MTronic diagnostics / ecm failure symptoms

Skisawyer · May 16, 2019

This is awesome. Thanks for sharing.

PogoInTheWoods · May 17, 2019

av8or3 said:
Maybe some screen shots of the pictograms Ive encountered so far LOL.

Some here may be interested in the pictures but I'm much more interested in any of the extended features and functions you may discover that actually make the MDG system a true diagnostic tool for effectively troubleshooting M-tronic units by a dealer or anyone else outside an r & d lab...., and any printouts specifically determining a particular condition responsible for why a unit isn't performing as it should. I'm not yet familiar with the FI component required by those units but can't imagine it being much different than what already exists for carbureted saws..., except for the cartoons, of course. I have heard that the FI ECM stores more non-volatile information/codes which makes the system more useful for those units. Whether or not that capability will be retro'd to earlier ECMs as the MDG software evolves remains to be seen. There is talk of a next-gen MDG platform with the capability to do ECM field upgrades as new features are developed and bug fixes become available for existing ECMs. 'Course there was also the 'green' solenoid that was supposed to be a universal fix for everything, too.

I'm not trying to rain on your parade. Just stating what I have learned about the system on my own and from area dealers' experiences (and frustration) with the effectiveness (or lack thereof) inherent in the MDG system. It is what it is. And you asked.

All I know is you can buy an awful lot of solenoids for the price of an MDG system..., which is what's wrong with an M-tron saw 99% of the time when it doesn't run right anyway. Most folks don't need an MDG system to tell em that these days..., even if it could.

ABarrick · May 17, 2019

Well, replaced the solenoid, did a reset and no real change. Still has good power and is very usable, just doesn’t have that crisp, explosive acceleration it did.

I’m going to see if they’ll hook it up to the computer while I’m there with it next time I go. Dealer has a parts saw on the shelf that was damaged in shipping, so I’m gonna see if we can swap coils and see what happens. At my current rate of available hobby time, might be a month from now lol

PogoInTheWoods · May 17, 2019

Not to nit-pic, but that saw should be calibrated, not reset -- which is more than likely what you meant.

That said, your dealer should be able to do an actual factory default reset to the ECM with the MDG system which will clear out any residual weirdness present that may be causing your issue. Sorta like disconnecting your car battery to clear old codes.

Good luck with it.

av8or3 · May 17, 2019

Here’s a primer on the MDG1.
Several of the screens available to you . The sensor check is most interesting. Atmospheric pressure measured in millibars. So the saw does have an idea at what altitude it’s operating at.

av8or3 · May 17, 2019

Here’s a few more. I’ve included the top of the first two pages (of eight) of the trouble code list, and steps to take for a possible resolution. And the handy specs chart.

PogoInTheWoods · May 17, 2019

Appreciate the sharing. Definitely more info available for the FI system from the additional sensors.

friendlywithbears · May 17, 2019

Fascinating, getting very close to car tuning and diagnostics. I'd love to get my hands on one of these some day and see what can be played with. I'd also love an ms500i

ABarrick · May 17, 2019

PogoInTheWoods said:
Not to nit-pic, but that saw should be calibrated, not reset -- which is more than likely what you meant.

That said, your dealer should be able to do an actual factory default reset to the ECM with the MDG system which will clear out any residual weirdness present that may be causing your issue. Sorta like disconnecting your car battery to clear old codes.

Good luck with it.

Not to nit pic, but disconnecting your car battery doesn’t always clear your codes...and often will result in short term drivability issues as you just cleared any adaptive strategy built up in the ecm.

And yes, I “recalibrated” it not “reset” it.

RI Chevy · May 17, 2019

I'd try a new carb next if the aforementioned things do not work.

Skisawyer · May 18, 2019

ABarrick said:
Not to nit pic, but disconnecting your car battery doesn’t always clear your codes...and often will result in short term drivability issues as you just cleared any adaptive strategy built up in the ecm.

And yes, I “recalibrated” it not “reset” it.

Maybe it needs the reset followed by a calibration?

PogoInTheWoods · May 18, 2019

Precisely..., which would need to be done with the MDG setup which would be easier than swapping ECM's.

ABarrick said:
Not to nit pic, but disconnecting your car battery doesn’t always clear your codes...and often will result in short term drivability issues as you just cleared any adaptive strategy built up in the ecm.

And yes, I “recalibrated” it not “reset” it.

Gotcha. And understood regarding "adaptive strategy" in the ECM, but not all such adaptation results in desired or improved performance and can indeed be an aberration caused by any number of factors that need to be identified and corrected before the system will perform correctly again. Many systems will compensate significantly prior to initializing a trouble code, and then only intermittently in many cases. But it sounds like you already know that.

Again, good luck with it. We're certainly interested in what you come up with as the cause of the sluggish response. Be interesting to see if your dealer actually hooks it up or just gives you that other ECM to try. The dealers in my area with MDG units charge upwards of $100 to even hook it up to a non-warranty unit.

ABarrick · Jun 8, 2019

Well fellas, I think the witch hunt is over. Short version is, 462c’s don’t run like I think they should in hot weather.

