Idle relearn procedure

[honda]

I've read two different ecu reset/idle relearn procedures described. They have both been described as the "correct" way to 'reset' the idle after resetting the ECU.

The first way is described as:

Drive the car to get it warm
Remove the ecu and clock fuses
Wait 15 minutes
Put the fuses back in
With all electrical components off, restart the car, but don't rev it or anything, and let it idle for 15 minutes
Turn the car off
Turn the car back on
Drive the car for 15 minutes

The second way is described as:

Remove the ECU and clock fuses
Wait a minute and put the fuses back in
With all electrical components off, start the car and rev it at 3000 rpm until the radiator fan comes back on
Then let the car idle for 5 minutes

I tried both ways, but I don't think I could hear the radiator fan come on for the second way. I revved it to 3000 rpm for maybe several minutes, but I don't think the fan came on.

Does anyone know how long you have to rev it at 3000 rpm (I have a Honda Civic 1997) to get the radiator fan to come on? I know when I just let the car idle on its own (with no revving), it took about 11 minutes for the radiator fan to come on.

Does anyone have any experience with these two ways of resetting the ecu/idle? Is one way more "correct" than the other, or what is the difference really?

[Oldblueaccord]

Well first off this site is for 3 generation Accords so the Civic knowledge may be limited.

As far as an idle relearn I never heard of any of the procedures you listed above. I would think just resetting the ECU would be enough plus some driving.

I know if the ECU is reset on my car I have to drive it about 25 miles before the hot idle will pick up or it just dies.

[honda]

I think civics and accords are probably similar enough that the idle/ecu reset procedure is about the same. If anyone has read different ecu/idle reset procedures for accords, I'd be interested to know what they are. But interesting about the 25 miles.

[Jafir]

I think civics and accords are probably similar enough that the idle/ecu reset procedure is about the same. If anyone has read different ecu/idle reset procedures for accords, I'd be interested to know what they are. But interesting about the 25 miles.

Most newer old Hondas, with an iacv, the procedure to set idle is to disconnect it the iacv, set the base idle to whatever the spec is (about 500 rpm I think is common) and then plug it back in and clear codes. Does your 97 civic have an idle adjusting screw? I had a 1998 once, but I don't ever recall having to adjust the idle. I think I've got a PDF of the factory service manual on my computer at home though. In can look it up in a couple of days.

[2oodoor]

I don't think holding a car at 3000 rpm sounds like a factory advised technique. Basically getting it warmed up and the cats clear for "settled" O2 readings should do, hence the 25 miles...8 miles should suffice one would think though. Getting the ECU to leave the timing alone is one thing that has to happen too, unplugging the iacv does make sense mechanically but the ECU needs to not compensate the idle speed with the timing. Really It all depends what generation engine management you're dealing with.

[Jafir]

Right. On some of them there is a jumper in the right kick panel that keeps the timing static so you can adjust the timing at the distributor.