Ducati Monster Forum

Moto Board => Tech => Topic started by: el_loco on June 13, 2010, 08:56:01 AM

Title: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 13, 2010, 08:56:01 AM
And why would I want to do that?  I've been trolling through archives trying to find clues to the cause of my intermittent 4k rpm hiccup, and I came across a thread where it was suggested that a guy disconnect his neg terminal to reset the ECU, possibly as a fix for a 5-6k RPM hiccup. 

Is it around 4k RPM that the ECU switches data readings to determine fuel/air?  I'm wondering if my ECU is farting during this switch up, causing the intermittent burp at around 4k when the engine is warm?

2002 M720 Senna, 8033 miles and counting...
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: erichan8757 on June 13, 2010, 09:58:50 AM
not likely, if that's valid, both of my ducs would have been coughing to death already

!! however not entirely sure of Stock ecu unless there's difference btw stock and DP
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: ducpainter on June 13, 2010, 10:59:08 AM
The closed loop systems change around there I think with lots of throttle.

Your bike wouldn't be affected because it has no O2 sensor.

In automotive applications you can clear fault codes by disconnecting the battery.
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 13, 2010, 02:51:13 PM
My bike wouldn't be effected by the ECU or by the neg. terminal disconnect?
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: erichan8757 on June 13, 2010, 03:07:11 PM
Quote from: el_loco on June 13, 2010, 02:51:13 PM
My bike wouldn't be effected by the ECU or by the neg. terminal disconnect?

yup ! that's basically what the mighty painter was saying:0

so you may have to find where the problem is!
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: ducpainter on June 13, 2010, 03:25:31 PM
Quote from: el_loco on June 13, 2010, 02:51:13 PM
My bike wouldn't be effected by the ECU or by the neg. terminal disconnect?

Quote from: erichan8757 on June 13, 2010, 03:07:11 PM
yup ! that's basically what the mighty painter was saying:0

so you may have to find where the problem is!
The ecu won't lose any problem by disconnecting the battery.

Your bike has no lambda sensor so nothing changes in the mapping due to the way it reads data. Your ecu is not that sophisticated.

If you have a hiccup at 4K rpm you have a basic set up or map issue.
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 13, 2010, 03:50:26 PM
Quote from: erichan8757 on June 13, 2010, 03:07:11 PM
yup ! that's basically what the mighty painter was saying:0

so you may have to find where the problem is!

And if it's a basic set-up or map issue, it'll be dealership time, right?  I'm leaning toward map, because it has no hiccup until temp reads over 200 degrees, and I rode it for awhile before it started doing this, though when it started it was abrupt.  Any guesses or anything easy I should check?
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: ducpainter on June 13, 2010, 03:56:56 PM
Quote from: el_loco on June 13, 2010, 03:50:26 PM
And if it's a basic set-up or map issue, it'll be dealership time, right?  I'm leaning toward map, because it has no hiccup until temp reads over 200 degrees, and I rode it for awhile before it started doing this, though when it started it was abrupt.  Any guesses or anything easy I should check?
The only two sensors that read temp on your bike are the ambient air and engine temp. You could check the connectors.

A good independent tech can handle set up issues. If you have a stock or DP ecu all that can be adjusted is trim. If you have an FIM flashload they can be adjusted for each zone in the map independently.
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 13, 2010, 06:57:50 PM
Quote from: ducpainter on June 13, 2010, 03:56:56 PM
The only two sensors that read temp on your bike are the ambient air and engine temp. You could check the connectors.

Ambient air behind the headlight, engine temp on the cylinder or the oil temp sensor near the drain plug?

A good independent tech can handle set up issues. If you have a stock or DP ecu all that can be adjusted is trim. If you have an FIM flashload they can be adjusted for each zone in the map independently.

I'd bet I'm running stock ECU, what is the DP that folks use, what does the DP stand for (pardon my ignorance)?  And "Trim" meaning the static air/fuel ratio as opposed to a variable one?
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: brad black on June 13, 2010, 08:00:34 PM
the 2002 was the only injected m750 and there's no dp ecu for it akaik.

if it was ok and suddenly went bad, i'd change the fuel filter first then take it to someone who can watch what the sensors are reading as it warms up to see if any are off.

usually ok when cold and bad when hot is too lean.
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 13, 2010, 08:36:20 PM
Funny thing is that it's backfiring a little when cold, and popping on decel which it didn't do originally but that had me thinking it was running rich. It's running strong, but still definately somethings changed about it's character through different RPM's
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: ducpainter on June 14, 2010, 01:06:26 AM
Quote from: el_loco on June 13, 2010, 06:57:50 PM
I'd bet I'm running stock ECU, what is the DP that folks use, what does the DP stand for (pardon my ignorance)?  And "Trim" meaning the static air/fuel ratio as opposed to a variable one?
DP=Ducati Performance, but if Brad doesn't think one was available he's probably right.

Get the idea out of your head that your ecu will vary anything from it's normal settings. It's a very basic PROM. Trim is an adjustment, in percentage, to the map. So if your bike is lean you can adjust the map say 10% throughout the entire map...whether it needs it or not everywhere.
Title: Re: Does disconnecting the Neg. battery terminal REALLY reset the ECU?
Post by: el_loco on June 14, 2010, 05:15:00 AM
Got it.  That is what I meant by static v.s variable.  Static trim meaning change it an amount which stays the same across the entire map, variable being a dynamic response change, which sounds like what the DP does.  But no DP ECU for my bike means no upgrade for me.