Reset ECU

[Blitzen]

I've searched and search, but there dosen't seem to be a thread about resetting the ECU on Accord Euros

I drive a '03 Euro, only replaced the panel air filter to the one offered from K&N, and I believe the engine is running rich. Honestly I don't VTEC the engine at all thesedays, and I've been easy on the throttle ever since, I change gears at around 2500 and short shift where ever I can and only fill up half a tank. Best I could do is probably 200km to 220km and all on city driving...

My mate notices I drag high gears to keep driving at low rpms, knowing it's wrong now and I've changed my style, but still not much of an improvement to fuel consumption, so I was wondering could it be the air filter creating wrong readings to the sensors and in turn increased fuel consumption directed by the ECU?

I've been reading Integra drivers could reset their ECU by disconnecting the battery and reconnecting after certain time, can this be applied to Accord Euro's as well?


Thanks

[Type R Positive]

I just disconnect battery for a few minutes.

[beeza]

Yes it can.

Remove the ECU fuse in the fuse box in the engine bay.It's the BIG one and it's 80A (amp).
Leave it out for 5-7 minutes (a good 5 minutes)
put it back in and start the car
don't touch anything!
let it idle for 5-7 minutes
turn it off
turn it back on and your done.

[aaronng]

Or just take the negative terminal off.

Have you checked your tyre pressure?

[integral90]

Is it possible your ecu could just be getting lazy from driving it so soft and it has to work harder to go the same speed now?

Have you tried just driving it hard for a day or 2 and seeing the difference? I know I redline every 5th or 6th take off from the lights and go WOT pretty regularly and I still manage 500-525km out of a tank on city streets

[Blitzen]

I check my tyre pressure everytime I fill up, always at 34 psi front, 33 psi rear, considering to change the oil and fuel filters now

though I've been reading this thread http://www.ozhonda.com/forum/showthread.php?t=102189&highlight=reset+ECU

one member saids "taking out battery does nothing to the computer... Euro is all EPROM memory... it doesnt self reset!"


comments?...

[migoreng]

Is it possible your ecu could just be getting lazy from driving it so soft and it has to work harder to go the same speed now?

Have you tried just driving it hard for a day or 2 and seeing the difference? I know I redline every 5th or 6th take off from the lights and go WOT pretty regularly and I still manage 500-525km out of a tank on city streets

really? can an ecu get lazy?
maybe it's just my mind but some days i rev the engine and it feels fast and other days it seems slightly slower.
lol

just dc the neg terminal for like 20mins to reset everything

[integral90]

really? can an ecu get lazy?
maybe it's just my mind but some days i rev the engine and it feels fast and other days it seems slightly slower.
lol

just dc the neg terminal for like 20mins to reset everything

From what I've heard an ecu can kind of retune itself for fuel efficiency depending how you drive it. Maybe from driving so softly something in the engine isn't firing properly?

Also reply to the PM Blitzen!

[MiSloVic]

try to fill up a full tank instead. You will get a more accurate indication of how much fuel in your tank. Take the reading over 3 to 5 tanks. Using the same fuel. Driving too slowly, you are spending more time accelerating. I find accelerating briskly can actually be more economical.

[tony1234]

I check my tyre pressure everytime I fill up, always at 34 psi front, 33 psi rear, considering to change the oil and fuel filters now

though I've been reading this thread http://www.ozhonda.com/forum/showthread.php?t=102189&highlight=reset+ECU

one member saids "taking out battery does nothing to the computer... Euro is all EPROM memory... it doesnt self reset!"


comments?...
I'd put in 38 front,36 rear and see how you go.also oil and filter change will help depending when you last did it!Also a bit of enthusiastic sports driving,eg vtec it a number of times and it'll"wake up" the ECU.

[aaronng]

try to fill up a full tank instead. You will get a more accurate indication of how much fuel in your tank. Take the reading over 3 to 5 tanks. Using the same fuel. Driving too slowly, you are spending more time accelerating. I find accelerating briskly can actually be more economical.

