Range Technology AFM Disabler

[Sierra048]

Can someone help explain how the AFM on my Sierra pick up (the V6, not the V8) can be affected by going up hills. Most aren't extremely steep, but gradual inclines. The truck seems to lag once it starts to begin the incline before it slowly starts to built up momentum. I can be doing 65-70 mph on level ground and start going up a not so steep hill and the lagging/down shifting becomes noticable. Going from 4 cylinders to six? Not sure if its the transmission shifting to a lower gear, or maybe the AFM functioning. I honestly don't know. I was researching the Range Technology AFM disabler and was wondering if this might be a solution by giving me all six cylinders all the time? I'm not sure I explained or described it very well so please ask for clarifications if you need.

I've had smaller six cylinder engines with less hp that didn't act like this. Just a little frustrating. Thanks.

 

[SteveSRT8]

please consider a canned tune, available from several different suppliers. It will do much more than simply alter AFM operation. You will love it.

That's a great engine suffering from extremely poor shift programming and TC strategy. Proper shifting sooner, better TC application, and some minor adjustments here and there will really wake that truck up. Far more than simply disabling AFM only...

 

[AZjeff]

I have the same 4.3 in my '16. I don't think the AFM is causing what you feel, if I watch the 4/6 display it shifts back to 6 seamlessly with the slightest touch of the throttle or load on the engine. I think it's the shift programming (including torque converter) that wants it in the highest gear/lowest rpm for mileage. Mine drops a few mph then double shifts to 4th to pick up some speed then back to 5th. Over the top then back to 6th then to 4cyl. It doesn't spend much time in 4c mode. The double downshift is a little annoying but my '06 5.3 Sierra did the same thing with the 4L60E so it's nothing new. They say in the silverado/sierra forums if you turn off the hill holder function the shifting is better, I haven't felt any difference. One thing to note with the RT unit, if you leave it plugged in it does have a small drain on the battery apparently. Not messing with anything until warranty is up.

 

[CKN]

Originally Posted By: SteveSRT8
please consider a canned tune, available from several different suppliers. It will do much more than simply alter AFM operation. You will love it.

That's a great engine suffering from extremely poor shift programming and TC strategy. Proper shifting sooner, better TC application, and some minor adjustments here and there will really wake that truck up. Far more than simply disabling AFM only...



This will leave a "change event" on your ECM-even if you revert to the stock tune when visiting the dealer. It's not a big deal UNLESS you need warranty work on anything power train related.

They have the option of voiding your warranty.

The Range Device does not alter your ECM. It controls the AFM through sending signals through the circuits.

 

[ls1mike]

If you don't want to mess with your ECM the Range Device does a very good job of disabling the AFM. I have one in the Caprice.
It does not leave a change event. You can unplug and it is like it was never there.

 

[OLEJOE]

I have the Range Technology device installed in my wife's 2011 5.3 Tahoe and it works great. I found that running with the transmission in M5 worked also. Actually prefer running in M5. It increases the rpm but doesn't decrease fuel mileage like you would think. At higher rpm, it takes significantly less amount of throttle to achieve the same amount of power and improves drivability enormously. With transmission in M5 the AFM is disabled.

 

[CKN]

Originally Posted By: OLEJOE
I have the Range Technology device installed in my wife's 2011 5.3 Tahoe and it works great. I found that running with the transmission in M5 worked also. Actually prefer running in M5. It increases the rpm but doesn't decrease fuel mileage like you would think. At higher rpm, it takes significantly less amount of throttle to achieve the same amount of power and improves drivability enormously. With transmission in M5 the AFM is disabled.



Yes-this is what I do instead of the range device. Works ideal for around town. On road trips I do put the selector in "Drive" and let the AFM do it's thing-which isn't noticeable IMHO on the highway.

 

[SteveSRT8]

The reason for the throttle being far less with AFM disabled is due to the incredibly different opening required when you reduce the displacement of the engine. AFM is virtually seamless, nearly as good as in our 2014 Hemi.

