Resetting the ECUs- Don't forget!

I think you guys got it all wrong and Brian all wrong. I can't get in his head but I am sure he feels there is value in an ecu reset. I think the tinfoil hat thing was really in referrence to Roberts voodoo isssue below.

<<You are right on the 2.7 but some what wrong on the 2.5. Here is the kick ... My ECU's are 2.5 and it takes at least 200 miles to re-learn with seasons changing and so temperature / humidity. I drive my car an average of 100 miles a month and so it would take half summer .... and for the time is done the season changes again. Instead takes 10 minutes to re-learn and be done with it. I got this info from an old italian friend of mine, now retired, that used to work at the factory in Maranello and knows ... >>

About 100 years ago I learned the value of an ecu reset in a 348. If I disconnected the battery/reconnected and immediately drove the car it would do weird things like stall at the stop sign and idle funny and generally just run poorly. No other electronic car of its day was so "sensitive" to this relearn of the "learned block memory". I chalked it up to another stupid ferrari trick. But it was a "must do" when the battery was disconnected. My car would not learn on its own by just driving it around if i did not follow THE proceedure. Since that time I have always followed a similar protocol anytime I disconnected a ferrari battery and have been rewarded by very good running cars. I don't like bosch anymore than the next guy but I am learning to have more and more respect for the power they have put into these motronic systems. I do not think there is any value in an ecu rest just for the heck of it. But there are enough times where I need to swap out a battery, dink with the stereo, weld something where the battery needs to be disconnected. When that happens the reset procedure is very important.

Oh and you guys would do well to have good strong batteries and keep them on tenders if not driving the cars. Many of the wonky electrical issues start by having a week battery. As cars have gotten more electronic and obd more sofisticated power is everything! A charged battery should read 12.65 V. At 12.45V it now only had 75% charge and at 12.24 it only had 50% charge!!!! So when you use lots of amps starting the car run the a/c and turn on the boom box is it no wonder you get wonky electronics with bad connectors that just add more resistance into the circuitry?

 

Resetting the ECU's will only make the car run "great" in open loop mode, until it goes into closed loop, and start RE-LEARNING and correcting the fuel trim because all the things that were wrong with the car before ( leaking headers, high leakdown, unbalanced throttle bodies, bad 02's and MAF's, etc). There is no magic cure, is only a matter of a couple of days and everyhting will be back to "normal"

Fernando

 

FERNANDO ---

THANK YOU !!! YOU GET IT

I get tired sometimes of arguing Engineering principles with lay people --- just as my Attorneys & Physicians get tired of me arguing Law & Medicine with them...

For all those who truly believe that "resetting an ECU" will fix anything, I strongly urge you to call up Bosch Technical Support (the architects of the ECU's we're all talking about here), and ask them to explain it to you ---- I give up....

.....no offense folks....I believe everyone on this forum has something to offer all of us ---- but, we all have limitations on what type of expertise we have.

 

I second the notion that a sub par battery makes these cars do funny things. I think one of the reasons my car has NEVER given me a CEL since the day I got it home (5 years and 6k miles ago) is keeping the battery charged and or replaced as needed

 

Oh come on dude .... Voodoo ?

 

After I purchased my car over 2 years ago, I had constant problems with CEL's and car running weird. So I thoroughly cleaned all the contacts and did a reset and never had a single problem after, so to me was a good thing. I agree with you and Bryan and everybody else that if you have a real problem that can not be cured by contact issues, the reset will only work for short time. Hopefully this will end our "family feud"

 

Very good Ernie. I read this many years ago and the other day when I mentioned what was said on here by some "great mechanic" to some really knowledgable Ferrari Mechanics, they almost fell on the floor laughing.

 

Sorry I'm a little dense. Does that mean they believe in resetting learned block memory or they think it is bunk?

 

I can attest to this - I had my Maserati serviced before it got shipped to me... in the process they (probably/likely) disconnected the battery; it took me two tries to get all the sensors to come back online... first time I went, I had put about 100 miles on it... all but two of the sensors had come back online by that time... they said: "go drive it for another hundred miles or so - do a combination of stop & go and freeway driving, then bring it back" - that worked; all sensors were fine & back online after that.

 

At themselves?

 

this is funny stuff

and

don't forget to set your clocks back , , they work better !

 

They do reset them. Its funny to think that they may be wrong as some of them are connected to those who originally created the mapping for these ECUs for Ferrari.

 

I definitely need to get me one of those hats! BTW, any after market chip tuner will tell you to do this to reset your ECUs after an upgrade and I am pretty sure I did not see them wearing tin foil, but they could have hidden them under their caps just to keep me guessing.

 

Car would not idle on it's own this morning. Cranked at least 10 times and forced gas but would not idle. Disconnected the battery for 10 min. reconnected, restarted and bam...all is back to normal. Drove it for 50 miles breaking in new tires, got gas, stopped at the scooter store, etc. No issues with idle...so is this really a placebo or not?

 

What do you think?

Better get your tin foil hat ready like the rest of us.

 

Resurrection of an old thread....

 

I reckon a whole bunch of us will be doing it today
Sometimes when I put it in neutral when coming to a stop my revs are sometimes delayed and I have to touch the accelerator slightly to help the engine go back down to idle speed. I wonder if this reset will fix it as it relates to reading the accelerator potentiometer position on start up as mentioned by Ernie in his previous post with attached pages from the handbook stating this fact.
Worth a try.

 

I reckon another bunch of us won't.

 

How about using the diagnostic port to reset the ecu and actually identify all the voo doo and idle spook issues that the ecu will have stored by way of dtcs? The battery disconnect wont clear stored codes for real faults. Connect to diag machine,record codes,clear codes and repeat.
order replacement parts,actually fix car and now enjoy a real result!

 

I would say that if you believe doing an ECU reset works then just carry on doing it as you're not going to hurt anything by doing it and you'll have your own peace of mind in the process.

If you don't believe that doing an ECU reset works then fine, don't bother with it and you too will have your own peace of mind.

For those who are not sure about the subject (new owners for example), give the ECU reset a go and make up your own mind if you think it works or not (As I say, you're not going to hurt anything trying it and it will only cost you @ 10 minutes of your time).

Those of you who think an ECU reset does nothing at all: Are the people who do the reset causing any problems to the car in anyway? - They're not are they?, so there's no real need to ridicule them. If it helps them enjoy their car even more then great, and if the reality is that it's a waste of time: Hey! - It's only a waste of 10 minutes or so. That's hardly the end of the World is it?

This exact same same argument goes on with BMW's. Some swear an ECU reset works, whilst others swear blind it does nothing at all, but no one can come up with definitive proof either way.

(I note that some in this old thread have suggested contacting Bosch to find out the truth of the matter [suggesting that Bosch will simply laugh in their faces!], but I notice these same people suggesting contacting Bosch never bothered to do it themselves to prove beyond doubt that they are right!).

This whole subject is one of those that will never be resolved (along with when to change the timing belt/belts on a Ferrari, or the best/proper way to warm the car up from cold, the best/proper way to bed new brake pads in, inflating tyres with Nitrogen rather than air, etc., etc.), it will just run and run, with everyone having their own opinion on the matter.

So long as they're not damaging the car, does it really matter if some people do it and others do not? - I don't think so!

 

I have never "needed" to perform the reset of the parameters on my 2.7 F355...

But my 348 2.7 had various little gremlins such as rough idle, stalling when coming to a stop - little things that would pop up on occasion.

And on occasion, I would switch the battery off, and the problems would be solved for a very good length of time if not permanently. Such as the air conditioning error code I will reference ahead - I never ever saw that code again.

Even my 599 would decide sometimes not to give power to my radio, and the radio wouldn't work. Boom - the battery trick would solve that electrical problem.

Naturally, this is the layman's way of quickly resolving an issue at home, and proper mechanical repair and diagnosis is the real way to solve the problems. But the reset *can* "resolve" issues sometimes - this is a fact. I even posted a thread about this many, many moons ago when I was an F-Chat infant.
http://www.ferrarichat.com/forum/ferrari-discussion-not-model-specific-sponsored-algar-ferrari/38791-i-love-turning-battery-off-has-trick-ever-solved-your-problem.html

And wouldn't you know, Brian gave us his thoughts on the matter even back then. Thank you Rifledriver. As he suggests, the reset of the parameters will not make a sick engine healthy again. However I can testify that it can mask certain small problems or make them go away for a good length of time. The readiness codes will be cleared, so watch out if vehicle inspection is needed.

 

Well said Phil.

I personally don't bother to 'routinely' reset my 2.7 ECU's, only if I have a problem with rough running.

 

I haven't tried an ECU reset on My 348, but I did once try it on My E36 BMW.

For a couple of days the car did seem to run a bit crisper on acceleration, but I couldn't guarantee that that wasn't just the famous placebo effect.

After that first couple of days though, the car felt exactly as it had done previously. I figured that either I'd got used to the new, reset settings, or the ECU had reverted back to its previous settings to suit My driving style.

It would be interesting to hear what a Bosch engineer would have to say about ECU resets.

 

Since this has been resurrected, allow me to add some insight I've picked up since this was originally written. I'll include some sources and facts, along with my analysis, and make the case that after all these years ...

... both sides of the discussion are right.

While the exact inner workings of the Ferrari-specific Motronic aren't highly documented for the general public, based on the information provided in the workshop manual, Bosch service manuals, and the general information about this era ECUs:

1. Resetting the ECU can affect the engine.
2. The impact of the reset will vary based on other factors, mentioned below.
3. It is very likely that substantial driving will achieve the same affect as an ECU reset, assuming certain conditions are met.

