I purchased a used 2002 C230K Sport Coupe recently. After driving it for two weeks, the Service Engine light began glowing on startup. At the same time, I noticed that the engine would surge slightly, speeeding up and down in a rhythm when driving at a steady rate, either with or without the speed control engaged.

I installed new correct plugs and changed the air filter, but the problem persists. I also feel the gas mileage is lower than I would expect, getting a steady 25 mpg on my 100 mile roundtrip commute on highway (70 mph) and some open two-lanes (12 miles at 60 mph)

Is there a way to reset the Service Light without going to the dealer or a shop, such as disconnecting the battery for a time? How abut the mileage? Thanks for any asistance you folks can supply.

Richard

OBDII scanner will do it if the fault is engine related. Wont if it is trans or other module.

Why not find out what the fault is and fix it though?

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Scan it and see what the codes are.

Or you can pull the bulb and ghetto rig it.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I would be more than happy to determine what problem caused the light to come on, but here in CA, the autoparts stores may not read the code for you. And I'm sure the dealer will charge the minimum 1 hour charge to read it. Does anyone in the Central Valley or Bay Area have a reader I can borrow or rent?

Autozone should do it for free, if not have the dealer do it. You own a Mercedes ya gotta pay to play.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It only costs about $50 to play that game. Get a scanner. Once you've got one you wont ever need it again....cheap insurance.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

The check engine light is SUPPOSED to light on startup. That's the bulb check.

If it remains on, then you have a problem.

You can't just turn the light offf, you have to fix the problem.

The light is indication the car's computer has "stored a code" describing generally what the problem is.

You can get a code reader to see for yourself, but the reader doesn't fix the problem.

Government emissions testing involves this same reading of codes, and if there are any, you fail.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles