Resetting ECU

Im just about to reset my ecu, whats the best way to do it?

D/C the batterry terminals in the boot? or can I just pop the hood and disconnect the terminals there?

Thanks.

ex

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just disconnect the ones in the boot, then you can either tap the brake pedal a few times or you can leave it over a 24 hour period

24hour period?

i just leave the door open (with light on) dc the battery and it drains itself, take like 2 seconds

i've heard different stories, the main aim basically is to drain any remaining power in the car's system

Leave it over night......i have also heard that to properly reset the ECU you need a proper diagnostic tool.

The proper diagnostic tool is a wire paper clip
The R33 method is to open the fuse pannel under the dash
you will see a grey connector pointing downwards, pick the two wires on their own in the plug (the ones closesed to you) turn on the ign put the paper clip in so it shorts the two wires for around two seconds (this puts the ecu in diag mode) remove paper clip.
the chk eng light on the dash will start flashing a set of codes turn the ign off & on again the ecu is now reset
benifits: no reprograming the radio or clock & no spanners sparking on the rear of the parcel shelf (killing the ecu's).

Regards DAMQIK

That sounds _very_ dodgey although it's probably right. I've been told that the ECU has a built in battery (button type) that even after disconnecting the battery will retain the ECU setup. So the only way is to flatten/remove that button battery or to short the ECU as described above. DAMQIK can you explain what the wires are and how it works?

hehe, dodgy but effective eh? The diagnostic tool for the skylines is damn expensive, lucky my mechanic mates got one!

Yes, one wire is an earth and the other a signal (to put the ecu in diags mode)
it dose the same as removing the passanger kick trim ,unbolting the ecu, turning it around and turning the little knob arround clockwise all the way with a fine screwdriver.

which BTW may be easyer if you are unsure about using a paper clip.

DAMQIK

im too scared to do the paper clip one as i know what will end up happening... i'll electrocute myself! :D

now is it the same for R32/33 or are they diff?

***EDIT

also... once u turned the nob or whatever around do u have to turn it back and then bolt it back on?

The r32 only has the knob I dont think it has a plug for a paper clip to go into.
the knob needs to be in the diag position for the whole time you need it to show fault code's
remember to turn off ign before setting the knob back into its original position.

DAMQIK

I reset my ecu last night..

works well..

using the paperclip method?

Nope, I d/c'd the battery.. stomped on the brake a few times.. reconnected the battery, took her down the road until I hit the speed limiter.. 3 times

I thought that should do the trick

I was just hoping it didnt reset my safc settings.. doesnt seem to have

but wouldn't it 'learn' the new A/F ratio and counter-adjust the safc settings to bring the AF ratio back to factory settings?

I really don't think it would have done too much.....the proper diagnostic tool is needed and after the reset there are certain driving processes it needs to help the computer 'learn'.

well it seems little more resposnive, nothing fantastic.. and nothing to rave about.. but we'll see in due time.

i'll wait for the next dyno day to get my safc tuned again.