Both the 2.5 and 2.7 feature a patented Bosch technology called Adaptive Lambda Regulation. This uses an additive value to compensate for fuel mixture (Lambda) issues that can be caused by any number of actual problems (leaking gaskets, dripping injector, low fuel pressure) or malfunctioning sensors (fouled O2, loose wire, bad ground).

The ECU uses a combination of lookup tables and sensor data to attempt to regulate the Lambda. In addition, the Adaptive Lambda Regulation provides a "permanently stored" (348 Workshop Manual C49) value to compensate for normal aging or other issues, up to a +/1 20% of ideal Lambda.

Further, the Ferrari Workshop Manual specifically states "Note: Since the operating statuses of the engine are permanently stored, the connection between the ECU and the positive terminal of the battery much not be interrupted. ... Should this, nevertheless, occur, the ECU must be given the opportunity to once again store in its memory the data relating to the operating statuses of the engine. For this purpose, it is enough to simply drive the car several kilometres at partial load." (348 Workshop Manual C49)

While I don't have a source handy, I seem to recall that the sampling rate for this additive adjustment was performed infrequently, perhaps once every 10 minutes? Source needed here.

So based on the WSM, the explanation of the Bosch patent, and the clear inclusion of "Adaptive Lambda Regulation" errors on the 2.7, I think it is logical to say that the ECU does, in fact, store permanent adaptive data to NVRAM and that "resetting" the ECU has a clear and documented effect.

So let's consider why this might matter to some people, and not to others.

Recently, I had a major performed on my car from an excellent independent in my area. My car ran great after returning, but I was plagued with an intermittent 1211/1212 error. If you are familiar with this issue (Lambda Regulation), you know it can be difficult to isolate unless you have access to exhaust gas analyzers, or other methods to quickly determine whether you are lean/rich, and why. In my case, I could reset my ECU, my car would run fine for weeks, but then the CEL would appear again. Even with the CEL on, my car never felt underpowered, and would often idle fine.

I'm intentionally making this next part non-technical, so I'll avoid the use of open/closed loop.

Our ECUs are designed to use a default programming at many phases of normal driving. In these periods, such as when the car is first started, or when you are at full throttle, the ECU ignores most sensor data and uses a default. In these cases, assuming your engine is fundamentally running properly, it should perform well regardless of any sensor problems.

Where the sensors really come into play is for emissions and day to day driving. It is during this period that your Additive Lambda Regulation value is tweaked, and your ECU begins to try and compensate for any issues (real or bad sensor) that is sees.

So to understand why a reset may help, let's consider the following situation:

1. You have a car back from a fresh major, clean bill of health.
2. You have a flaky sensor that occasionally goes south, and causes the Lambda regulation to become more aggressive as it tries to compensate for an issue that isn't actually there.
3. One side of your engine goes full-tilt up to 20% away from ideal, before giving up and tossing a CEL.

In this case, your ECU is causing your issue by improperly tweaking the Lambda, when it isn't needed. Resetting the ECU would reset the Adaptive values back to default, which will almost certainly be closer to the correct value for a properly running car. The car will run and idle better, and remain this way until the adaptive regulation slowly starts to adjust out of range again.

In contrast, consider a situation where a vehicle DOES have a legitimate issue with fuel or air. In this case, if the problem is within the 20% Lambda range that the ECU can adjust for, and the ECU has had enough time to adjust the adaptive value to the ideal amount, resetting the ECU would undo that compensation, and likely cause the engine to run worse.

The first situation was actual, and what I encountered. My problem ended up being a bad MAF. The second situation is hypothetical, but I think is a plausible scenario.

Over time, and given enough driving in the range where the ECU uses sensor data, I suspect a properly functioning engine would adjust the adaptive values properly back to where they would need to be, even without a reset. The advantage of the reset is that it expedites the process, and in cases where you have a bad sensor, it may simply buy you some time until the adaptive value becomes a major contributor to engine performance again.

So in summary, my position is that resetting the ECU is definitely not a placebo effect, and can immediately improve issues with some vehicles in some cases. This is particularly true with cars plagued by electrical connection problems from loose and crumbling Amphenol plugs / sockets, which is fairly common.

HOWEVER, I will add that any improvement (or change whatsoever) created by a reset is very likely due only to resetting the Lambda Regulation back to baseline, and is a temporary and compensatory fix for some other underlying issue.

As someone with experience in 1970/80's electronics repair, I certainly wouldn't rule out the possibility of occasional ROM or RAM issues, failing passive components, or other common Microcontroller glitches coming into play for some cases, but I think the Lambda Regulation is the main player here.

As always, if there is anything I goofed on, or if you have a better or contradictory source, it is always welcomed. I don't post here for my ego, I do so in hopes that I can contribute some back to the community, and continue learning.

 

Excellent write up, makes sense to me. Thanks!