No throttle response 06 Chevy Silverado 2wd 5.3

[Benjaminngarcia]

It is a 06 Chevy Silverado all stock except cold air intake and a sound system. I recently upgraded the cooling system to the electric fans that come stock in some models. Upon tuning the ecm to turn on the Efans they work great but now I have a battery light on and I don’t have any check engine lights. The real problem here is that when I start the truck I can give it throttle for like 5 seconds but once rpm’s drop under 1k I lose throttle response. I can put truck into gear but again no response but can move with foot off break. Again no check engine light but I’m assuming it’s because of all my accessories like the Efans, sound system, led lights. Need help on fixing.

 

[zora]

With all these increased electrical loads, what did you do about alternator amperage?
How exactly did you "tune" the ecm?