JTDowdy

2014 GMC Sierra 5.3.. AFM is switching back and forth between V8 and V4 more frequently or too much. Check engine light has come on . I havnt gotten a chance to read the code yet, but the truck seems to be running normal until the AFM starts activating. Put it in manual 5 and got it home without it switching back and forth. Keep in mind I’m on a 6 inch lift and 35s. So my Truck doesn’t drop to V4 often anyways so this is abnormal. But since the check engine light has come on my best example is at 45 with the cruise on, flat road and optimal conditions the truck will switch back and forth form v8 to v4 every 5 seconds . Anybody experienced this ?

Anybody have a workable document or link they can share? I am unable to open and could really use some more knowledge on this subject.

The only issue I've had is my leaf springs settled some and allowed my rear end to become loose. Springs weren't part of the lift but ubolts didn't have enough threads to tighten it back up. Had my shop order a different set. Didn't ask where they got them, but everything is fine now. I didn't upgrade shocks and it's a little stiff, so I'll be upgrading soon.

Currently running 35s with 6" pro comp. Anybody running 37s or have opinions on what I need to do to run 37s?