trevorgetty

Correct it does fluctuate 
the reading of 0.44v is actually given out by the ecu itself when in an open loop state.  Effectively during startup before the o2 sensor is up to temp which is something like 500degrees the ecu has to perform in open loop mode.  Otherwise it couldnt use other sensors as they would be invalid.  Its like the old automatic choke in old cars.   My problem is that when it gets up to temp it should come out of open loop and start using the real values from o2 sensor etc.  Any one know the list of items that dictate open loop in the mems1.6 ecu?  Im assuming coolant temp, o2 sensor temp are there any others?  I want to rule them out one by one.   Im gonna swap loom over to test as i think there maybe a strange earth issue.  What i mean is that when starting the car it nearly always starts the car fan. Just as if the car was too hot or the coolant sensor was unplugged after 30s it turns off and works as normal with engine temp turning it on and off.  Unplugging the sensor also turns fan on.  So I'm assuming some fluctuation during startup...  if anyone has any ideas would be appreciated but im assuming some in depth knowledge here or something that has had same issue.