Long version; Im friends with the dealer so he gave me a “parts saw” 462 to swap components to try to diagnose my problem as they don’t have the correct cable to hook it up yet. (The parts saw was a new unit that came in with the lower rear recoil mount/crankcase broken in transit. It’s new/never fueled)
I recalibrated and test ran my saw in between each part change. Swapped carbs, swapped coil, swapped flywheel, swapped decomps, air filter, etc etc. dumped my fuel, tried pump gas with husky xp oil at 40:1. Nothing made any notable difference.

Took it back to the dealer, came home with another new 462 to try. Fueled it there with his pump gas and fired it up. It certainly didn’t wow me with it’s responsiveness either. Hmm, whatever, I’ll give it a go. I noodled a tank through it last Saturday with a 2’ bar. Ran good but again, it isn’t in the same ball park as my 461 with off idle response/spool up or lean on torque. You squeeze the trigger on the 461 and it means business, the 462 is more casual. Top end/cutting speed is good. I swapped it to a 20” bar and filled it with vp this time. Ran a calibration and cut up some storm damage hackberry. Saw ran good in the cut but not as snappy off idle as the carb 462. I was switching back and forth between the two. Both running same fuel and bar/chain setups. At this point I’m thinking this is just the way they are.

To me, Mtronic doesn’t seem to like short cuts, low load or short run times or lots of throttle blipping like limbing. Neither 462c runs cleanly from a cold start until you make a few cuts with it. By cleanly, I mean they don’t accelerate well and kinda sputter and don’t have good throttle response and act like there poorly tuned. The longer the runtimes, the better they behave but as soon as the weather changes, your back to square one.

Either way, I’m done peckering around with them for now.

Orange screwdriver and unlimited coils FTW!

huskyboy · Jun 8, 2019

Can’t like that man. Hope this isn’t the norm. How’s the 572 holding up for you? Just curious.

friendlywithbears · Jun 9, 2019

I heard somewhere that mtronic takes some number of cuts from cold to calibrate itself?

I've adapted my habits with the 462 to leave the saw idling more often when I'm moving around or prepping cuts whereas before I would tend to shut it down between cuts.

ABarrick · Jun 9, 2019

huskyboy said:
Can’t like that man. Hope this isn’t the norm. How’s the 572 holding up for you? Just curious.

Not sure lol, my buddy still has it. I’m guessing he likes it.

av8or3 · Jun 10, 2019

I have an idea, try using a higher octane fuel like 93 (if you haven’t already) in the MTronic saw. The literature I’ve read says it senses “fuel quality” and that has something to do with how it runs. Don’t know how. I last used my 462c a couple weeks ago when it was 85 in the shade. I think it might have run thru my head that the saw didn’t spin up like I expected it to, but the saw cut like a beast. I really fell in love with the saw again. I had been using the 500i for the last month and that may have skewed my thinking on the throttle response. Anyway , was just thinkin’

av8or3 · Jun 10, 2019

I do remember switching over from 90 octane e-free to 93 octane e-free. I was using the 462c and there was a noticeable improvement in “that saw”. It was so different I began to wonder how it would affect my other saws.
Stihl, just thinkin’

av8or3 · Jun 10, 2019

More thinkin’
Remembering more about the last time I used the 462. That hot day, the saw started normally but died the first time I squeezed the trigger. At the time I thought it was strange. When started again it seemed to run rich for a few seconds before it settled down to a normal idle. Ran great the rest of the day. Lots of short cuts, but quite a few long cookie cutters as well. You could be right about the saw having to correct for the hotter weather though. It would make sense that it would have too , really.Air density has got to be considered when calculating air/ fuel mixture.

ABarrick · Jun 10, 2019

av8or3 said:
I have an idea, try using a higher octane fuel like 93 (if you haven’t already) in the MTronic saw. The literature I’ve read says it senses “fuel quality” and that has something to do with how it runs. Don’t know how. I last used my 462c a couple weeks ago when it was 85 in the shade. I think it might have run thru my head that the saw didn’t spin up like I expected it to, but the saw cut like a beast. I really fell in love with the saw again. I had been using the 500i for the last month and that may have skewed my thinking on the throttle response. Anyway , was just thinkin’

The VP sef I’ve been running is labeled as 94oct. Nothing available higher than that here. Not readily anyway. Most of my trigger time on these saws was in cooler weather. Thus, the first time I used it in hot, humid PA weather, I assumed something was wrong/off. Oddly enough, the carb 462 doesn’t seem as fussy as the mtronic saw to weather changes. They still cut fine, but their manners change. It lost its wow factor on the pissrev from idle lol.

MTronic diagnostics / ecm failure symptoms

chain rook

Pinnacle OPE Member

TacomaTRD98 on AS

Pinnacle OPE Member

So many saw ... so little time...

So many saw ... so little time...

Pinnacle OPE Member

a tree falling in the woods

TacomaTRD98 on AS

Mastermind Approved!

chain rook

Pinnacle OPE Member

TacomaTRD98 on AS

Sorta a husqvarna guy...

a tree falling in the woods

TacomaTRD98 on AS

So many saw ... so little time...

So many saw ... so little time...

So many saw ... so little time...

TacomaTRD98 on AS

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