Technical Ecu reset

[Vangelis]

I have a mk2 punto sporting . My question is does the ecu resets and reprograms by itself while driving ? How do I know it's reset ? I have unplugged the battery for an hour then connected again and the clock on the dashboard was reset does this mean the ecu is reset ? I have done this while my engine was misfiring due to a faulty spark wire so it was running on 3 cylinders . Now I fixed it running in 4 but I experience lower performance than before and I was wondering if the reset while misfiring programmed the ecu in this way and performing bad . Please share your knowledge about the ecu

 

[fingers99]

The ECU "learns" the engine. Resetting in that way removes the learning, so it has to re-learn. Shouldn't take much more than 200 miles.

The clock has nothing to do with the engine ECU.

 

[Vangelis]

Could it be reprogrammed and learned the misfiring engine and now perform bad ? How do I know for sure when the ecu is reset ? What's the reset procedure ?

 

[oldhammer]

just take battey lead off for 20 mins,
put lead back on,

start engine,
go for nice steady run for say 10 miles,

Mpg will be poor to start with but it will pick up,

this works on mine,

there is a procedure for throttle relearn via ignition key but iforgot how its done,
this saves messing with battery leads,

 

[Ziggy122]

if your on about the throttle relearn - its ignition on wait 30seconds without touching owt

or something like that

What the OP is asking i think is the Phlonic wheel learn process

This requires software such as MES (Multi - Ecu - Scan) To reset the ECU
This will leave the ECU flashing, so you need to let the engine idle to warm up untill the fan kicks in
Then blast the throttle upto 5000rpm and let it settle to idle
repeat the 3 throttle blasts and the light SHOULD go out

Ziggy

 

[fingers99]

Could it be reprogrammed and learned the misfiring engine and now perform bad ? How do I know for sure when the ecu is reset ? What's the reset procedure ?

No.

Proper way is just to delete the codes with a code reader (saves the relearn). But if the EML light isn't on, your way worked fine.

 

[oldhammer]

Ive never bother'd with M.E.S/F.E.S for this tbh,

it shouid be able to relearn withought the need for a plugin if no access to fes/mes.

but iagree with fingers, delete old codes stored if any basic code reader does the job?

 

[Vangelis]

I want a "do it yourself" solution . I do not have a rom flasher for the ecu . So I disconnect the battery for 20 minutes and how do I know it's reset ? Then what's the proper use of the engine for the ecu to learn ?

 

[fingers99]

You can buy a code reader for well under £20 that'll do it. You're not flashing ROMs. Just drive the car!

 

[Vangelis]

So with a obd2 reader I can force the ecu to forget the settings and learn while I drive . There are rumors around various forums about that learning such as a blast drive makes car faster or economy drive does the opposite . Is there any truth ?

 

[fingers99]

No -- you clear the codes with the obd2 reader. You make the ECU reset by disconnecting the battery. It relearns, but anyone who tells you the other stuff probably believes that white phosphorous is good for your health.

 

[Vangelis]

Ok I ll try it as soon as possible and report back any changes noticed

 

[s and b]

No -- you clear the codes with the obd2 reader. You make the ECU reset by disconnecting the battery. It relearns, but anyone who tells you the other stuff probably believes that white phosphorous is good for your health.

is it not then
have i been lied to via a smokescreen

 

[huck1975]

Hi All. Ive got a 2002 Punto active sport. The other day my engine management light popped up. My first point of call was here (had issues before and found the best advice here) and read all about the reset of ecu. it was very sluggish and power kept dipping to an almost stalling engine. So I disconnected the battery and discharged any surplus power, left for 1.5hrs, reconnected battery, let engine warm up for 5 mins (was still very lumpy and erratic) took for a steady 30mph drive and it was juddering at first then cleared out(didn't before when first noticed issue) then parked up and sat idle for another 10 mins and light was off and all seemed fine. Just been out and light came back on but not running bad like before? Can anyone throw and ideas out that will help.

 

[varesecrazy]

get the fault code read..,

only read way of diagnosing fault..,

when were plugs / leads last changed?

Charlie - Oxford

 

[huck1975]

get the fault code read..,

only read way of diagnosing fault..,

when were plugs / leads last changed?

Charlie - Oxford

HI varesecrazy, I have owed the car for 6 years and have not changed the plugs and leads in the time ive owned it, I have changed oil and filters and had an awful lot of work done (head gasket,sump,water pump,canbelt,thermostat,steering column x2 due to power steering failing) but not the plugs and leads as its always been smooth and is smooth again now. I read in a recent thread that the coil pack throws out a false code to ecu and causes the light to stay on. Will it be possible say to change plugs and leads and get the light reset when plugged in. Ive got to take it to garage at 9am tomorrow. I appreciate any help offered.

 

[varesecrazy]

Hi,
Plugs and leads are cheap and simple,

TBH- if you've had the car for 6 years.. I would recommend a basic fault code reader.., at @£10 it'll pay for itself in it's 1st use

Charlie