And I have yet to really see any stealership even begin to look for any changes in the ECM unless there is serious engine damages. About as likely as getting struck by lightning. Once you are past a few thousand miles and are certain of the reliability of your new truck a competent company like Diablosport can tune that thing so beautifully you'll never go back. I've had their canned tune with minor tweaks on my sig car for 5 or 6 years now with no issues at all. And for a small fee you can get their techs to customize your tune by sending them back and forth by the Net. Super easy.

This guy needs transmission help, all the AFM disabling in the world is unlikely to help the problem he describes

 

[Sierra048]

I've read the replies three times. I'm getting the impression that what I descibed isn't due to the AFM system. Is it more associated with the transmission programming?

Azjeff, how do you monitor the change between four and six cyliners. I don't think my display has that function. Your truck is two years newer so maybe they upgraded the display. Or did you have to buy an upgraded display?


SteveSRT8, I appreciate your suggestion on the tune. Maybe a little over-cautious but I just don't trust dealerships and don't want any excuse to deny warranty coverage if a custom tune left a footprint, even though not responsible. Out of warranty, I would certainly consider it.

OLEJOE & CKN, I learned how to drive on a manual transmission, but this is the first vehicle I've owned that has both capabilities. Short of using M1 to get up two short hills to reach our home, I've not used the manual capabilities. Can you please describe how you use M5. Do you have to go through all manual gears to get to M5 or can you just select M5 after being in auto mode?

To everyone, would the extra expense of the RT disabler still be a good idea even if it doesn't address my original concerns? It's $189 and I would consider the investment in it if performance overall is improved since I, hopefully, will keep this truck for a long time.

Thanks for all the help.

 

[CKN]

Originally Posted By: Sierra048
I've read the replies three times. I'm getting the impression that what I descibed isn't due to the AFM system. Is it more associated with the transmission programming?

Azjeff, how do you monitor the change between four and six cyliners. I don't think my display has that function. Your truck is two years newer so maybe they upgraded the display. Or did you have to buy an upgraded display?


SteveSRT8, I appreciate your suggestion on the tune. Maybe a little over-cautious but I just don't trust dealerships and don't want any excuse to deny warranty coverage if a custom tune left a footprint, even though not responsible. Out of warranty, I would certainly consider it.

OLEJOE & CKN, I learned how to drive on a manual transmission, but this is the first vehicle I've owned that has both capabilities. Short of using M1 to get up two short hills to reach our home, I've not used the manual capabilities. Can you please describe how you use M5. Do you have to go through all manual gears to get to M5 or can you just select M5 after being in auto mode?

To everyone, would the extra expense of the RT disabler still be a good idea even if it doesn't address my original concerns? It's $189 and I would consider the investment in it if performance overall is improved since I, hopefully, will keep this truck for a long time.

Thanks for all the help.


You set the gearshift to manual-and then move the little manual selector button to the "5" position. The truck will then shift through all gears except 6th. It will not go in to AFM mode this way. As I mentioned-I use in town this way all the time. Also, when I tow my 5,500 pound trailer-I use manual gearing a little more.

 

[AZjeff]

S048, my truck is so stock the only option was carpet. I can scroll through 5 or 6 displays on the little screen between the tach and speedo, the V6/V4 indicator is on the average MPG display, maybe you don't have it. Do you have the hill holder deal where it downshifts going downhill to hold speed? To disable it you press the tow/haul button for 5 seconds. Might do something for you.

 

[TiredTrucker]

One of many reasons I dumped the 1500 series pickups and moved on to the 2500. No AFM to deal with in the 6.0L. Many claim to not notice AFM changes, but I sure could on my rural two lane roads. Would cause excessive shifting and gear hunting on the rolling hills of my area that was reduced when I used the Range device on my 2013 1500.

 

[Sierra048]

Thought I'd give an update to this thread I started. I broke down and got the RT dsabler. Going up the hills I referenced earlier, there does seem to be less hesitation and the "down-shifting sensation I felt before. On my instrument display, I don't have an indicator showing what cylinder mode I'm in like some others do. So far, I'm not disappointed with my purchase. I'll let you know if that changes.