Reseting the ECU/TB - Question for the techies

[Pabs]

Hey guys/gals,

When you reset the ECU (battery disconnect or whatever) the car ALWAYS feels stronger, more powerful and seems far more responsive.
I put this down to the car having to "learn" and adapt again.

So, Question:
Why is this so? Surely, if it feels quicker after a reset, then it must get "bogged down" or slower once it's adapted. Surely it would adapt to the best settings......

In other words, if indeed it is quicker - i can only assume it's pushing the engine harder - does this mean that it'll be seeing higher CF's on the cylinders etc? And if this is true, would it not push the car too hard and end up killing various engine components?

Just something I've always wondered - I reset my ECU today as the car didnt feel like it was running quite right (and i hadn't done this since fitting the new panel filter) and it's SOOO much better now!

Answers on a postcard (or, perhaps below!)

 

[mALLA]

Are u running revo? or what map u got mate?

 

[Pabs]

I don't really see why that would matter (to my question) as it also occurs on a standard car - but yes - I run Revo stage2 (+ all mods)

Another related question - but revo specific - if you reset the ECU, do the Timing and Boost settings revert to the standard 6/6 (i think it's 6/6 anyway), or do they keep the settings that have been put in by the SPS3 device I have...

 

[Cowie]

i tried this with mine last night pabs,its been kinda sluggish and unresponsive for a couple of weeks now so thought would give this a try,like you,i don't understand the logic why it should make a difference,but hell yea the car feels like it did when i first got it again,the sluggishness and lag has gone,all i can say is wierd but good

 

[Mitchy]

The only way to do it surely is to have a vagcom session before, logging MAF and boost, and then a vagcom session after a reset to see if the values have changed.

If not then its all probably in your head

 

[Cowie]

 

[gazjones]

the revo settings will stay the same after an ecu reset, so what ever you had them set at

 

[Snoopie]

I would never worry about killing components, when your using a standard ECU. It operates to stop components being killed.. i.e. limp mode.

Unfortunately, we can't put our foot down all the time etc, so being an adaptive ECU, it notices when we're cruising on the motorway, and helps with Economy etc.

 

[RobM]

I guess Snoopie has answered it there to be honest. When you reset the ECU you tend to drive flat out at first, just to see what the difference is. And when you do this the ECU is adapting to this aggressive style of driving.

But soon after, you go back to pottering along in rush hour, or in city driving, and the ECU starts to adapt to that, knocking back the performance slightly in favour of a smoother, more economical ride.

I'd think that if we all reset are ECU's and drove flat out all the time, they would stay that way. But since we don't, it tries to find the best mix of performance Vs smoothness/economy.

 

[Pabs]

ok - so if the ECU adapts to the "cruising" etc, why doesn't it SEEM to adapt back to aggressive mode when I put my foot down? It just seems to become more and more bogged down, until eventually I reset the ECU again....

It COULD be in my head - but soo many people say the same thing and it makes sense for it to be that way as it is adapting from scratch.

 

[RobM]

I'm not sure it continues to get more bogged down, I just think that the 'cruising' adaptations become normal to you over time and when you reset the ECU, the 'new' settings seem much stronger.

 

[DPJ]

ok - so if the ECU adapts to the "cruising" etc, why doesn't it SEEM to adapt back to aggressive mode when I put my foot down? It just seems to become more and more bogged down, until eventually I reset the ECU again....

It COULD be in my head - but soo many people say the same thing and it makes sense for it to be that way as it is adapting from scratch.

It'll probably be because of averaging, Paul.

When you start from scratch and drive flat out, it's like the result is all 9s - so the average is 9. The moment you drive slower, you're adding 5s and 3s in, so the average will now be less than 9. As time goes on the average will reduce to a 'bogged-down' average. ..... (my theory ).

 

[Pabs]

It'll probably be because of averaging, Paul.

When you start from scratch and drive flat out, it's like the result is all 9s - so the average is 9. The moment you drive slower, you're adding 5s and 3s in, so the average will now be less than 9. As time goes on the average will reduce to a 'bogged-down' average. ..... (my theory ).

so what you're saying is that if I drive "like I stole it" for a longer period of time, the average would then increase again.....

I see where you're coming from - but it just means that if I ever want to get the best out of the car - i should perform a battery reconnect.
I wonder if this would affect RR results, 1/4 mile times etc...... or if it is so minimal that it wouldn't...

 

[Nathanio]

Also like any electrical equipment that has an IPC or computer controlling it they need effectively a reboot every once in a while to clear the memory buffers and to start a fresh. You'll notice the same thing with mobiles as well. After being on for 2 weeks continuous or so they become sluggish, bluetooth may drop out etc but a quick switch on and off its soon back to normal. Same principle

 

[Pabs]

So we should all do this regularly then

Also - by clearing the error codes in VAG-COM - does this reset the ECU the same as a battery disconnect would?

 

[RobM]

No, error code clearing wont reset the ECU, it just removes any 'flags' set by the ECU to highlight potential problems.

 

[Nathanio]

I personally am gonna do a ECU reset about once a quarter or so. Takes no time at all to do and makes a big difference to the car and to the economy.

 

[mkm250680]

Bit Thick me but how do you reset ECU??

 

[RobM]

Disconnect the battery and leave it for 30 mins or so

Just make sure you have your stereo security code before you do this!

 

[Nathanio]

http://www.seatcupra.net/forums/showthread.php?t=110917 - have a read through there and all will be revealed