I just digested all the KE3-Jetronic System from landiss.com as it pertains to my 1989 560 SEC's.

I did the lambda on/off duty cycle ratio test at the X11 diagnostic connector between pin 2 and pin 3 with with ignition on and engine off I established
I have the "California Connector".

If I understood Dan@landiss the Calif car cannot perform the lambda on/off ratio duty cycle test, at least not at diagnostic connector X11.

As for diagnostic connector X92, I can get the LED light to either stay constant on or constant off.
I cannot get LED to flash.

Is there a multi-meter test to determine the status of the oxygen sensor??

Thank you for your time and consideration.
mitch mabee
mitchmabee99@Gmail.com

1989 560 SEC