Limp Mode After Flash

[braxtonslade]

I'm trying to tune a 2006 GMC Sierra 2500 6.0L. Stock truck, basic tune. Whenever I flash it, the truck goes into limp mode. Throttle is limited to 20%, but the accelerator pedal reads clear up to 160% at WOT. I've tried multiple changes, many or few, in the tune, and same result every time. I never once touched any of the throttle settings, even in torque management. The only time it goes back to running normal is when I flash the stock tune back in. Any input here? I've attached the stock tune, as well as two attempted revisions.
STOCK.hpt
87v1.0.hpt
87v1.1.hpt

[5FDP]

Limp mode will toss a code, what is that code?

Have you tried only doing small changes to see if it still does it. I mean like only adjust the power enrichment or only the timing and see if it does it. Then you can keep doing really small changes if nothing happens until it does again, then you'd know what change is making it mad.

[braxtonslade]

It doesn't throw any codes, just doesn't allow the throttle to open past 20ish percent. I've tried only changing one or two things, and it still does it, no matter what is changed. I contacted HPT support to see if maybe it was on the back end of the flash, but they don't know what could be causing it. I know it's got to do with the fact that the APP is seeing 160%, but I don't know why that would happen after only a flash.

[bigmatt89]

May not help but every time I flash my 2006 Suburban the DIC says reduced engine power and goes into limp mode. All I do to fix it is open the scanner and go to diagnostics and click clear codes before I start it and it goes away. Happens every single time.

[3strokeEngine]

Had the exact same issue on my 2005 gmc seirra 6.0 lq4 2500hd the first time I tried to flash a tune into it, reduced engine power warning message the thing would barely idle and ran all around like shit. After many cuss words and contemplating what to do next I had to do the exact same thing bigmatt described in his post. I believe its because the ECU loses communication with the electronic control module when you flash to it and somehow the communication protocol gets out of sync when the ECU boots back up and it throws the code and puts it in limp mode

[gump2388]

Same here with a 2005 escalade 6.0

[kevin87turbot]

It's a pretty common issue on 05-06 trucks. If it still doesn't cooperate after you clear the codes, just go back to the stock engine TM table and increase it by a reasonable amount instead of maxing it to 640. If it's a stock truck, you might just increase it by 40 or so over stock. That will fix it every time.