I have around 5000 miles on my 2017 C7, A8 GS, of which the last 2000 have been with the Range Module always plugged into the vehicle. Is it a wise idea to run for, say around 100 miles, without it plugged in? My thinking is that whatever electronics and mechanical parts control the V4 mode should occasionally get exercised. The 100 miles is just an arbitrary number I made up. Maybe it should be longer. We do not have vehicle inspections in our state, so it stays plugged in all the time.

 

An interesting question.

The electronics certainly do not care. I cannot think of anything mechanical which needs to be exercised. Thus, I would not bother.

We know one needs to pull the unit and drive a bit before emissions testing, but this is a different issue.

Others may have more insightful responses.

 

The purpose of the range device is to keep AFM inactive to reduce the chance of failure ,especially with the lifters which are known to fail and when they fail they fail big ... also to prevent the issues with the A8 lockup torque converter when the car goes into AFM mode

A range has been plugged in my 2015 A8 since the day I bought it and now at 47,000 miles , I have AFM disabled in the tune

So my opinion, there is no need to " EXERCISE" AFM unless you need to unplug the range to pass emissions

Dave

 

I agree with both above posts.

 

I live in a state that does test for inspections. Last year I went in for an inspection and they unplugged the unit to plug in their electronics and the vehicle would not pass inspection. The shop told me to drive it around for 100 miles and bring it back. I did as they asked and everything returned to normal and the vehicle passed the inspection. I only say this to those who may have warranty claims where the dealer may need to plug into the OBD II. Many dealers will void your warranty as they will say the car has a tune. Other than that, I run this on all of my vehicles.

 

This is how internet-based rumors get started
Nobody will say the car has a tune as the range does nothing to the orginal tune or CVN files which is what GM looks at to determine is the ECM tune files were modified . All the range does is fool the AFM module into thinking that the requirement for AFM are not met using the CANBUS .( communications bus) .. . Heck my dealer even knew what the range was because he has seen so many if them as the range is not just for the Corvette....
Dave

 

Hard to know exactly. Seems like there was a thread not too long ago where a guy lost his extended service contract for having a Range device plugged in when he got there or recently unplugged (story was unclear to me). He supposedly ended up paying for a new torque tube and some other stuff.

 

Had mine emission tested this morning. Only had the device unplugged for about 15 miles and I passed............

 

Anybody that let a dealer deny a torque tube repair because they had a range plugged in ...... needs to hire a lawyer as this is a case where the Magnuson Warranty Act would hold water , I would love to see how a dealer would prove that a torque tube failure was caused by a range device .... with how many range devices that are installed you don't think it would be all over the internet that it voided others warranties???? . I am confident that there is more to the story

Dave

 

As reported.. It seems you can void your EXTENDED warranty if you use a Range device. Up to each user to take the chance leaving the device in when going to the dealership.

Still not sold that AMF causes the transmission issues as reported. If anyone has any official engineering information that supports this info, I would like to read it. Don't toss rocks.. Just want too see proof that the AMF system causes the trans issue. I'll buy a Range device if documented proof can be sent my way..

 

I prefer to keep it in V8 mode. My thinking was that the next owner may want to use the V4 mode. I do have another 5 years of extended warranty, so if something goes wrong with the V4 stuff, it is a no cost fix, I would hope. I do see a C8 in a few years. Most electro-mechanical systems do better in the long term by operating them regularly. Connectors, cables, electronic component corrosion, springs, valves and whatever they put in to achieve the V4 mode could have a problem over time. Seems to me that running in V4 once in a while would verify that all is OK. Sort of like running the home standby generator to be sure it starts and generates power.
Maybe I will look at it as if I need to go do one of those inspections every year. Probably no correct answer on this one.

 

Probably living on the edge if you go to a dealership with the Range device installed while under an extended warranty. Do a search for post about having a extended warranty canceled due to a range device. OR call your extended warranty company and ask them.

IMO.. A Range device is perfect if you don't want to run in 4 cylinder mode. But probably a waste of money if you think it will stop the transmission shutter issue.

