Reset Ecu

[mkasap]

hey guys,

i got fuel economy problems as well. i do about 200 km a tank normal driving. i bought the o2 sensor, now when i change it, do i have to reset the computer and if so how can i do it?

thanks,

[__PhaseShiftDown]

you shouldn't have it.

just replace it and see if you notice any improvement. You can reset the ECU if you want.. just to be safe.

[zerotohundred]

hey marko.

looks like ur a new member welcome to skylines australia

ok now you need to reset the ecu if u change the o2 sensor. to reset ecu just disconnect the battery and let leave it for a couple of minutes to discharge. you cud press down on the brake as well to discharge whatever is left. once done reconnect you battery and away you go

Edited May 28, 2009 by zerotohundred

[Benzino33]

hey marko.

looks like ur a new member welcome to skylines australia

ok now you need to reset the ecu if u change the o2 sensor. to reset ecu just disconnect the battery and let leave it for a couple of minutes to discharge. you cud press down on the brake as well to discharge whatever is left. once done reconnect you battery and away you go

^^ what he said

[R 2 THE J]

Pffft...I still can't believe you guys would go into so much trouble to reset the ECU.

The proper way to do it according to a NISSAN ECR33 Service Manual is this.

1.On the right hand side just under your steering wheel is a fuse box cover. Pull it off. You will see a set of fuses and some Wiring Looms.

The one we'll need looks like this, it is not connected to anything, this is your diagnostic plug that NISSAN uses to find faults.

2.Now grab a piece of wire, bout .5mm-1mm in diameter, you need atleast 10cm and splice the two ends off like this.

3.Now we're going to short out 2 (two) of these pins, which will reset the ECU in this process.

-Turn the Ignition onto "ON", within the next 10 seconds you need to...

-Place one end of the wire into the Bottom Left Pin. "YES" put it in there...you won't get a shock.

-Place the other end of the wire in the Pin right next to it....

LIKE THIS

Your engine light should Flash 5 (five) times SLOW and 5 (five) times FAST.

CONGRATS...ECU RESET!!!!

It does sound complicated, but it is EASY AS!

Any questions..feel free to ask!

Also, you will need to go for a spirited drive for the ECU to correct AFR's. Atleast 3 to 4 0-100km/h runs.

Fuel is not changed, as it uses standard fuel map, but rather adjusts the Air coming in.

It will fine tune itself over a period of days.

[mkasap]

hello again!

i swapped the o2 sensor over the weekend as well as the full service was done on the car. took it yesterday for easy drive around, i used almost half of the fuel tank and done 190 kms which is much more than what i did before this!

only cost me $109 for the NGK o2 sensor from Autobarn!!!

Thanks for the help gentlemen!!!

cheers

[Wacky Dee]

so umm .. changing the o2 sensor without resetting ECU would not do much good eh ? Because I have a remapped ECU with a special daughterboard installed ... would resetting the ECU make me lose my tune ie. AFRs and timing set by the tuner, when the ecu was remapped ??

[Moodles2]

so umm .. changing the o2 sensor without resetting ECU would not do much good eh ? Because I have a remapped ECU with a special daughterboard installed ... would resetting the ECU make me lose my tune ie. AFRs and timing set by the tuner, when the ecu was remapped ??

Tune is stored in read only memory, no way to undo it unless you pull the ECU apart and physically rip that chip out

[Benzino33]

Tune is stored in read only memory, no way to undo it unless you pull the ECU apart and physically rip that chip out

Oh cool, Good thing i read this before i started a new topic. I got a tuned ecu and wanna reset it before i run it in my car. Will give it it a go tonight.

Cheers

Edited June 3, 2009 by Benzino33

[Wacky Dee]

does anyone know if the instructions posted above by "R 2 THE J" also apply for R34 GTT and if not, does anyone know how to do it in an R34 GTT ? Cheers

[mad082]

pretty sure they are the same. the very best way to do it is to buy a consult cable and reset it that way. it actually costs money to do but gives you a valuable piece of equipment that allows you to also monitor things like the AFM o2 sensor, etc as well as read fault codes without having to count a flashing light

[Moodles2]

^^

+1 ecutalk.com sells usb consult for about $75 iirc, definitely a good investment

[Wacky Dee]

any free software that works with the usb consult cable ?? I'm thinking of getting a Nisture chip down the road so I might just get this usb consult from http://www.plmsdevelopments.com They sell the Nistune software too but right now I don't need it as I'm not getting the car retuned just yet..

[Moodles2]

http://ecutalk.com/ecutalk.aspx

http://techdiag.co.uk/obdscantech/web/pg002.html

http://www.calumsult.com/calumsu/CalumSult/

http://www.300zx-twinturbo.com/conzult/downloads.htm

http://eccs.hybridka.com/viewtopic.php?t=263

and for those mac users out there: http://members.cox.net/epooch/

[Wacky Dee]

thanks mate

[NewKleer]

CONGRATS...ECU RESET!!!!

Any questions..feel free to ask!

the only question i have is "are you sure". i know what you've described is how you get the fault codes, but ive never heard it resets the learned parameters in the ECU? where did you read that? (i guess i should look in the service manual myself).

[Birds]

This ECU resetting logic is a bit askew in my opinion...

Why are we resetting the ECU? It doesn't store an infinite amount of driving patterns - with most ECUs the existing patterns should be overlapped after about 30 ignition starts anyway. It's certainly not necessary for installing a new oxygen sensor. My car is evidence of this; economy went from 250km per 50 litres to about 380 after installing my new sensor. Are we also assuming that the new oxygen sensor is not going to send voltage readings of its own, and that the ECU is infact going to reference the old sensor's readings instead? Kind of defeats the point of having an oxygen sensor in the first place don't you think!

Also, after resetting the ECU, full throttle 0-100km/h runs will in no way be beneficial - your standard driving style will overtake this in about 30 ignition starts anyway.

The only time I would reset an ECU is to clear fault codes or if I had idle troubles which the ECU can maintain even after driving pattern overlap. All this said, whenever I am working on engine bay wiring I disconnect the battery (which will automatically reset the ECU after 20 minutes anyway). However, oxygen sensor is just plug and play installation so you will be safe from electric shock.

[Wacky Dee]

Pffft...I still can't believe you guys would go into so much trouble to reset the ECU.

The proper way to do it according to a NISSAN ECR33 Service Manual is this.

Oh the irony ..how's doing ALL THAT less trouble than disconnecting the battery for a few mins ? Heh.

Anyway, changed my o2 sensor with a genuine Nissan one and got zero improvement. Changed the AFM too. I must be the only person on SAU who's had ZERO improvement after changing the o2 sensor. I do have a JJR dump pipe ..could that have something to do with it? Maybe the o2 sensor just isn't able to give correct readings? I read somewhere before that some people had problems with the JJR dump pipe..

[NewKleer]

dont forget u have a remap...maybe that has messed up ur economy.

was ur o2 sensor dead before? does it work now? otherwise u may have just replaced a good one with a good one?

[Wacky Dee]

economy hadn't changed after remap ..plus the remap made the AFRs leaner as it was running rich from factory as they all do, so you'd expect that would have given me a better economy on its own but nup..

The factory o2 sensor was not dead but it was time to replace it anyway. Just surprised neither new o2 sensor nor AFM made any difference, that's all.