- Scotty, I have a 2008 GMC Sierra 1500 z71 slt with the 5.3 vortec v8, 169000 miles. It has the active fuel management on it and I absolutely hate when it goes into 4 cylinder mode, while towing. What do you think about something like a range obd2 arm disabler? Thanks.
For the electronic bypass, I recommend using the AFM disabler from Range Technology: Check to make sure your year/model truck is supported.
https://www.rangetechnology.com
I would buy from them direct to get the most recent firmware. These also won’t drain your battery which other AFM disablers can.
All you are doing is disable via software (not the hardware which can still cause problems but at least it doesn’t go from V8 to V4 which exacerbates the issues), but to truly get rid of AFM for good you also want to remove/swap the hardware which can still fail on you; you have to have a shop delete it by replacing the lifters and cam (and then tuning out). It’s about $3,000 or so.
But if you don’t want to spend the $3,000, you can use that disabler above - still better than nothing.
I've heard that shifting to 3rd gear locks out AFM, but can't verify.