Agreed, we can only compare if you get accurate L/100km numbers and not kms per tank.

[Suntzu]

Meh. Ive done heaps of changes. I also have the jutune. Forget about resting the ecu. Drive it for about 100kms hard. That will sort it.

Noticed a change like this when i did header, intake and especially hi flow cat. It alsways took about an hours of driving for it to "kick in". i dont think a filter will do a lot though.
Drive!

[Crapdaz]

What size wheels are you running? And are you doing alot of short trips or 30+mins of driving each day?

If your on 18 then go 36-40 F and 36-38 R depending how stiff you like it.
If stockies stick with around 34-36. <-- i htink you were running the 17" euro sports.

After you reset, drive hard for a day and it should do it well as the ECU adjusts to the better airflow quicker.

Note: Just a drop in filter shouldn't have too much affect on it but will still increase the fuel consumption by a tad.

Half tank gets used up pretty easily, i think the tank size is smaller when you get closer to empty.

[Suntzu]

BTW i get WAY better fuel consumption from my car and i rev its **** of daily. that being said you L/100 is vague and useless.

remeber:

Fill it.
Drive it.
Record KM.
Fill it again.
Divide the numbers for accurate L/100km

[Blitzen]

I wouldn't say I use the Euro that much, they would only be short trips, quite usual now to survive on $30 petrol for two weeks! and I always try to cruise at lowest possible engine speed, around 1500rpm, but that was before, nowdays I cruise at 2000rpm, and drop a gear for small hills rather than push the throttle a bit harder...

and I've just read an article from Motor magazine to support my point: "dragging intake past that almost-shut butterfly (cruising at low rpm) creates a partial vacuum in the intake tract and the engine has to work to overcome this vacuum and drag the atmosphere into it's lungs, resulting in partial cylinder fill and therefore lower efficiency" ('Variable Cylinder Management' by David Morley, Motor, October 2008)

I'm going to give it a go and reset the ECU by disconnecting the negative terminal for a good few minutes, though my mate just asked what about the alarm?...

[beeza]

My alarm has a key for it on the siren.I just turn that off.

[Crapdaz]

don't worry if anything happened to the alarm then it would have been posted on the forum.

If you have the aftermarket alarm then it might be a problem unless it has it's own power source.

Yeh give it a go, more short trips kills not only your engine and battery but fuel as well cause it doesn't give enough time for your engine components to warm up incl of any engine lubricants e.g engine oil etc.


I wouldn't say I use the Euro that much, they would only be short trips, quite usual now to survive on $30 petrol for two weeks! and I always try to cruise at lowest possible engine speed, around 1500rpm, but that was before, nowdays I cruise at 2000rpm, and drop a gear for small hills rather than push the throttle a bit harder...

and I've just read an article from Motor magazine to support my point: "dragging intake past that almost-shut butterfly (cruising at low rpm) creates a partial vacuum in the intake tract and the engine has to work to overcome this vacuum and drag the atmosphere into it's lungs, resulting in partial cylinder fill and therefore lower efficiency" ('Variable Cylinder Management' by David Morley, Motor, October 2008)

I'm going to give it a go and reset the ECU by disconnecting the negative terminal for a good few minutes, though my mate just asked what about the alarm?...

[aaronng]

Euro's alarm won't go off if you have a stock Euro. The only thing you'll lose are your radio stations and audio settings. If your auto power window stops working properly, just reset it through the power window switches.

[Blitzen]

yeah thanks fellers, will update progress

sorry breeza... great detail of resetting the ECU, but I'm not good with fuses so I'll have to go with the negative terminal way

I'll leave it disconnected while I give the car a good 1/2 hr wash, then reconnect and let it idle for a while?

[beeza]

No probs mate.

It is easy as :)

[aaronng]

yeah thanks fellers, will update progress

sorry breeza... great detail of resetting the ECU, but I'm not good with fuses so I'll have to go with the negative terminal way

I'll leave it disconnected while I give the car a good 1/2 hr wash, then reconnect and let it idle for a while?

You don't need to let it idle.

[Blitzen]

actually I'll go with the fuse way instead, can't find plastic gloves around the house...

so... I can't seem to find the 80A fuse that Breeza said, but I found one labelled 100A with a battery logo, and one illustrated as a engine and labelled FI ECU in the manual, which one should I take out...

[aaronng]

actually I'll go with the fuse way instead, can't find plastic gloves around the house...

so... I can't seem to find the 80A fuse that Breeza said, but I found one labelled 100A with a battery logo, and one illustrated as a engine and labelled FI ECU in the manual, which one should I take out...

Gloves???? You can touch the negative terminal without gloves.

It is the positive terminal that you should be careful with. Incidentally, the 100A fuse is directly connected to the positive terminal on the battery. :)

Go for the negative terminal. There won't be any sparks or electrocution as long as you don't connect the positive terminal to the chassis or negative terminal.

[Blitzen]

noob gonna try resetting the ECU, I'll cya all in another life :p

nah, thanks for the advice :)

[Accord Basic]

make sure you don't touch any metal with your body and put your feet off the ground too (shoes or foot wear). incase the current go pass and you are insulated. last time I unscrew the battery nut and the tool touched the car body then got spark and the tools melt a bit at where the touching point is. but I didn't get burn, the current just passing though on my body. very scary. hahaa. The current always go to the less resistant way. if your body didn't touch the ground. you are insulated. like a bird standing on power line. the current just passing through and no heat generated. if the bird touch the pole or ground, it will be cooked.

[Blitzen]

thx man, I actually found a pair of washing gloves and used that instead, nice Recaro's btw!

ECU now reset, didn't feel the difference but a good excuse for a Friday arvo cruise :p

[beeza]

Fully!

Mad seats man.Great photo (lighting etc).

[integral90]

[QUOTE=Blitzen;2006913]I always try to cruise at lowest possible engine speed, around 1500rpm, but that was before, nowdays I cruise at 2000rpm, and drop a gear for small hills rather than push the throttle a bit harder...QUOTE]

Also lower rpm doesn't mean lower fuel consumption. You can burn more fuel at 2k rpm WOT than 4k rpm at 10% throttle. Find the balance between the engine making enough torque to keep the car at the speed limit and keeping it at low revs with as little throttle as possible.

[beeza]

[QUOTE=Blitzen;2006913]Find the balance between the engine making enough torque to keep the car at the speed limit and keeping it at low revs with as little throttle as possible.

:thumbsup::thumbsup::thumbsup: Nicely put man.

[BusterSonic12]

does resetting the ecu seriously help?

[Blitzen]

I'll see after a few fill ups, but one thing I did notice during cold start, is the engine will now stay idle at lower rpm, it use to be 1500rpm, now it's 1250rpm

[Crapdaz]

1500 seems a bit high, mine is around 1200 mark.

[MiSloVic]

does resetting the ecu seriously help?
depending on what you have done and what you want to achieve, actually...
resetting ECU does 2 major things... clear out the long term fuel trim, and error codes... it also clears out all short term fuel trim and will 'forget' what it has learnt about your driving style... in short, it will reset to stock factory condition

if you had not mod your car and if there are no error codes prior to the reset, then, the car will return to what it was before you reset... ie, it will learn your driving style, what sort of long term and short term fuel adjustments it need to make to suit you, etc.. which means, it will not make any difference.

but if you had done some major engine mods, then, it will adjust itself to suit... so, it will make a difference in the long and short term fuel trim and maybe, when it decides to shift differently (for auto).

if all cases, the car definitely feels different immediately after reset, while it is adjusting.

[ticklenow1]

Honda didn't charge me for an "Idle relearn". How effective it was...I don't know. It can't hurt to try. Honda claimed that if I didn't get it done then I would get increased fuel economy (after i replaced the battery).
I have always got about 580 to 620k's around town and about 800 on pure highway driving.
Back when EFI first started getting popular on cars, Nanna's would bring their car's into the workshop and complain about them running rough. We would take them out for a good flogging and they would come good. That was back in the late 80's early 90's though. I am sure that modern cars are much better (I stopped being a mechanic in the early 90's) than the older cars though.

