50th year

Seems to be a lot of opinions on using this device. Some love it , some say it hurts your motor others say it voids your warranty. I sure would like to get rid of the 4V mode but unsure if its worth the risk. Anyone know the real scoop?

NSC5

The only downside I found to the Range was it would rarely set a code at startup in my 2016 Z06. NO damage was done, it simply caused a communications error with the TCM and a restart restored it to normal operation. It never caused an issue when I switched it on (via a switched OBD II extension cable) after starting. You need a switched OBD II cable to use with the Range or otherwise you will have to unplug it when you are not driving for a few days to avoid a rundown battery and the OBD II connector wasn't designed for this sort of continuous plug/unplug environment.

Now I drive mostly in manual mode and rarely use the Range anti-AFM device but when I use it the device works fine. It avoids the workout the torque converter clutch gets in AFM mode and avoids potential uneven cylinder wear issues in high mileage vehicles.

My first choice would be an option to pay extra not to have all of the AFM hardware garbage added to the car in the first place. Next best would be to have A8 cars operate like M7 cars with AFM only in eco mode. Since neither of these is an option the Range module is the next best choice. It doesn't "tune" or change the programming so you won't have warranty issues from it.

If you have a Z06 like me AFM will not engage frequently like it does in the LT1 equipped models but I expect that over a longer period of time automatics in the Z06 would start to show some of the same AFM induced shudder issues as LT1 equipped models.

davepl

I was told that the module bled power when plugged in even when the car is off, such that it'll kill your battery over a couple of days if not driven. That's a non-starter for me (rimshot!). That's what I read here, anyway.

Plus I don't care about V4 mode and it never annoys me... and even if it did, dead batteries suck more.

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Dave,
The power drain is why I used the switched OBD II extension cord for the Range. I am much happier switching off the Range instead of dealing with transmission issues from the almost properly implemented AFM system. With our LT4 equipped Z06 we aren't at as much risk as the LT1 equipped Stingray and GS which go into AFM very frequently but long term that constant cycling of the converter clutch during V4 operation will probably catch up with the LT4 equipped cars later in life. The diagnostics GM uses (does the shudder disappear when V4 mode is off) when checking for shudder is pretty telling as is the glut of problems with the V4 prone LT1 equipped car but the near absence of the problem in LT4 land.

I don't expect the current "magic mouse milk" transmission fluid is going to continue to mask the problem long term.

If you plan to trade the car while still in warranty and are willing to deal with converter clutch replacement(s) [several forum members are up to 3] then AFM is fine but I don't want to deal with it. Choosing between shudder and dealer tear down of the transmission versus remembering to switch off the Range module is an easy choice for me but I understand that others feel differently.

davepl

I bought the 10 year warranty so I'm OK if the clutch packs it in at some point, though I still hope it doesn't.

I don't get a shudder, tho. I get a change in exhaust note to a low rumbly sound, more noticeable since the Corsa midpipe, but that's it. I'm starting to get used to where and when it does it, certain coast-down hills near my house, etc.

I'm not sure what you mean by "switched OBD II extension cord". Do you mean you have an ALDL extension cable with a power switch on it so you can turn the module off without unplugging it?

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That is correct Dave, it just has an inline switch.

The sound going into V4 will be more noticeable on your car even if you hadn't installed the different exhaust system. Our Z06 model doesn't have the extra set of valves in the exhaust pipe used to reduce the sound difference in V4 mode; these are found in the base Stingray but I believe they have since been deleted if you order the Z51 package since these valves don't do well with heat.

I briefly tested my Z06 when it had about 2,000 miles on it and the only time I found it would go into V4 mode was going down hill or decelerating on the interstate, in lower speed driving cruising at somewhere under 50 seemed to also activate V4 mode. But a regular C7 will go into V4 mode far more frequently since it activates under a wide range of conditions.

Flame Red

Ok, I'll ask. I see Diablo has one of these. Hard to tell if it is just a re-branded Range, or truly something they developed. I could not find any reviews. Does it have the same parasitic battery drain, and the SEL the Range can have intermittently?

http://www.diablosport.com/shop/spri...nt-module.html

Cosmo Kramer

I hade a Range AFM disable device installed on my '09 for two years without any issues. So, I bought one for my '17 A8 GS. The second time I started the GS the car went into "limp" mode (started in fourth gear, check engine light, and "reduce power" message.) I tried restarting the car, but got the same message. From there, I unplugged the Range device and the car started fine. This kind of "spooked" me so I returned it. By the way, the device was version 8.2.

I really hate AFM and think its purpose is to reduce emissions. From my experience, there is no difference in gas mileage between AFM off or on. Yes, I know I can disable AFM by putting the A8 in manual mode, but I bought an automatic because I don't want to manually shift gears.

If Range can figure out the "limp" mode problem and not draw down the battery when the car is off, I'll buy another one. Till then, I'll just have to live with AFM.

CP

Do you have a link to the OBD II extension cord with power switch?

Flame Red

Just be aware that if you also use an OBD Y cable for a Window Valet, the switch must go after the Y cable or the Window Valet will not work even with the switch on for some reason.

VLADIE22

I would call it a band aid rather than a permanent fix for the AFM. Mine does what it is supposed to do MOST of the time . Every now and then though , it decides not to work and the car goes into V4 mode ,other times it throws a CEL . Im seriously considering getting a Diablosport tuner to disable the AFM for good.

Oskee

Called Range Technology to order the AFM disabler. They said the newest version for my 17 C7 Z06 is the 8.2

Bad news is that they cannot ship or sell to California because it is illegal for use in our state. They did apply for a state EOD number which would allow them to ship and sell to our state but so far nothing.

So for the time being I will just keep it in manual mode to keep it out of V4.

vbdenny

I put the Range on mine right away. I also bought the extension OBDII cable with switch. Simple. It drapes nearly invisibility across the steering column leaving the switch on top. Click it off when you park and no drain. Works seemlessly

lgodom

Looks almost identical to the Range AFM device.

jcthorne

Truly unfortunate that Range cannot build this device to work properly and turn itself on a few seconds after the car starts and off when the car shuts down. Most all other OBD plug devices have this figured out and work fine. I really would like one of these on the car, but not with its known defects.

Yet another great product idea ruined by a rush to market with a half baked implementation.

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I agree with your points and Range could easily implement this for existing units by selling their own Range branded OBD II extension cord with a tiny solid state relay that functions as the power switch opening as soon as ignition power is lost and a very simple R/C delay would allow it to come up a few seconds after the car is started.

JonMN

I also sent them a note suggesting a time delay to start. I am on my 4th iteration (8.2) and still have the occasional CEL. Since the unit is supposed to send an "all clear" when plugged in with the car running, I think a delay to allow the rest of the car diagnostics to complete would fix both the drain concern as well as the CEL. I am driving most of the time in Manual now, so only plug the Range in occasionally.

Flame Red

Well I got curious about the Diablo product and asked them about it. Here is their reply...

I take that means is it just like the Range product.

I started looking at ODB2 stuff and I am not seeing any existing product that does this - at least so far. I found a few threads about this with this one being the most relevant.

Looks like ACC mode is not available in the OBD2 pin outs so the accessory power would have to come from somewhere else.

Come to think of it, I seem to remember buying a few delay relays and have them in the garage somewhere. Those relays wait some period of time and then provide power. So it would give the engine and CAN bus some time to stabilize once the car starts before it turns on the AFM disabler.

I might have to buy another OBD2 cable with a switch and see if I can rig this up.

SMT1004

I just installed the latest version 8.2. Got tired of the seemingly constant changing from V8 to V4 mode and change in exhaust note. To me going from V4 to V8 also seems slower response when stepping on the gas. With the AFM Range Disabler it has increased my enjoyment of driving. No issues in the short time I've had this installed. I did use the cable with on/off switch to avoid a dead battery as my car does sit for a week at a time.
Tucked everything up under the dash:


My blue LEDs are lighting up the area. Little piece of tape reminds me what position 'on' is

MichaelO

Option 3: I think i would take the basis of idea 3 and modify it slightly. I would use a relay instead of a switch to make it automaticly turn on once the car is turned on.
Get an OBDII extension cable and hook up the power wire to the N/O (Normaly open) relay contact.
Take a switched 12v acc power and an earth/ground wire to the coil of the relay.

Every time the car is turned on the switched 12v would power the relay coil, causing the N/O contact to "Close" allowing power to pass to the OBDII device. When the ignition is turned off the power is lost from the relay coil dropping out the contact.


Yup, good idea, I thought of this too. A startup delay on turn-on would be nice to allow CAN Bus stabilization.