The phrase "Idiot Light" comes to mind...

Anyway, I'm glad it's nothing serious - we love the car - I'll post a pic...

Well, I guess there is no "box" the dealer opened a cover, and there was a connector with ~ 30 contacts which he hooked up to a diagnostic read-out, that told him nothing was wrong - LOL I guess it reset the CEL at the same time, no recurrences...

Thanks - I'm glad I found this Forum, and plan to visit often !!!