Thanks for the help! I'm 99% sure that 15% - 85% is the full range of motion for the VGT%. How often does yours sweep the vanes? How long do you have to idle before it usually does it? I'll start monitoring mine,just curious how often or at what times it should do it. I"m sure it's just because of my stock exhaust that I don't hear it.Thanks again!!

 

I don't think the vane sweep strategy was out in 2007. It was published in 2009. It is part of the engine protection features TSB, that included oil cooler efficiency, over boost, and low voltage faults. I think it is safe to say that no F-series came from the factory with vane sweep. Possibly the latest E-series could have.

Here is the TSB
http://ww2.justanswer.com/uploads/fo..._211519_A1.pdf

The TSB describes how frequently the vanes will sweep. It states that the vanes may sweep once per hour. But in my experience, while the engine is cold or partially warmed up, you may hear it more than once in the first few minutes. So I think the once per hour is only after the engine is hot and has been running for more than the first hour. Just based on my own experience. I am not straight piped, just a 4" exhaust, but I can clearly hear it when it happens. It is just a change in the exhaust tone. Yes, you can also watch it on your Edge or SG.

 

I've got a habit of using my high-idle mod when I'm warming up or if I'm idling very long at all. From a cold start I usually let it run at dead idle for maybe 1 or 2 minutes and then kick the high-idle on until I'm up above 100 deg. then I drive away. Maybe it doesn't sweep unless you're at dead idle? I'm hardly ever running at dead idle unless I'm just sitting at a stop light or in stop/go traffic or something like that. EDIT : I just read the TSB that you put up (Thanks bpounds!!) and either it's a mis-print or the vane sweep does not apply to '06 model yr. trucks. It is clearly there for the earlier yr. trucks but for '06 model yr. it lists all the other changes EXCEPT the vane sweep. If this is true that sucks because that's the only reason I paid the dealer to have the flash done,I've got my gauges to keep track of all the other stuff. Anybody else have an '06 with this flash and is yours working?

 

Yes, per the TSB, "stationary idle condition". You won't get it on high idle. I do hear it sitting in drive at a stop light.

 

Thanks again bpounds!! While you were replying to me,I was editing my previous post,I think I may have found out why I've never noticed it. Check out my edit if you don't mind. Thanks again!!

 

No, it applies. Read the TSB again, left side of second page toward the bottom.

Mine is an '06.

 

Since yours is an'06 there's the proof right there!! Sorry to be a pain,and thanks!! I understood the top of page 2 to apply to '06-'07 trucks and the bottom of page 2 to apply to E-series. Guess my comprehension skills aren't what they should be!! LOL!!

 

Maybe Matt incorporated it into the tune? Mine would do it before, but it seems to be a lot more frequently after putting the SRL+ on.

 

Mine was recently at the dealer for a turbo rebuild, the check engine light came of triggered by a low boost. I have an ESP and they said they were going to reflash the PCM to cycle the turbo. I have not heard the vanes open and close at idle, is there anyway to make sure that it was flashed?

 

I don't know of any external way to determine if it was updated. Hearing the vanes sweep would be the only clue. If you have an Edge Insight or Scangage II, you can watch the VGT solenoid duty cycle % change while they sweep. But if you can't hear it, that won't be much help. I suggest that you pick a morning when you can drive it around town from a cold start, hitting frequent stop lights, and listen closely to the engine tone. Roll your passenger side window down. That might help.

If you really think they didn't do it, take it back to the dealer and tell them you think they missed it on the work order. Be nice, and ask them if they could cable up and verify.

You can also read the strategy with certain tuners and digital gauges.

 

He did reflash my truck when i had the oil cooler replaced and egr deleted, which was 2 years ago. Ive been straight piped for over 10k miles now and this is the first time its sweeping vanes. Im not worried about i was just curious why it started doing it now

 

Thanks for the reply, I live in the country on a 55 MPH road so city driving cold is not an option, I will call the dealer on Monday, the service manager was out this week on vacation.

 

My '06 sweeps every minute or two at idle. It really freaks out Chevy guys. I tell them the Jake Brake is messed up.

 

Mine will sweep several times while I'm hooking up a trailer.

 

lol! I've had several Chevy guys ask what was "wrong" with my truck.