I want to reset my ecu, start "fresh" and do the idle relearn procedure.

When you guys want to reset your ecu, is 12 hours enough to clear it or does it take atleast 24?

Appreciate any insight or tips, thanks!

I heard it takes 24 hours, but I also heard that you just need to disconnect the battery and turn your key to "On" and it should also do the trick.
But I haven't a clue, when it comes to electricity I'm lost.

Ive never heard of that key trick before!

I didn't think there is a quartz battery on the ECU anywhere, is there?

If you crack open the ecu and find one (looks like a big watch battery), you might be able to yank it for a few seconds and reset manually.
But this is just speculation, I don't really know for sure.

I dont even know where they tucked the ecu on my car

There are only four possible locations for ecus on Nissan AFAIK... Either behind the passenger side kick panel, behind the driver's side dash/kick panel, under either seat or in the center of the dash somewhere (most likely not you since you are ~RWD and thusly have have a trans tunnel).

that'd involve cracking everything open...

a few hours is all you need to do the relearn. I need to do a tuneup on the Civic...might do the relearn too, it's used to lax highway driving

Well I disconnected the battery at 9pm, so Im hoping by 12 noon lunch tomorrow (15hr) I can install my new MAF and t/b gasket and start her up

I just wanted the ecu to start from "scratch" so to say, since Ive done a few mods without ever changing anything, and now a K&N filter instead of a cheap cone, new MAF....

Im hoping it goes ok

go step on the break for awhile. it use all the last bits of power you got in the system.

Mine only takes like 15 minutes, but hey, its from 1991 and OBD I.

I've also heard you can disconnect both terminals from the battery, then touch them together. That should discharge everything, but I dunno about that theory.

I was told 15 minutes, then touch the terminals together to completely discharge the system is one procedure. But, I would check the FSM or call the dealer to be sure.

That's just to clear check engine codes. To do a full reset, it is something like 12 hours. I would look more into it though, as it varies on the vehicle.

touch the terminals together??

Really?

He means after the battery has been completely disconnected from both the red and black clamps, touch the clamps together.

Overnight should do the trick. 15 hours will do you just fine. After you disconnect the battery, turn your lights on to drain any residual power left in the system.

Dattebayo wrote:He means after the battery has been completely disconnected from both the red and black clamps, touch the clamps together.

I just thought that would be a bad thing, to basically ground your positive

I will def step on the brakes and see what happens since Im bored lol, santa aint here yet

CanuckQx4 wrote:I just thought that would be a bad thing, to basically ground your positive

There is no real polarity if the battery is disconnected.

im almost postive if you turn the adjuster screw on the ecu all the way to the right or left (i forget) it resets it. and the other way is diagnostic mod.

On mine, it stays all the way to the left. I've never heard anything about that.

brizanden wrote:im almost postive if you turn the adjuster screw on the ecu all the way to the right or left (i forget) it resets it. and the other way is diagnostic mod.

I checked some FSMs, and that works for ODB1 and 2, but you have to turn it all the way and then back twice.

Don't know about more modern then that...

well hopefully 16 hours is enogh and I will touch the terminals together and try the brakes and light test before installing my maf, then reconnect the battery and hope for the best

^just do the adjuster thing thats how a nissan tech told me to reset mine and it was an 1997 obd2 ecu,

i touch the terminals together thats the fastest way to reset the ecu.

even without touching the terminals together, reset only takes like a minute. The idea that it takes hours is preposterous. who told you this