I BELIEVE that you disconnect the battery for about 5 minutes, hook it back up, than let the start the car and let it idle for about 5 minutes. Pretty sure this is it, but someone will correct me if I'm wrong
I did this when I first heard about it, it seemed to very slightly clean up my idle. I may have just imagined it though.
I did it again after I had installed my short ram intake, just to make sure that it woudl recognize the difference.
i've heard that you should wait closer to 20-30 minutes. i always disconnect it and hit the brake pedal a couple of times to speed things up. you're basically just waiting for whatever reserve capacity is in the system to die out so that the ECU will completely reset itself.
PS- watch out for that damn alarm! sometimes it likes to go off when you hook it back up. i've found leaving the alarm in valet mode eliminates that, though.
Who here on this forum knows the ECU/PCM/ECM component intimately ?
I would like to know why you need to disconnect the power from the ECU/PCM/ECM for 15 to 20 minutes for it to lose it's memory/settings.
Does it have a temporary backup battery(capacitor) that keeps it's charge for 15-20 minutes to perserve the ECU/PCM/ECM settings during a normal battery change ?
i have a 2000 ford focus not getting an o2 sensor, catalytic converter and other readings from the ecm. i had ity replaced with a used one at the ford dealer have the same problem was wondering if there is a fuse or relay and could that might be the problem