Afm?

wzschirnt · January 11, 2011

I'm new to this forum and have learned some stuff already. I have a 2007 1500 with the VortecMax package.

Question:

When people say "AFM", is that the 8 cyl to 4 cyl change when at light throttle? That "feature" is the most annoying thing to me while driving. Since I have an after-market exhaust, the change between 4-8 sounds awful (like a "jake-brake on a diesel). Do any of the tuners - BlackBear, etc - take that 4-8 cyl swap out?

Thanks.

walt

Stevens03 · January 11, 2011

Welcome to the site. Yes, AFM is active (oops edit) fuel management, and switches between 8cyl to 4cyl. For me, it did nothing. I had a diablo tuner and was able to turn it off. I ran a test and saw no mileage difference on or off. So in the end, I left it off.

After playing with diablo,.. and it did make a nice improvement once dialed in,... I got blackbear for my 07 Vmax. Big difference. IF you choose to go that route, what worked nice for me was having him tune for 91 octane, removing all the TQ management out of the engine and trans for regular driving, and left the TQ management alone in the tow/haul mode. And let him just make his magic happen with the transmission shift points. He does a nice job. I assure you, your truck will feel and drive like a different truck.

And yes, he can turn off the AFM.

jdubub · January 11, 2011

Welcome to the site. Yes, AFM is automatic fuel management, and switches between 8cyl to 4cyl. For me, it did nothing. I had a diablo tuner and was able to turn it off. I ran a test and saw no mileage difference on or off. So in the end, I left it off.

After playing with diablo,.. and it did make a nice improvement once dialed in,... I got blackbear for my 07 Vmax. Big difference. IF you choose to go that route, what worked nice for me was having him tune for 91 octane, removing all the TQ management out of the engine and trans for regular driving, and left the TQ management alone in the tow/haul mode. And let him just make his magic happen with the transmission shift points. He does a nice job. I assure you, your truck will feel and drive like a different truck.

And yes, he can turn off the AFM.

+1

700 sportsman · January 11, 2011

I agree, if yo go with a blackbear tune, you won't be disappointed. In some cases peoples mileage even goes up whe shutting off afm

txab · January 11, 2011

AFM = POS

oldschool327 · January 11, 2011

AFM= Active Fuel Management

wzschirnt · January 11, 2011

Ok. Thanks for the replies. Trans acts "stupid" sometimes - seems to grab 1st gear when 2nd would do just fine in slow corners or rolling a stop sign with light throttle or hangs between 1st and 2nd before making up it's mind. GM says "no problem". I have the extended warranty, just in case!

Hopefully, new program will fix that.

Thanks again.

walt