What is definition of ECM open loop? Is it open on all sensors at once or just some? are there any sensors that it reads all the time?If bad ECM ,would it act like open loop? I have an 89 350tpi with idling problems ,stays at 1200-1500rpm all the time.Would a bad ECM do this? also the driver side fan runs all the time ,even on cold start up. and relay on firewall in front of driver clicking rapidly when turned "on" (replaced, no change) .Have changed IAC and Coolant temp sensor, no help. Checked grounds and disconnected battery to reset ECM and checked for vacuum leaks. Readings from ALDL using jumper are 12 , 11 with clicking, 12 , 11 with clicking then erratic blinks that make no sense. Any thoughts guys ?

 

As far as our cars are concerned, code 11 doesn't exist. As for open loop operation, this is easier (and many less typo's) then me typing it out...

 

Deadbird , thanks for the info. I gotta absorb this and see how it applies. Gonna check out your site too!