Hi there,
I just installed the Civic security system in a 2005 hybrid (be careful when pushing that white-wire pin into the green connector-- make sure it's the right slot!).
Anyway, you have to disconnect the negative lead off the battery, then when done reconnect and you need to perform an "ECU idle learn" procedure. Basically run the engine at 3000rpm with all electrical accesories off , when the engine fan comes on let the car idle for total of 5 minutes. I did this (well in excess of 5 minutes BTW). Now I get the feeling that my mileage has dropped. I need to get more miles driven to verify, but does anyone know about this ECU learn thing? Could this cause a mileage drop? If so, what do I do?
Thanks for any input

Peter

What is this ECU idle learn thing? Normaly the idle learn is for an alarm with remote start. I've never heard of the ECU idle learn unless the ECU you are talking about is the alarm brain.

Is it a honda security system or aftermarket and if aftermarket what model?

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"

All cars from about 1985 onward use an O2 sensor to continually richen and lean the fuel mixture for optimum efficiency. There's no reason to let it sit and idle since the fuel trim is updated continuously during all driving conditions except when the pedal is floored.

I installed the security system as well. The instructions I read online mentioned the ECU idle precedure. However, the instructions I received with the unit looked exactly the same, but omitted that section. Consequently, I did not do the ECU procedure and suffered no ill effects. Hope this helps.

Clay

Thanks for all of the responses. I think I should have waited, since I'm back up to my usual 48-50mpg on my commute from CT to NYC. Again, we've been having some real hot days and I try to keep the AC off, but eventually I can't take it and turn it on.
Oh, the security system is the factory Honda unit. I got it from Honda Bloomfield ("hondaking143", on eBay for $125. Never a problem dealing with this dealer.

Thaanks again.

Peter

Just don't do it. You can drive without doing that if you don't mind not to have assist at all for 5 min drive... I did it twice no problem at all - no drop in mpg at all because you move. If you sit and run the engine you don't do any mpg you just do minutespg