resetting ECU?

[wirdy]

I've seen a few posts where members have had their ECU's reset. Sounds like the brain had adapted itself to normal 95 octane unleaded and this reset gave the brain a chance to remap itself?
Does anyone know how to do this DIY or does it need to be done by a dealer. I would assume its a case of shorting one or two pins together on the ECU? or can you unplug the ECU and does it reset itself after a set time?
I still don't know whether my VR-4 has suffered this, but I'd like to try just to put my mind at rest now!! I begrugde filling her up with optimax now until I get this idea out of my mind. It's maybe subjective though, and after a year of ownership the performance becomes 'normal' INSERT INTO post VALUES (until you get back into a 'normal' car again--that is!!)

[Spirit]

Just disconnect the battery and it will reset itself - common opinion is from just 30 seconds to 30 minutes

[wirdy]

Thanks, I'll give it a try. Guess I have to find out one day whether my Sony head unit has a security code or not!

[Brind]

My car suffers from this fairly often, I have had to use normal 95ron in emergencies due to running the car on fumes anyway and the poxy Shell garage near me keeps running out of Optimax! :mad:

I can assure you removing the negative cable from the car battery for 1 minute, less time is required but a minute will ensure it has worked is all that is needed.

When I use normal 95ron which is on rare occasions, the car will go into safe mode guaranteed.
Once using Optimax, reset the ECU and she goes like a rocket again. VERY noticeable difference.

[pjjohnson]

Brind, when you reset your ECU, can you notice any effect on the gearbox?

I INSERT INTO post VALUES ( well one of my kids actually ) managed to leave an interior light on for a few days so the battery went dead causing, I presume the ECUs to reset themselves. I felt no difference in how the car went but the gearchange was awful. Really jerky between 2nd and 3rd, and very very slow between 3rd and 4th. It took about an hour of driving to get the 2nd to 3rd smoothness back, but 3rd to 4th is still pretty slow.

[Brind]

When the ECU goes into safe mode the whole car is MUCH slower, you seem to have to push the throttle that slightly bit extra and there appears to be no real power down the bottom.
The gearbox isn't jerky in the slightest but you do have to wait slightly longer for it to change up and down when you really boot it, but saying that when you hit 38mph it goes into 5th as it would when the ECU is working properly.

When the ECU is working properly the VR-4 is a completely different driving experience! you have hardly got to touch the throttle and it's leaping forward and really throws you back into the seat.. when you cruise and then put your toe down she doesn't hesitate to jump down a gear and go like a bat out of hell!

The only real gearbox problem if you can call it a problem is when the car has just been started and she wants to rev up to stuped rpm's before changing out of 1st and 2nd.

I rarely rag the car so I doubt my driving style is much different to the gearbox's pre programed setup.

[Pescha]

My mitsubishi dealer mechanic has told me it only takes 30 seconds to reset the ECU thru taking the battery terminal off. I physically rang him on behalf of the club to ask that question when it arose the last time!

Cheers,
Pescha!

[SGHOM]

followed on screen instructions, disconnected battery for around 3 or 4 mins, recconected, started her up & ................................................. no tickover !!:Ponder: car seems to drive just fine, but each time I stop, it cuts out ??? I left foot brake, so its not a real problem for me, but any suggestions??

[-LegnumVR4-]

Originally posted by Brind

The only real gearbox problem if you can call it a problem is when the car has just been started and she wants to rev up to stuped rpm's before changing out of 1st and 2nd.


Thats just the transmission oil when it's cold. I have a transmission cooler on my car and gear changers have rev'd up changes untill about 3mins of driving then it's fine once it get to it's set temp. As far as what I've heard the auto's ECU learns your driving style after awhile once your've resest the ECU.

Interlec, what do u mean by no 'tickover'? When the car cuts out does the car just die? No power? Maybe check the battery connections or replace the battery.


Rhys

[SGHOM]

its slowly coming back ?? :Ponder: if I let the revs drop quickly, ie; when braking, the tickover was so low that the engine just stalled. its not the battery. I've just let it idle for a few minutes, & it seems to increasing the idle speed. its now at around 500 rpm, which is still a bit low.that obviousley drops when you put the car in drive. I also just switched on the air con, & that was enough to drop the idle to such a level that the engine stalled !!! seems to be increasing slowly now, so I think she'll live :D :D

[Simon]

After disconnecting our battery .......and reconnecting we started her up and straight away put her in tiptronic and drove off...up through the gears hard! not 100% acceleration but enough to put you in your seat. Then stopped, put her into auto and all was fine. Found she ticks over at 600rpm'ish now. See if that helps.

[Brind]

Thanks for the info Rys.:)

Interlec, whenever I've reset the ECU I only do it after using 98ron Optimax which the car is happy to run on unlike normal 95 basic unleaded.
I have no idea if it makes a difference but it wouldn't surprise me, did you reset after using the normal 95ron fuel? being a lower octane the ECU may have more of fit seeing a lower octane instantly than it would if it was just gradual and mixed in an emergency wiith higher octane fuel..

Mine will tickover at 500rpm aswell, whichever fuel I've been using. Use the air con and while the pump is running the idle hangs around 1000rpm.

She never wants to die though.

[Spirit]

Have reset me ECU many times and can honestly say I have never had a problem like you guys are getting :Ponder:

Mine INSERT INTO post VALUES (once warmed up) happily ticks over at the normal 650rpm INSERT INTO post VALUES (dead accurate with the Apexi RSM)

[SGHOM]

reset the ecu after filling up with 98 ron BP super unleaded. optimax is a 10 mile drive away from me !! I must admit I did panic a bit when she wouldn't keep running on idle. :INSERT INTO post VALUES ( but all seems ok now, apart from persistent misfire at low revs. dealer said they could find nothing wrong, but I know it's there. this may sound strange, but it feels like a fuel/mixture problem, but when I lift the bonnet & listen, it definatley sounds like a HT lead arcing ??:Ponder: every few seconds, a sound of 'sparking' & the revs drop momentarily.?

[zedy1]

only has three ht leads take top cover off and have a quick peep under it if its sparking at the rear the you have an isse

[SGHOM]

I'll try that Mo, thanks. can I take it that only the front three HT leads are accessible then ?? is it a problem to get to the back ones ??

[Brind]

To get to the rear plugs you have to remove or at least release the manifold.

I can't see you will have this problem now, just after resetting the ECU.

Try resetting the ECU again, maybe it was made by Bill Gates and it has bug in it.
Check for air leaks as well as plugs or leads if the problem persists.

[zedy1]

there three coils on the front three plugs then each coil has one ht lead going to the rear plugs

[4me]

Thankyou thankyou thankyou thankyou. :wiggle:

I thought my car was beginning to die. Wastegates keep clicking open, performance seemed sluggish, felt heavy.

Read this thread and remembered the tank of 96 I had to put in a few weeks back when out of range of a suitable petrol station.

Reset the ECU as per instructions and took it for a 30 minute drive up the motorway. Idle was a bit suspect at first as described, but is now fine as is the performance of the car.

No more wastegate clicks and clunks either!