mbarrad

I have a stock 2003 C230 SS with approx 33,000 miles. I got a CEL this afternoon out of the blue upon starting the car. Has anyone ever experienced a CEL at such an early point in an M271 engine? There are some CEL threads, but none could really pinpoint what might have caused the light to come on. The car Runs fine performance wise with no strange noises or overheating. The only real performance mod I have is the Sprintbooster which I doubt could cause any engine problems that would set off a CEL. I heard that Autozone can run a free diagnostic through the ODBII port to see what the code means. I doubt it is the O2 sensors, but I could be wrong. Any common things I should look at before taking it to the dealership? I want to pull some codes before removing the Sprintbooster, but I don't want to go too far without knowing what happened.

mbarrad

Update: I went to Autozone and they do have a free ODBII scan service. They hooked up their unit but was unable to establish a link. Anyone ever have that happen? What is a good brand or model to get because I might buy one soon. I was bummed because they could not find a code that set the CEL off. By him hooking up the scanner, it reset the CEL so I am fine for now. Wish I could have gotten that error code.

Buellwinkle

MB's OBD2 port is picky, not all scanners work with it. I use software from OBD-2.com and it's worked on every single car I've used it on and not only that, they have C class specific codes that may pinpoint the problem better. It may help to include your city in your profile so you can receive more localized help like a better place to go or borrow someone's scanner.

Also, there's hundreds of possible codes, don't worry about what maybe wrong. Could be something stupid like a loose gas cap.

Vivid

I have the OBDII software and it is a time saver. I used to use it on my other cars. I have not needed it yet on my c240.

slammedcclass

If u think that is too soon for a check Engine light cuz my car was 900 miles and i was driving and i was very close to the mercedes dealer. i just got off the free way and it was a red light so i stopped and my car started shaking like crazy the engine was going crazy so crazy that i got scared and then it turned off i was the first on the light and all the people behind me were going crazy cuz i was not going cuz i guess they did not expect a new car to just stop like that. So i tried starting the engine i turned it on drove to the dealer when i got there it did the same thing i scared like all of the people and then it turned off and i had the engine light and every thing the people that work were tryin to talk to me cuz i was about to trade the car in
Lol
and the funny part when the guy came and said let me see whats wrong opened the hood turned on the engine and he went to see whats wrong and the engine went crazy and he ran inside the car and turned it off and hes like okay i get it Lol

bnzct

I had the same problem: they use an older scanner at Autozone. What you need is a "CAN" capable OBDII. There is a cheap one (about $60) at Wal-Mart that works fine on our car.

mbarrad

I'll look at Walmart for the scanner. I am also going to look into the ODBII software. Thanks guys!

AnnHo

that's funny because my car has about 30k miles on it also and the check engine light came on unexpectedly. Well it was friday afternoon already so I couldn't take my car to the dealership. My boyfriend suggested the free diagnostic at autozone so we went there and the guy said something about the sensor also. Well when they unhooked that scanner, the check engine light disappeared. One week later, the CEL came back on so I called the dealership and my service advisor said to not bring your car to autozone because they don't usually have the correct equipment for our cars. The dealership found out that it had something to do with a leak in the vent hose or something and they had to have that replaced. andddd since my car was at 30k miles they had to do some decarbonizing thing that cost me $230.

Just thought I would let you know.... I had the same exact problem as you. My car is fine now, though... *knock on wood*

mbarrad

The light came back on yesterday and just went out by itself this afternoon. Wierd

If your 05 C230 had a leaky vent hose, shouldn't they replace it under warranty at no cost?

amdeutsch

That was probably free, but the cleaner they dumped into her gastank wasn't. She got took IMHO.

robohopar

Yeah...i'm totally stock also...and i got the CEL light like at 25k miles...on and off though...never got to check it but now i have 34k miles and its on and been on for a while now...ill go check it out soon...ill post my DTC and we can all discuss what our M271 malfunctions on lol

AnnHo

Yeah it was replaced with no cost. The decarbonizing was totally different. They just said that it's usually recommended to do some decarbonizing at 30k miles. but the vent hose was replaced.