2009 Dragon 700, cooked my ECU :( - Snowmobile Forum: Your #1 Snowmobile Forum

dougisnow · 12-03-2012, 07:14 PM

1700 miles on my "new to me" 2009 RMK 700 Dragon 173. SLP Pipe and can, re-clutched. Lots of aftermarket vents, sled is in good shape overall...

Took it up for the season opener on Mt Adams on Sunday, 2 feet of fresh midweight powder. In comparison to the 2000 RMK 800 I rode the past 5 years, this sled handles great and the suspension and stance is awesome. It doesn’t feel quite as powerful or peppy as my old 800 but the 700 power is smooth and easy to apply. Plus I think the 163 track requires more power to turn, but keeps me afloat better. Especially after stopping or at a slower start.
so we rode about 2k up the mountain (to about 6k feet) and all of the sudden the sled died. 10 degrees and full blizzard conditions. I tried to pullstart it a few times to no avail.
I opened the hood, inspected all the fuel lines, wires (lots of them!), etc. yank a few more times and nothing. Changed sparkplugs (old one’s look fine to me), pull some more, no change. Plenty of gas. More pulls from two of us to near exhaustion, and it starts, but barely…. And I notice the gauges (rpm/temp/etc) don’t work… then white smoke comes out from under the ecu! Engine dies before I can kill it.

Nasty electrical/plastic burnt smell. by now it's getting dark and fingers are numb, but we remove the ecu cover, all harness connections look fine. Remove the ecu and WTF?! melted hot plastic/grease coming out a small hole on the bottom side of it!
Now I know I’m screwed, and thankfully I had 4 good buddies with me. Took us 3 hours to haul/tow the sled back to the parking lot.
From what I can tell, nothing looks shorted out (outside of the ecu)… I’m no electrical expert but I know plugging in a new ECU could just fry it again…
and I'd prefer to fix this myself if possible. from what i read on this and other blogs, my voltage regulator could have failed and then without that it fries the ECU? (My old RMK lost it's voltage regulator too. it was only $40 to replace, doubt I'll be so lucky this time around

...
thanks for the help, I'm anxious to get back out there asap!

**BC_Dan** · 12-03-2012, 07:56 PM

Dang, that really bites. New ECUs are over 400 bucks at the dealer, and there is likely no after-market. Regulators are spendy, too; over $140 for those. You may find one at a salvage yard such as Als Snowmobile (Al's Snowmobile Parts Warehouse - Snowmobile Parts, Snowmobile Parts, and More Snowmobile Parts) but that's hit and miss, too.

I hate electrical, especially the ECU. I would make sure all your wires are intact with nothing chaffing, especially from the ECU. It's possible the insulation was rubbed off and shorted, causing your problem. You are right, if that's the case, installing a different ECU will fry that one too. Spendy thing to do for trial and error. Sometimes you have to bite the bullet and take it to the dealer so they can hook it up to the digital equipment and do some troubleshooting that way.

Thank God for good buddies!

Outlander33 · 12-07-2012, 01:17 PM

Have the same sled as you, well, mines just an RMK, not dragon package. But! My regulator went out last ride of the season last year. Guages went out. etc etc. Called dealer from the top of the mountain to troubleshoot (that's how I figured it was the regulator) and he said do not run it or I'll fry the ECU. So I had my wife tow me off the hill... That was a fun ride...

Anyway, point of the story is yeah, if your regulator went out then it's entirely possible your ECU fried.

New regulator was $152 with shipping. Carl's Cycle Sales in Caldwell, ID said they could've gotten me a new ECU for $300. So if you can't find one in that price range you might give them a call.

dougisnow · 12-10-2012, 03:44 PM

thanks Dan and Outlander.
Made some calls to Polaris and the dealer, confirming what we all know. VR went out and cooked the ECU. wish I had stopped trying to start it, but the ECU/efi thing is new to me

soooo, Polaris won't cover it, nor will the dealer. I found a guy on ebay who had the current (better?) VR (part 4012930) for $100, it's in the mail. Also found a used (but not cooked ECU) with same throttle color (yellow), off a 2007 600 rmk.
from all my research and chat with the dealer, it should work as original, just needs to be reflashed for appx $50. or does it need reflashing? anyone know?
also i'm not replacing the capacitor (4011114), but should I? (another $75).
I don't want to get stuck in another blizzard and have more electrical issues! scary stuff.

**RJ Gleason** · 12-11-2012, 12:25 AM

I would reflash it, the newer map is better.

mat · 12-11-2012, 03:09 AM

Cool story, but without a nice ending

sometimes sledding just sucks lol

dougisnow · 12-11-2012, 05:44 PM

yep, I talked to the dealer (SK Northwest), they said a fresh reflash is necessary... i'm going to put on all the new parts -- capacitator, voltage reg, and ecu -- muscle it onto my trailer and take it to them... fingers crossed, hope i get out of the woods with this prob and into the woods with a reliable sled. I'm a fan of polaris, but they dropped a few notches with this VR issue...