I have been reading almost all the posts on OVP,O2sensor,EHA
but i have not yet figured out my problem.
My values:
duty-cycle on pin 3, 35% when engine is hot,28% if i push the plate.
02sensor measured output voltage 0.9v when green wire shorted.
O2sensor heater current only 0,45Amps.
3.6 volts on pin 3 whith engine off ingition on.
The coolant sensors have only 5 ohm difference.(compared to each other.)
I have checked the fuses on the OVP - OK!
OVP was labeled SIEMENS (dual fuses)

Problem:
EHA current 0 amps ,not even a microamp.

Pelle ,300E 4M -89