Great forum for technical information.
I ran into a mechanic challenge for the experienced tech on my 1985, 500SEC Euro.

After reading a lot about checking for the the closed loop setting I purchased a recommended Sears multimeter to check the lambda settings and closed loop settings and discovered a small problem after the readings made no sense. The more I looked at #3 location I could see no metal female connector. So a popped off the plastic retainer and sure enough there was no pin connector in the #3 location. Even though a European car, it seems odd #3 is missing. Is there a color code on the pin wires I can defer in case there was a musical chairs on the pins? Pin #2 does appear to be a ground by resistance check.

The X11 connector on the left fender has no wire on the #3 terminal slot

I hope the attachment works as the missing #3 is visiable.

Thanks

Kurt

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Hi

I have a 92 Euro 200 and it doesn't have pin 3 too! Is pin 3 just an extension of the EHA connector? There must be a reason that they purposely left out pin 3 on Euro models.

Oreo

Yes, from Steve Brotherton's DIY, this is part of the EHA check for lambda or correct fuel to air ratio.

Kurt

The cars with an EHA are KE-Jetronic. US cars in 1985 (except 190s) are K-Jet w/lambda. Euro models are plain K-jet. They don't have lambda control except as added for EPA compliance (and possibly a few catalyst cars - rare). The modifications if they still exist will vary and very likely won't use the factory diagnostics.

Mixture will have to be adjusted with an exhaust gas analyzer if there is no O2 sensor.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

The Euro car has both an O2 sensor and Catalytic exhaust. It recently passed emmison tests fine but fuel milage is low at about 15 mpg for freeway.

With an O2 sensor is there a way to check for lambda even though no #3 on the X11.

Kurt

Can the lambda be checked using the frequency value just as well as the EHA?
My frequency valve was added as part of conversion from a Euro model as well as the O2 sensor.

Kurt