How to reset Check Engine indicator lamp
#1
![Question](https://mbworld.org/forums/images/icons/icon5.gif)
I just replaced the missing o2 sensor in my 1986 300E, but the Check Engine lamp still comes on (and stays on) after the ignition key is placed in the ACC position, and won't extinguish even after the engine is started. I'm guessing the error that was stored due to the missing o2 sensor still causes the lamp to stay on and needs to be cleared.
Can anyone tell what the procedure would be? I'm very electronics literate so don't worry about getting technical with this one. Thanks.
-Alex
Can anyone tell what the procedure would be? I'm very electronics literate so don't worry about getting technical with this one. Thanks.
-Alex
#3
RE: "missing o2 sensor "
Uh yeah, you're on the tight track friend. Solving to reset the lamp is fine but the sensor has a major roll in your fuel mixture. I thinking you need to restore the sensor as your fuel ECU mapping may be off the charts. Like too lean or rich. Not good, could damage the engine.
Solve for the sensor and get a bonus - the check engine will remain off properly.
Uh yeah, you're on the tight track friend. Solving to reset the lamp is fine but the sensor has a major roll in your fuel mixture. I thinking you need to restore the sensor as your fuel ECU mapping may be off the charts. Like too lean or rich. Not good, could damage the engine.
Solve for the sensor and get a bonus - the check engine will remain off properly.
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
#4
MBWorld Fanatic!
If
the problem was fixed the light would clear itself,it can remain stored for several drive cycles, but if solved would not show the check engine light.
So back to the drawing board,read the codes,post them,solve the problem and the light will go out.
ohlord![bow](https://mbworld.org/forums/images/smilies/bowdown.gif)
"GOT CODES?"
So back to the drawing board,read the codes,post them,solve the problem and the light will go out.
ohlord
![bow](https://mbworld.org/forums/images/smilies/bowdown.gif)
"GOT CODES?"