 

As reported by who .....some guy on internet lol lol show me the data ...

AFM did not work in the 80's and it still does not work in 2020 yet it keeps getting jammed down our throat to satisfy some CORP fuel economy standard that GM has to meet
Anybody remeber the 4 6 8 engine that was installed in the 80's Eldorado lol

There are two problems here with 4 cylinder mode

With AFM no proof needed just ask anybody that has suffered an AFM lifter failure along with sometimes wiping out the lifter bore or cam . AfM lifters and the system that operates them is full of issues

The second problem is not really an AFM issue but a result of the car going into 4 cylinder, the shudder issue with the A8 , GM is blaming it on hydroscopic fluid ... which might play a part in it but it really is caused by the TCM programing and how the TCM locks up the converter during cruise situations, the TCM does not actually lock up the converter as that would pass the unbalance vibrations of running in 4 cylinder mode to be passed thru to the driveline , The TCM pulses lockup never achieving a full lockup. The real cure is to modify the TCM programing which they did and is part of the triple flush procedure along with a garage relearn procedure ( Google it )

Want proof ... ask anybody who replaced the stock converter with an after market and tuned the transmission .... I still have my stock converter, and that nasty old hydroscopic fluid but..... I have the latest TCM firmware and my trans has been tuned .... 47,000 miles of no shudder for me

Hence the reason why folks use the Range , stop AFM , stop the TCM from pulsing the converter
There are some cases where the converter is to damaged and the fluid or the programing is not going to help
Then there are other issues that setup a harmonic imbalance that mimics the trans shudder Everyone is quick to blame the trans and do the flush when a simple pico test would point to the real cause of the shudder ....which is usually the heavy runflat tire balance

Don't by a range no skin off my back but if you experence a collapsed AFM lifter because you want engineering data lol lol

Heck just Google AFM lifter failure

Dave

 

It won’t hurt anything to remove the Range device temporarily and then reinstall it.

I too have heard stories about members failing smog inspection due to the car stating not ready for testing if the Range device was just removed. Might be good to drive the car a bit after removal just to be sure.

 

Here's where I am with my Range device.....

I no longer use it in my Stingray. I simply drive in manual mode all the time.

I normally drive with the device plugged in all the time. I was initially sharing one device between my Avalanche and Stingray. One day while driving the Avalanche without the Range, I noticed a Check Engine light. I immediately pulled the code and found P0420, Catalyst System Efficiency Below Threshold on Bank 1. I had just installed 4 brand new O2 sensors and 2 brand new catalytic converters. We (the dealer and I) went through the series of checks...making sure I had good sensors all the way around and I eventually forgot about it because they couldn't find anything wrong with the sensors or the truck. I needed to put some miles on my Stingray for the extended warranty period, so I parked the truck for about 2 weeks.

While heading to Lowe's one day, I hopped in the truck and then thought to grab the Range device. Popped it in and went about my day. Forgot all about the CEL because it was gone by the time I looked at the display.

To go along with my newly assigned science project, I disconnected the device that afternoon and drove about 15 miles away. The CEL returned....same code. Connected the Range and the code disappeared instantly. This went on for the next 600 miles.

I know there's a genius out there who can tell me what the exact cause of this was, but until I run into them, I am not using the Range in my Stingray again. Manual mode works fine for me...

 

^^^
Have you contacted the manufacturer?

 

I did...all they did was confirm that I had the most current firmware. No other support was offered...and I am selling the Avalanche to CarMax tomorrow.

I've actually driven in Manual mode so much that I don't believe I would drive the Stingray any other way.

#MrFlappyPaddles!

 

They certainly were not of much help.

 

I am the genius , lol lol the range software clears emmison related codes upon startup to minimize issues when it commands NO AFM , it also clears all the emmisons ready data , that's why you won't pass an OBD emmisons smog check as they will all show "Not Ready"

Now if you drive it long enough for the ECM to do a second check. U will pop a code as its only on startup that it clears any code
Dave

 

Apparently it wasn't the dealer, it was the service contract people. Like you said, we only know what was revealed by the story teller.