Need to reset O2 sensor dash light
 

Just replaced my O2 sensor, but I do not know how to reset the
dash light. Searched previous posts and could only find reference to disconnecting battery. Tried it - did not work.
'93 190e 2.3
Can anyone help me out?
:confused:

Could be that the dash light is indicating another problem. Is yours a model with a button and LED in a (X11) connector along the firewall? If so, set the key to #2 position (just before the starter engages), press the button for 2 seconds, then count flashes. Press the button for another 2 seconds and check for other codes. The codes will repeat in ascending sequence.

Sixto
95 S420
87 300SDL

Sixto-
Thanks for responding-
I believe that I found the test connection (X11/4 - impulse readout, 8-pole). Am I correct?
Held button in for 2 seconds and received 1 flash.
LED was on when I turned key to #2 position. After I held it in for 2 seconds, it did go out and then the 1 flash.
If I press the button again - the LED stays on.
-John

That goes beyond what I know of the early OBD. I'm pretty sure the light should never stay on and shouldn't come on until you hold the button for two seconds. I believe one flash means the ECU is fine.

Try getting Steve B or Donnie in on the thread.

Sixto
95 S420
87 300SDL

On the later model W201's there's a reset button located under the carpet on the passenger side. Have a look for a square box with a button on the top. Hold the button for at least 2 seconds. The light will only go out after the engine is started.

I just did the O2 sensor on my w202 yesterday, and to clear the CE light I just disconnected the battery. Will that work on your 201?

Jonathan

Checked under the carpet on passenger side. Can only locate the cruise control amplifier, SRS voltage converter, anti-theft alarm control and X11/13 which is the SRS test connection.
No box with a button.
I disconnected the battery again but no luck.
The red LED does go on (X11/4) every time I turn the key to the #2 position. If I press the button for 2 seconds it will go out, but will light up again when the key is turned to #2 position.:confused: