Third Gen Magna
TE V6 Manual
Disconnected battery to connect foggies now runs ok but stalls coming to a stop....

Disconnected -ve terminal still no avail...

Question
:lurk: How do i reset the ECU? and how long do i leave the negative terminal disconnected so it forgets everything? The how long do i drive it for or what is the proceddure so it dont stall coming to a stop?

(That is if disconnecting the -ve terminal is the right way to reset it)

What could be causing the stalling all of a sudden?


Did a search... Nothing of use

If you don't need the car for the rest of the night, the best way to guarantee it would be to d/c the terminal and leave it off overnight. TIs a bit of overkill, but it makes 100% sure ;)

Generally, 10-15 mins should suffice. It doesn't really matter which terminal you take off, either way you're breaking the circuit to the battery.

Then once you've reconnected it again, let the car idle for 5 mins, then take it for a 5 min run, and just drive it how you would normally. The way you drive it 'determines' how the ECU is reprogrammed... However, as you drive it more it will do it's own recallibration and adjust to your driving style as you go... :)

Hope that helped...

Third Gen Magna
TE V6 Manual
Disconnected battery to connect foggies now runs ok but stalls coming to a stop....

Disconnected -ve terminal still no avail...


What could be causing the stalling all of a sudden?



You most likely already have reset the ECUto connect the foggies. The stall coming to a stop is the CPU no knowing itself yet, and has to do a bit of learning before it figures everything else out. Keep driving for a bit and it will all be good....99% of the time.

It's a common problem. You may also have experiences a funny idle as well, idling much lower almost to stopping, then the ECU corrects.

Just keep driving around. It should fix itself in about 30 mins of driving.

The way you drive it 'determines' how the ECU is reprogrammed...

This is complete rubbish.

The 'learning' capabilities of the ECU are extremely limited.

This is complete rubbish.

The 'learning' capabilities of the ECU are extremely limited.

Rubbish eh!?

So you're saying that they're limited... Granted.. I agree with that... This would mean that there are some 'learning' capabilities... ie: 'determines'... Hence the reason for the quotation marks ;)

I thought it was stated in the manual about learning the driving habbits etc? and this was in my TE manual. Didn't bother about it as my Magna doesnt show how am I driving for fuel efficiency.

People talk about the ECU "relearning" like it is some huge tuning tool worth many extra kw's available if you thrash the **** out of the car after the ECU is reset.

Saying things like "the CPU not knowing itself yet" is complete bull****.

If the car is stalling - something is wrong that isn't gonna fix itself by unplugging the battery for a few hours.

Third Gen Magna
TE V6 Manual
Disconnected battery to connect foggies now runs ok but stalls coming to a stop....

Disconnected -ve terminal still no avail...

Question
:lurk: How do i reset the ECU? and how long do i leave the negative terminal disconnected so it forgets everything? The how long do i drive it for or what is the proceddure so it dont stall coming to a stop?

(That is if disconnecting the -ve terminal is the right way to reset it)

What could be causing the stalling all of a sudden?


Did a search... Nothing of use
The cause of your stalling may be due too how you run the car after you reset the ecu i dont think it matters so much how long you leave the terminal off for but it does matter that when you start the car you let it IDLE FOR 10 to 15 MINS when you first start it. Another member had the same problem after dissconnecting the battery.After following this advice all was normal again.You have to let the ecu set itself up again at idle for 10-15mins.
Hope this helps you.:D

The cause of your stalling may be due too how you run the car after you reset the ecu i

This is not possible in a million years.

This is not possible in a million years.
Go read this thread in the third gen section then smartass!:gtfo:
Car stalls after battery gets reconnected
http://www.aussiemagna.com/forums/showthread.php?t=33858&referrerid=1069

HAHAHAHAHA

It happened to ONE person and you think it's a common thing?

How about the other people in the thread saying "it doesn't happen to me"?

:gtfo:

HAHAHAHAHA

It happened to ONE person and you think it's a common thing?

How about the other people in the thread saying "it doesn't happen to me"?

:gtfo:

Well how about something constructive rather than the usual bull **** you contribute. ;)

No one ever said that there were kw's to be gained from the so called 'learning' capabitlities of the ECU. Basically what they allow for is smoother gear changes in autos, and more comfor stuff like that...

Go ahead... If you've got somehting to contribute, contribute it. Otherwise STFU!!

Atleast some of us here are offering suggestions as to the cause of the problem, rather than sitting back and quoting other peoples posts, sayign they're bs, and not giving any proof as to why you THINK they're untrue...

HAHAHAHAHA

It happened to ONE person and you think it's a common thing?

How about the other people in the thread saying "it doesn't happen to me"?

:gtfo:
Funny that eh you must have more knowledge than a RAA mechanic cause thats what they told me when they replaced my battery and I will check but I am sure it says something like that in the car owners manual.Nice to see some supportive info from a fellow S.A member how bout you offer some assistance instead off just adding your smartass comments as you have also done in other threads.:bowrofl:

I'm sorry - I thought i was contributing by giving correct information as this was helping people.

I'm surprised the you think giving people completely wrong information is a good thing.

.Nice to see some supportive info from a fellow S.A member :

Hey i don't discriminate between states.

If you're giving someone wrong information - i'll let you know regardless of where you are.

I'm sorry - I thought giving correct information was helping people.

I'm surprised the you think giving people completely wrong information is a good thing.
Where's your contribution I am letting him know what I was told by a Mechanic who i beleive would be more qualified than you unless your a mechanic.
It worked for me and TE96 and a few others I have suggested it too so I dont know how you gather it is completely wrong information.:nuts:

HAHAHAHAHA

It happened to ONE person and you think it's a common thing?

How about the other people in the thread saying "it doesn't happen to me"?

:gtfo:
And when did I say it was a common thing I said it MAY be the cause.:gtfo:

I have fiddled with ECU mapping with a friend so i know where the variables are.

If the car is stalling, it has nothing to do with the ECU being reset and is a complete coincidence.

I would be looking for ECU fault codes for a more definate diagnosis as it could be caused by hundreds of things.

My helpful point of advise?

Go to your local mitsubishi dealer and ask them to check the ECU for fault codes.

I have fiddled with ECU mapping with a friend so i know where the variables are.

If the car is stalling, it has nothing to do with the ECU being reset and is a complete coincidence.

I would be looking for ECU fault codes for a more definate diagnosis as it could be caused by hundreds of things.

My helpful point of advise?

Go to your local mitsubishi dealer and ask them to check the ECU for fault codes.
I can fiddle with things with my freinds too doesnt make me a expert!:bowrofl:

I have fiddled with ECU mapping with a friend so i know where the variables are.

If the car is stalling, it has nothing to do with the ECU being reset and is a complete coincidence.
I would be looking for ECU fault codes for a more definate diagnosis as it could be caused by hundreds of things.

My helpful point of advise?

Go to your local mitsubishi dealer and ask them to check the ECU for fault codes.

You are wrong TL-R.

If the battery has been disconnected, this is what happens. I have experienced it first hand on a TJ. Was running perfectly before the battery was disconected, after it was idling really badly like it was about to stall, and sometimes did stall. After letting it idle for a while, and driving it went back to normal.

TL-R..... i think you should kinda settle abit.... I KNOW where your coming from... But the way you voice it out isnt particularly proper.... Ok you may disagree with peoples posting.... but you might want to state what is wrong and then try to give a solution...

I notice this in alot of threats that you reply to.... lol

so instead of one sentence 'dissing', try to word it in a different way ay??.....

Ok - i'm wrong.

Care to explain why resetting the ECU causes the car to stall?

The ECU has a default set of values for mixture etc and the variation component is very minimal and mainly (or ONLY if i remember correctly) in the 3k-redline rpm range.

so instead of one sentence 'dissing', try to word it in a different way ay??.....

Point taken.

I have done this alot (disconnect battery) and everytime after that, it wants to stall. So yeah. Let it sit there for 5 - 10min on idle, and then drive around a little, and then stay stationary with the gears in 'D'. It will feel like the engine is going to stall, as revs drop below 600RPM and will feel rough, but when you wait, you will notice that the engine slowly increases the RPM automatically to about 600 - 800RPM. It will take a few stop and go's, but be patient, and it will settle.

*EDIT* it will stall sometimes while in gear while motionless or decelerating, as the engine has to basically 'learn' where the revs have to sit during idle. So dont get worried if it stalls. Just start car again, and keep going.

, as the engine has to basically 'learn' where the revs have to sit during idle. S.

Idle speed is a default value and does not have to be learned by the ECU.

Idle speed is a default value and does not have to be learned by the ECU.
Then you explain it mate ;) I know it should be a default value, however this is just how it 'feels' and appears like. I know its a set value.

I've also experience the "stalling when comming to a stop" after disconnecting battery in my TJII auto. I was usually pretty careful about letting the car idle for 5-10minutes after disconnecting the battery - but on one occasion I didn't, and the car stalled in D when I came to a stop at the end of my street, and "threatened" to stall a couple of times after - until it had been driven normally for about 10 minutes.

So as far as I'm concerned - it is a 'feature' of the automatic models, and not a myth. Besides, I'm pretty sure I've read somewhere (either the owners handbook, or the haynes service manual) that you should let the car idle for 5-10 mins after disconnecting the battery, and if my memory serves me correctly - well why would they write it if there was no reason for doing it.

If you know it's a set value - why did you say the ECU has to learn it? It's a contradiction.

So as far as I'm concerned - it is a 'feature' of the automatic models, and not a myth. it.

AHH - now we're getting somewhere.

Maybe this has something to do with the TRANS ECU?

This sounds much more plausible.

This is not possible in a million years.
Plausible now is it? The process is what I was trying to get across.:D
i.e let it idle for 10-15 mins.As some one else has also stated that remember reading in the owners manual or workshop manual.

Do I have to spell it out for you?

Engine ECU - Impossible

Trans ECU - Possible.

Now how about we try and get on with finding the answer.

AHH - now we're getting somewhere.

Maybe this has something to do with the TRANS ECU?

This sounds much more plausible.

An ECU is and ECU... No matter what the function of that specific module is.... ;)

Just cos no one mentioned that it may be the trans ecu which needs to 'learn' how to operate again... Still, some learning needs to be done by AN ecu....


I have fiddled with ECU mapping with a friend so i know where the variables are.

If the car is stalling, it has nothing to do with the ECU being reset and is a complete coincidence.

I would be looking for ECU fault codes for a more definate diagnosis as it could be caused by hundreds of things.

My helpful point of advise?

Go to your local mitsubishi dealer and ask them to check the ECU for fault codes.

:think:... Interesting....

Everyone was refering to the engine ECU in this thread as was i in the quote you gave above.

Everyone was refering to the engine ECU in this thread as was i in the quote you gave above.
So you're admitting that you're wrong!? :noway:

Anyway... d/c the battery for a while... drive for 10-15 mins and everything will be :thumbsup: ;)

/me out

This thread is getting ridiculous.

Everyone was refering to the engine ECU in this thread as was i in the quote you gave above.
I never stated what ecu you just assumed!

So are you saying you meant the Auto ecu all along?

Give it a break TL-R. You were wrong. Mods?

How was i wrong?

So are you saying you meant the Auto ecu all along?
No I was referring to the engine ECU but you are so critical of what everyone says but that doesnt apply to yourself I still believe that the engine ecu must do some sort of learning in some small way.That doesnt matter now anyway cause it seems no matter what people say you are ready to try and shoot them down in flames.I come on here to try and help other magna owners not just to spoil for an argument.
:D
Goodnight!!

This thread is getting ridiculous.

here here. Oh and I'll give ya's all a bit of advice about my mate TL-R :cool: .

The more of a reaction he gets, the more he likes to push it lol

In the interest of forum harmony - i won't post any further in this thread.

In the interest of forum harmony - i won't post any further in this thread.

See what I mean!!!????

He's just saying that to make a liar out of me :D

Crazy kidder :bowrofl:

*Edit* - woot 2,000th post!!!!! yay me. And to think - I owe it all to responding to TL-R's spam. Well I'm not gonna post for a few days now cause I like the look of that number under my name so much. See yas!

I'm sorry - I thought i was contributing by giving correct information as this was helping people.

I'm surprised the you think giving people completely wrong information is a good thing.
From all the posts you given, only one actually helped. Other posts of yours in this thread you are criticising people and makeing them feel stupid. We all made different experiences.

I never mentioned once that im talking about the ECU. Plus i said it 'FEELS' like its learning... as the revs slowly build up. So, unless you have something of interest to say instead of criticising people, then dont post mate. I have nothing against people correcting others, but making them feel dumb or being picked on.. is not a good thing. We are all just trying to help here

People talk about the ECU "relearning" like it is some huge tuning tool worth many extra kw's available if you thrash the **** out of the car after the ECU is reset.

Saying things like "the CPU not knowing itself yet" is complete bull****.

If the car is stalling - something is wrong that isn't gonna fix itself by unplugging the battery for a few hours.

Happened on my TR auto. Happened on my KH auto. Can't comment on manuals.

This is my take on how it works. The ECU is running in a closed loop. The defaults would say for 500RPM idle, add this much air, and this much fuel to begin with. But what happens if that doesn't work, not all engines have the same oil, exhaust etc. The ECU constantly adjusts to achieve this 500RPM idle. It doesnt know exactly where it is, it must find it.

The engine ECU DOES NOT LEARN driving habits....very true. The auto ECU does. Thrash it and it will shift up at higher revs and shift down more happily.

Also, playing with the map/mixtures has nothing to do with idle speed. Coz when u put your foot down, all bets are off with 14.7 and then the map comes into play.

Well did it work? lol. After such a bloody long discussion I sure hope it does. :bowrofl:

Cool guys, small issue lets move on.

You are wrong TL-R.

If the battery has been disconnected, this is what happens. I have experienced it first hand on a TJ. Was running perfectly before the battery was disconected, after it was idling really badly like it was about to stall, and sometimes did stall. After letting it idle for a while, and driving it went back to normal.
He's not wrong. The ECU does stuff all learning. The ECU does not magically loose it's ability to control the vehicle in which it's installed. There's learning for your recent driving which affects the automatic transmission and sometimes a vehicle may see better results from idling for 5 mins after a reset. I know my car and my mates cars have never had any issues with having the battery pulled in all the countless times it's happened.

Well I know mine and other cars have had issues after the battery has been disconnected.
We know the auto trans ECU has some "learning" in regard to shift points etc. No one is talking about that. What we are talking about is the car idling speed being very low and the car stalling, after a battery disconnection, and this has been experieced by numerous people on this forum. I don't know if the ECU is "learning"or not, but it is doing something to get the idle speed/timing/mixtures at the correct levels. No one is saying it "magically looses its ability to control the vehicle it is installed in". But surely it is quite capable of gathering data after a reset to store in RAM to help it better control the engine, which is after all its purpose, right?

Well I know mine and other cars have had issues after the battery has been disconnected.
We know the auto trans ECU has some "learning" in regard to shift points etc. No one is talking about that. What we are talking about is the car idling speed being very low and the car stalling, after a battery disconnection, and this has been experieced by numerous people on this forum. I don't know if the ECU is "learning"or not, but it is doing something to get the idle speed/timing/mixtures at the correct levels. No one is saying it "magically looses its ability to control the vehicle it is installed in". But surely it is quite capable of gathering data after a reset to store in RAM to help it better control the engine, which is after all its purpose, right?
Agree 100% exactly my experience.That is what I and a few others was trying to pass on till we get told we are full of it!:D
P.S I wonder if havocstarter has tried this yet and whether it has solved his problem or not?

Thanx guys for ur input...
Fixed that morning...
I was not letting car idle... rather getting in and driving it..
Drove it around for 30 mins to a mates workshop, he said go to work and come back tomorrow if it aint fixed. As i came home. Problem fixed itself... And car is now back to normal and even idles lower than before and does not hunt for the revs in idle!

So yes. letting it idle for about 5 mins does do the trick!

So yes. letting it idle for about 5 mins does do the trick!
Glad to hear it is fixed mate!
Letting it idle after connecting battery
Cost=free
Taking it to mitsi to get error codes checked=Cost money for something not necessary!

This is not possible in a million years.
Thanks for giving the correct information and rubbishing half a dozen or so members in the process.And sending me two Pm's after you stopped posting in this thread telling me I had a problem and I was misinforming people.:nuts:

time to lock the thread maybe? - it has achieved it's purpose - but still allows flaming......

6 pages to answer something that would take maybe a line to write? geez....:nuts:

6 pages to answer something that would take maybe a line to write? geez....:nuts:

Thanks for your informative input... Now if you've got nothing better to do than add to the 6 pages :gtfo:

6 pages to answer something that would take maybe a line to write? geez....:nuts:
Funny that isnt it!Many of us would not off continued posting if we all werent being told we were wrong!The solution was posted on the very first page.:D
And you and ribic werent voicing your opinions.Till now.:bowrofl: :D

Just had a read through this thread and made a mental note to let car idle after disconnecting battery.
However it got me thinking about the ECU's in the 3rd gens and how they work together. I suppose the tranny ECU tells the engine ECU that a gear has been selected and the engine ECU compensates for the extra drag on the motor. If the tranny ECU does not tell or is a bit slow I suppose the motor could stall when D is selected or the A/C is turned on or when the steering wheel is at full lock and more strain is on the power steering pump (BTW the engine ECU does not know when the car is at full lock and that is one of the main causes of stalling).
So I guess the best thing to do after a battery disconnect is to let it idle and also engage D, switch the A/C on and turn the wheel from lock to lock to let the engine ECU know the base revs it needs to keep the motor going.
My 96 TE does rev up to 1500 just after starting and then settles down to 700-800 and goes down a bit more when D is engaged. Might be time for a reset:D

Just had a read through this thread and made a mental note to let car idle after disconnecting battery.
However it got me thinking about the ECU's in the 3rd gens and how they work together. I suppose the tranny ECU tells the engine ECU that a gear has been selected and the engine ECU compensates for the extra drag on the motor. If the tranny ECU does not tell or is a bit slow I suppose the motor could stall when D is selected or the A/C is turned on or when the steering wheel is at full lock and more strain is on the power steering pump (BTW the engine ECU does not know when the car is at full lock and that is one of the main causes of stalling).
So I guess the best thing to do after a battery disconnect is to let it idle and also engage D, switch the A/C on and turn the wheel from lock to lock to let the engine ECU know the base revs it needs to keep the motor going.
My 96 TE does rev up to 1500 just after starting and then settles down to 700-800 and goes down a bit more when D is engaged. Might be time for a reset:D
When I did mine mate I just left it in park and let it idle for 10 mins and it was fine I think it has more to to with the air/fuel ratio than anything but I am no expert just know what has worked for me and a few others.Havent heard anything about putting in drive or turning the steering wheel.:D

When I did mine mate I just left it in park and let it idle for 10 mins and it was fine I think it has more to to with the air/fuel ratio than anything but I am no expert just know what has worked for me and a few others.Havent heard anything about putting in drive or turning the steering wheel.:D
Yeah well if Microsoft had anything to do with I suppose a 10 minute reboot is not too bad:rant:

Yeah well if Microsoft had anything to do with I suppose a 10 minute reboot is not too bad

lol......... :doubt:

You so funny... :roll:

Problem fixed.. let the thread die a slow and painful death now.... ;)

Funny that isnt it!Many of us would not off continued posting if we all werent being told we were wrong!The solution was posted on the very first page.:D
And you and ribic werent voicing your opinions.Till now.:bowrofl: :D

Mate, not trying to flame things more, but for 1. I only just read the post, hadnt seen it before and 2. as you said yourseld, the thread starters question was answered on the first page, so what else was there to add to the actual question, maybe I shouldve just PM a Mod and made my suggestion - It seems a number of people a getting a bit testy on this forum at present.....I was only making a suggestion about the thread...im sure you will agree it has served it's purpose.......

Third Gen Magna
TE V6 Manual
Disconnected battery to connect foggies now runs ok but stalls coming to a stop....

Disconnected -ve terminal still no avail...

Question
:lurk: How do i reset the ECU? and how long do i leave the negative terminal disconnected so it forgets everything? The how long do i drive it for or what is the proceddure so it dont stall coming to a stop?

(That is if disconnecting the -ve terminal is the right way to reset it)

What could be causing the stalling all of a sudden?


Did a search... Nothing of use


Hi Havocstarter

This (apparently official) advice was posted by another AMC Member (sorry I didn't record his name at the time)

PROCEDURE FOR RE-LEARNING ENGINE / TRANSMISSION

The following procedures are to be used if driveability problems are encountered after power loss or battery removal. These procedures may provide an aid in eliminating these problems and reduce the possibility of complaints after any service or work requiring the battery be removed.

Vehicles equipped with engine or transmission computers may require a relearn procedure. Vehicle computers memorize and store your vehicle operation patterns for optimum driveability and performance; removing the power results in the computers losing this saved data. The computer will then use default data until new data from each key start is stored, this can take up to 40 key starts.

Customers will often complain that their cars suffer from 1 or all of the following; Harsh / poor shift quality, rough or unstable idle, hesitation or stumble, rich or lean running and poor fuel economy.

To reduce the possibility of the above Mitsubishi Motors recommend doing the following;
Set parking brake and start vehicle in P or N, warm up vehicle until cooling fan
cycles.
Select D and allow vehicle to idle for I minute.
Drive normally using 20% - 50% throttle until vehicle hits top gear
Cruise at light to medium throttle for 5 minutes.
Decelerate to a stop, allowing vehicle to downshift and brake normally.
Repeat if required.

Cheers, Barry

Mate, not trying to flame things more, but for 1. I only just read the post, hadnt seen it before and 2. as you said yourseld, the thread starters question was answered on the first page, so what else was there to add to the actual question, maybe I shouldve just PM a Mod and made my suggestion - It seems a number of people a getting a bit testy on this forum at present.....I was only making a suggestion about the thread...im sure you will agree it has served it's purpose.......
Sorry I do not mean to have a personal go at you.But I did post the same information in another thread and no one told me I was full of it (which is also listed on the first page) and I posted no more in fact the thread author posted A thumbs up for the info.It just got extremely annoying to be told that my theory was not correct and that I was giving incorrect information by one member in particular.I was trying to defend myself and a few others.
Did not mean you any ill feeling just got the wrong idea from your post that you didnt think I should be sticking up for myself and others.
Peace Brother:D
P.S Thanks Barry for the post above about the correct procedure! Top stuff!!

Wow this thead is out of control.. Someone get a bucket of water..:P


Had this happen to a auto when it had a flat battery..

Mits service said run it for 30 mins at idle and it will be alright.. Also think they had something plugged into car to fix it for 30mins.. cant remember now.. few years ago..:D

Just stumbled across this thread whilst doing a search for "ecu problems". Very interesting apart from TLR's crap. My 2000 TJ sport tiptronic has been suffering from some ordinary shift quality of late, as well as the infamous rough idle syndrome. The car is not thrashed often, has only 95000kms, So shouldnt have a stuffed tranny yet, so I did the battery disconnect, ecu reset. Bingo. Gears now shift up and down quicker and smoother, idle better as well. This reset is definitely fact, not TLR fiction.

My car had the same problem after I d/c the battery.

It's a 97 TF 3.0 V6 Manual.

I was told by a mitsi mechanic that the reason it did this is because out of the factory the ECU assumes a certain fuel/air mixture for idle. BECAUSE my car is in need of new sparkplugs and possibly a slight tune up, teh factory set fuel/air mix will not sustain the RPM at idle. If my car had not needed the plugs/tune, then I should take the car into a mechanic and get an error code reading because there is something wrong.

Simple fix: start and idle til at normal driving temp.