[r-r-redEuro]

i think i need to get my ecu reset and my cars an 07, :S with my previous driving style the car never shifts into 5th gear (auto) and always stays in 3rd or 4th even at speeds of 60km - 80kms.
if i am in 5th from 80km - 100km, the rev over is under 2000rpm and once it over 100kms it goes under 1500rpm. :S
and today when i was just revving it for kicks with a mate and comparing sounds of our exhaust in neutral idling, the " check system " light is on :S i gotta bring it to honda and check it tommorrow but im just wondering if any one here would know, im like so worried i cant even sleep right :(

[aaronng]

Is your Euro modded?

[tony1234]

i think i need to get my ecu reset and my cars an 07, :S with my previous driving style the car never shifts into 5th gear (auto) and always stays in 3rd or 4th even at speeds of 60km - 80kms.
if i am in 5th from 80km - 100km, the rev over is under 2000rpm and once it over 100kms it goes under 1500rpm. :S
and today when i was just revving it for kicks with a mate and comparing sounds of our exhaust in neutral idling, the " check system " light is on :S i gotta bring it to honda and check it tommorrow but im just wondering if any one here would know, im like so worried i cant even sleep right :(
Reset the ECU before you go to service,it'll do no harm and it should clear the CEL.

[r-r-redEuro]

to aaron: yeah i got an cat back exhaust on.

thanks tony for that it might help.

i went to get it checked out today, and honda said apparently my a/f sensor or some sh!t is damaged and i need it to replace it and its not under warranty costing me $450, which i dont have. :( so i just left it for now til i get the money. but i wanna ask is that part very important ? he goes its the sensor that sits on the " flexi pipe " or something

i dont know what it does, the service man didnt even tell me what it exactly does.
so im asking you guys =) thanks,

In kind regards Peter.

[MiSloVic]

if it sits on the flexi pipe, it is likely the oxygen sensor. It detects the 'richness' of the exhaust and adjust the fuel injection. If it is bad, it can cause bad fuel economy and premature cat failure.

[beeza]

Sounds like the 02 sensor.$100.

[r-r-redEuro]

i remember the dealer sayin its NOT the oxygen sensor, its another sensor at the bottom of the flexi pipe.

and whats the o2 sensor ? beeza from sydney ? sent pm.

[Blitzen]

back on topic, I really can't be bothered to fill up a whole tank to test out the fuel consumption figures per 100km, so I kept my usual routine of $31 of premium stuff and just worked on the past 3 fill ups:

27/11 - 25.22 litre = 200km = 7.9km/litre = 12.6L/100km?
1/12 - 27.8 litre = 240km = 8.6km/litre = 11.6L/100km?
9/12 - 27.8 litre = 245km = 8.8km/litre = 11.4L/100km?

so it's improving abit, I also recall a few trips where I had a car full of people and had the air con on with the wet weather...

oh and shop around for petrol, even if it's the same company, because I just filled up today, similar amount at 27.55 litre, and the fuel gauge didn't even get close to mid point (where it usually sits from the past two fill ups)

[unity]

I'll see after a few fill ups, but one thing I did notice during cold start, is the engine will now stay idle at lower rpm, it use to be 1500rpm, now it's 1250rpm

The dealer had just reset my ECU on Monday and this has been done on one other occasion. I certainly noticed a bit more responsiveness from the car. The other thing I noticed on both occasions is that the idle had improved initially. What I mean by this is that the idle was very smooth and you could barely feel any vibration. However, after 2 days the idle was back to how it was previously, and whilst it is not harsh, it is annoying.

I have posted several times on here about the vibrations at idle. Now I know it is possible for the car to idle better than it has in the past. It's just a matter of finding out why the idle reverts back to being rough a few days after a reset. It must have someting to do with the ARF.