hey ive reset my ecu by leavin the + terminal off for an hour or 2 and my car some how seems to be a bit quicker when i took it out :S

is this usually the case?

my reason to resettin my ecu was due to my poor fuel economy so i'm just curious if resetting it can help!

please give me some of your advice, help e.t.c.

many thanks.

Mufflaz2005 said:

hey ive reset my ecu by leavin the + terminal off for an hour or 2 and my car some how seems to be a bit quicker when i took it out :S

is this usually the case?

my reason to resettin my ecu was due to my poor fuel economy so i'm just curious if resetting it can help!

please give me some of your advice, help e.t.c.

many thanks.

Click to expand...

This is normal. Bosch ECU's automatically programme to the drivers style of driving over a (circa) 30 mins. So if you drive slowly the ECU will register that & you will never get the full performance available. I don't know about Fiats but certainly on VW/Audi/BMW you can reset the ECU to factory settings just by switching the ignition on (without starting the car!) for 30 secs then turn the ignition OFF for at least 30 secs. Start the car then blast it for 10 mins & the ECU will programme itself for max power.

What you did by disconnecting the battery wasw to re-set the ECU. You only need to disconnect it for 10-15 mins though.

Bear this in mind whether you buy a brand new car with a few miles on the clock (driven from the factory & on/off a RORO ferry) or a used car! - The ECU has set itself to the style of the last driver! - If it was just driving the car around the docks then expect poor performance..... The dealers don't understand this (lack of intelligence?) so virtually ALL brand new cars perform below par.

ok mate cheers for the info!

well what i did was left it disconnected for about an hour!

connected it all back up give it a few minutes to warm

and then took it for a good blast so should be okay!

but my main priority is to get to the bottom of the poor fuel consumption, i don't care about power as much.

Thanks

what punto is this mate? because the mk2 puntos need to be left overnight for the ECU to have reset and its the first 20 miles where it sorts out your driving style

it's a mk1

1108 55s!

1995

so if i pull my battery out over night and put it back in will it help my car perform better then?

thanks

As soon as you disconnect the battery the ECU will be reset. The engine will run rough for a while and willbecome smoother.

The are 2 differantmemories in a ECU


RAM and ROM


The RAM is like the memory of how you are drivin and how much fuel to put in at the temp. you are running etc...


If you drive this slowly then your fuel economy will bebetter.

will this work for mine? its a mark 1 sx 75 1242cc multipoint 8valve

me53350 said:

As soon as you disconnect the battery the ECU will be reset. The engine will run rough for a while and willbecome smoother.

The are 2 differantmemories in a ECU


RAM and ROM


The RAM is like the memory of how you are drivin and how much fuel to put in at the temp. you are running etc...


If you drive this slowly then your fuel economy will bebetter.

Click to expand...

How long is a while?
I have a mk1, 8V 1.2. I've timed it up correctly but its really really rough.

The battery had been disconnected over night.

Sorry to high jack the thread, but does this mean if a punto jtd has had a remap and the battery goes flat then the remap is forgotten? Cheers

PuntoJTD1.9 said:

Sorry to high jack the thread, but does this mean if a punto jtd has had a remap and the battery goes flat then the remap is forgotten? Cheers

Click to expand...

no that part of ecu dont reset, just its learning bit does

I just remove the battery cables and touch them together to discharge any left over power, no waiting around then. Best to leave it off i suppose but i'm impatient.

easyrider81 said:

I just remove the battery cables and touch them together to discharge any left over power, no waiting around then. Best to leave it off i suppose but i'm impatient.

Click to expand...

all you need to do diconnect negative terninal,
then put key in ignition and turn on and leave it for 10 mins,
then reconnect your battery ,
start car and let it idle for about 10 mins,
turn off engine,
Now go for a drive

There are so many myths about this.............

There are no capacitors in there -- as soon as you break the circuit, job done. Have a cup of coffee if you like, but....................

i went out with a myth
were married now

if everything is working correctly why would anyone want to disconnect the battery?
cant see how a car would perform better after a lead off
think about it the ecu gets its data from the sensors, if one is faulty it just uses stored data which is factory set so your particular car cant be working optimally
one may as well substitute the lambda and cts with 10k resisters
available now from me only £9.99

Yep.

It'll clear faults, force the ECU to re-learn, but it sure won't improve performance.

Yup, confirmed. Disconnect the ground and reconnect. Done! Thank you!