Oxygen Sensor wire to CIS Unit Repair - PeachParts Mercedes-Benz Forum

JamesDean · #6 05-24-2009, 04:55 PM

Quote:

Originally Posted by slk230red

The easy way to check the O2 control lead is to ground it and see if the EHA current goes negative. Or, take a 1.5v D or C battery, negative side to ground, touch the control lead to the positive side and the EHA current should go up. You can tell either way by how the engine idle changes.

By the way, are you putting your CFI Module in Diagnostic Mode to check the duty cycle?

Hm... I'll have to try that trick you said because, as per the FSM, I got no continuity between the o2 control wire and any of the pins on the cise connector. I even checked with a known working car (90' 300SE) and none of its pins are connected to the o2 sensor.

I dont believe that i have to put it into diagnostic mode for duty cycle. A friend of mine who was helping me adjust it said that I didnt need to. Also, it was reading duty cycle numbers fine prior to something causing it to go to .09v=100% dc. I just checked my friend 300SE and it reads duty cycle fine.