AFM

DougIrby · August 6, 2017

I have a 2015 5.3 w/ max tow pkg and flex fuel.

I try to run E85 every chance I get in order to get the added power the high octane fuel provides.

I am light footed on the gas and my truck stays in V4 about 85% of the time, all the way up to 75MPH.

I have no problem with it. Most of the time I have to look at my instrument panel to see what I am running, V4 or V8.

Bxnanaz · August 6, 2017

I have no problem with it. Currently have 8,000 miles, and with 4,000 miles on this oil it's still at full mark.

B_SKY33 · August 6, 2017

Not sure how I feel about it except the exhaust system sounds noticeably different and pedal feel is different once v4 engages. Probably going to disable it

TheBlackPearl · August 6, 2017

I can't believe how many of you said that you cannot tell when V4 activates...

I've made it a game with the AFM, I can point to the DIC when V4 engages and then again when V8 engages.

Also, I've never had AFM kick in while in manual mode except when it's in 6th gear.

newdude · August 7, 2017

Did it save him any gas? I found AFM to have zero effect on mpg on my camaro after I tuned min out

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1mpg? LOL. We reset his average fuel mileage pre-tuned and post tuned, he lost 1mpg. Not a featherfoot though, went from 16mpg to 15mpg.

But in all seriousness, the car applications are the only ones where it works for longer periods of time.

ElJefeBlanco · December 8, 2017

On 8/6/2017 at 6:21 PM, TheBlackPearl said:

I can't believe how many of you said that you cannot tell when V4 activates...

I've made it a game with the AFM, I can point to the DIC when V4 engages and then again when V8 engages.

Also, I've never had AFM kick in while in manual mode except when it's in 6th gear.

I completely agree with your statement and I do the same thing.

Never screwed with the manual mode, so I'll assume that you're right there as well.

Ozer · December 8, 2017

I had the Range on for few weeks, loved how it worked and transmission felt great. Battery died while it was sitting for 3 days, i forgot to unplug the range but the battery was also old so who knows.

Didnt put range back on since and and mpg improved 1 or 2 mpg but the trans feels weird now, i can feel the converter locking and unlocking i think, its clunk clunk whenever i let off and get back on the pedal.

Range will be going back on today and staying on

Obscenejesster · December 8, 2017

I had the Range on for few weeks, loved how it worked and transmission felt great. Battery died while it was sitting for 3 days, i forgot to unplug the range but the battery was also old so who knows.
Didnt put range back on since and and mpg improved 1 or 2 mpg but the trans feels weird now, i can feel the converter locking and unlocking i think, its clunk clunk whenever i let off and get back on the pedal.
Range will be going back on today and staying on

There is a $10 switch I purchased off Amazon for my Range. I just flick the switch anytime I know my vehicle will be sitting over night.

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Donstar · December 8, 2017

I can guess when my truck will likely go to V4 mode but if I felt the transition, I'd take my truck in for service. I can't see why one would strive to defeat this feature. I believe it is possible that AFM technology may even keep the V8 viable longer.

mookdoc6 · December 8, 2017

1 minute ago, Donstar said:

I can guess when my truck will likely go to V4 mode but if I felt the transition, I'd take my truck in for service. I can't see why one would strive to defeat this feature. I believe it is possible that AFM technology may even keep the V8 viable longer.

Wait until their next one uses Variable Displacement on 2019's V-8's getting 25MPG's yeah baby!

Loco-diablo · December 8, 2017

As I've stated in prior posts. The AFM doesn't bother me a bit. I don't notice it. Whether or not it helps or hurts the engine is another matter. I have no plans to disable it or add a tuner. At least while I'm still under warranty.

Grumpy Bear · December 8, 2017

On ‎8‎/‎4‎/‎2017 at 3:28 PM, newdude said:

As long as the following parameters are met, it can go into V4 at any time. Really, the most effective points I've noticed for V4 is lower speed town and city driving. 20-50mph is where AFM will run the most from my experience with my 2012 I had. Highway speeds was where it switched in an out the most.

Where did you get this and for what motor type. LS or Ecotec3. I ask because mine is on when some of these features are out of this documents range. Thanks.

newdude · December 8, 2017

2 hours ago, Grumpy Bear said:

Where did you get this and for what motor type. LS or Ecotec3. I ask because mine is on when some of these features are out of this documents range. Thanks.

Pretty sure I pulled those from the new engine. Lemme double check for sure.

EDIT: Yep, from the Ecotec3 family. Parameters are same for V6 and V8.

Here are the AFM "denied" criteria as well:

Quote

Cylinder deactivation may be inhibited for many reasons including the following:

Engine coolant temperature out of range for cylinder activation

Engine vacuum out of range

Brake booster vacuum out of range

Transmission gear incorrect or shift in progress

Accelerator pedal out of range or rate of pedal application to fast

Engine oil pressure and temperature out of range

Engine speed out of range

Vehicle speed out of range

Minimum time in V6 mode not met

Maximum V4 mode time exceeded

Decel fuel cutoff is active

Reduced engine power is active

Torque management is active

Catalytic converter over temperature protection is active

Piston protection is active, knock detected

Cylinder deactivation solenoid driver circuit faults

Grumpy Bear · December 9, 2017

5 hours ago, newdude said:

Pretty sure I pulled those from the new engine. Lemme double check for sure.

EDIT: Yep, from the Ecotec3 family. Parameters are same for V6 and V8.

Here are the AFM "denied" criteria as well:

Mine stays enabled when oil pressure is under 25 psig and when the deceleration had the injectors shut off in cruise control. Weird. Thanks for the information. So. what tool are you using to pull that from the ECM?