TBW Cuts Out When Speed Shifting?
Club Member
Joined: Aug 2007
Posts: 10,393
Likes: 2,060
From: N. Atlanta Burbs
There's such a thing called "Power management" in the ECM.
Little things such as... If the ECM thinks the motor is too hot it won't just to into EITMS it will go into "Limp Mode" and only give you enough RPM's to make it to the curb.
There is also something called "Throttle Blade Control". If you snap the throttle to WOT at certain lower RPM's the ECM will not allow the throttle body to open up to 100%. Such as... 100% throttle snap at 1750 RPM's = 55% throttle, 2000 RPM's = 71.4% throttle. See attached picture.
So... it may not be the Power Commander.
-wiz
Little things such as... If the ECM thinks the motor is too hot it won't just to into EITMS it will go into "Limp Mode" and only give you enough RPM's to make it to the curb.
There is also something called "Throttle Blade Control". If you snap the throttle to WOT at certain lower RPM's the ECM will not allow the throttle body to open up to 100%. Such as... 100% throttle snap at 1750 RPM's = 55% throttle, 2000 RPM's = 71.4% throttle. See attached picture.
So... it may not be the Power Commander.
-wiz
Grand HDF Member
Joined: Dec 2007
Posts: 4,999
Likes: 55
From: Bay Area
I asked this question a while back. I questioned Jamie at FuelMoto about my map. I was shifting hard at redline. Turns out that the ECM detects a high rev situation with the clutch in or in neutral it mometarily shuts down the motor. Thats why it feels like you hit the kill switch and then it takes off again.
Outstanding HDF Member
Joined: Jun 2008
Posts: 2,132
Likes: 25
From: NorCal
If it's an HD thing, then why hasn't it happened to me?
Runaway throttle? I tried speed shifting once, holding the throttle wide open. Heard a lot of valve train rattle, but the bike never let up. I ride my bike pretty hard, and have never had my throttle cut out like on my two buddies' bikes that have PCV's.
Maybe it is a HD ECM thing, but it's never happened to my bike, or any other bike I've ridden without a Power Commander. Only two bikes I've ridden have done it, and they're both '09 Harleys with PCV's.
Go figure.
Runaway throttle? I tried speed shifting once, holding the throttle wide open. Heard a lot of valve train rattle, but the bike never let up. I ride my bike pretty hard, and have never had my throttle cut out like on my two buddies' bikes that have PCV's.
Maybe it is a HD ECM thing, but it's never happened to my bike, or any other bike I've ridden without a Power Commander. Only two bikes I've ridden have done it, and they're both '09 Harleys with PCV's.
Go figure.
Intermediate
Joined: Apr 2007
Posts: 38
Likes: 0
I know I'm digging up an old post, but yesterday my bike, while being picked on by a BMW and I went to show him(Embarrass myself) whos boss, JUST QUIT!!!! I shifted to 2nd really hard and fast but I did roll out of the throttle really quick. It lunged when going to 2nd then just died!!!! WTH!!??? All the way to the shoulder I go, with the Beemer blowing past (Whatever he'd already been roasted.) I mean it was like I bumped the on/off switch to off and didn't know it. But that wasn't it. I turned the main switch off, waited a few seconds, turned it on, and vrrooom, everything is fine. Really? What could cause this? A few weeks ago, hard acceleration the same way it pretty much went to one cylinder for about 10 seconds then cleared up. I checked and did have p codes 0131, 0134, 0031,1353,1356,0151,0154, but most are due to my o2 sensors being dis connected for the PC V. Anyone have any ideas? Fuel Moto Map, PCV , A-Ness Big Sucker, V&H 2into1. Police 2010 103 FLHTP.
Road Master
Joined: Feb 2009
Posts: 766
Likes: 6
From: South Dakota
I've had the same thing happen quite a few times. Once it was deader than a doornail. Like a previous post, to the shoulder, turn off and back on then it was fine. Other times it's an eye opener. Fighting the g's holding on then all of the sudden trying not to eat the fairing. I've always attributed it to the rev limiter but I don't think that's the case. I know when the tach stops moving (rev extend enabled on PCV) to shift. I've got quite a few rpm's left before actually hitting the rev limiter at 6200 then. The 255's cams aren't doing me any good up there anyways.
It has to be some kind of ECM thing telling it to shut down. Usually it's 2-3 seconds of no power, like the kill switch was flipped, before I regain throttle.
It has to be some kind of ECM thing telling it to shut down. Usually it's 2-3 seconds of no power, like the kill switch was flipped, before I regain throttle.
Club Member
Joined: Aug 2007
Posts: 10,393
Likes: 2,060
From: N. Atlanta Burbs
See above where I posted about Power Management?
I can't prove this so act like it is third party information, (NWaS)
If the ECM sees rapid acceleration for a preset amount of time including what could be explained as drag racing near or at the limiter, the newer ECM's will go into this Power Management and shut the bike down. What year started this I don't know.
Was told it was like the ECM on my high torque truck. If it senses speeds at or over 100 MPH it shuts down and locks out the ignition for 10 minutes. The techs call it "run proof". You can't run from a LEO and your kid can't tear up your truck.
Now again, I can't prove this and I've pushed some envelopes pretty hard to get details but no one seems to either have any or want to talk about it.
This may be true or it could be BULL SHUCKS... don't know. All I understand is there is more of this "run proof" popping up now a days.
I can't prove this so act like it is third party information, (NWaS)
If the ECM sees rapid acceleration for a preset amount of time including what could be explained as drag racing near or at the limiter, the newer ECM's will go into this Power Management and shut the bike down. What year started this I don't know.
Was told it was like the ECM on my high torque truck. If it senses speeds at or over 100 MPH it shuts down and locks out the ignition for 10 minutes. The techs call it "run proof". You can't run from a LEO and your kid can't tear up your truck.
Now again, I can't prove this and I've pushed some envelopes pretty hard to get details but no one seems to either have any or want to talk about it.
This may be true or it could be BULL SHUCKS... don't know. All I understand is there is more of this "run proof" popping up now a days.
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Road Warrior
Joined: Mar 2008
Posts: 1,783
Likes: 10
From: Oh
My 08' SG with a PC-V did the same thing. I ride with some HD mechanics sometimes and they all told me the same thing, something about the PC-V. They also have the issue with the tach not going above 5K. I now run a SEPST in my 10' RKC and have not experienced this, you tell me. I will probably never use a piggyback fuel mangement system again, too many issues. Very happy with the SEPST.
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