I am curious to know how many have never had any issues with AFM on their C7? There have been numerous posts from folks that have experience problems, but like most things, you generally only hear from those with problems. I have never had an issue on my car.

 

No issues with AFM or anything for that matter regarding my '17 GS.

 

I had no problems with AFM on the 16 Stingray with the A8 transmission that I had, but when I first bought it I read a bunch of posts about it on the forum and bought a Range Device to keep it from ever going into 4 cylinder mode. Simply plug it in and it keeps it in V8 mode all the time. No problem but didn't want my car's engine deactivating cylinders. Figured it might cause a problem over time.

 

No problens with my '14

 

If the AFM causing engine failure was a foregone conclusion, you'd be hearing about it outside of forums. Is it possible, sure. I'd say it's more of a weak point than a failure point.

 

There are so many variables with the AFM how often does it go into v4 then v8 mode how many miles on the car. Someone can tell you they have no issues with their vette but it only has 4000 miles. I think the constant v4 to v8 are one of the reasons the A8 has issues along with the older fluid. Not to mention there are so many parameters that cause the AFM to go out of v4 its crazy. Seems like its in and out way to often causing issues. Could I be wrong? Sure I am no mechanic but I have commen sense. My commen sense tells me the AFM juice isn't worth the squeeze. I didn't buy me vette for gas mileage but it gets awesome gas mileage without AFM. So if the AFM provided some great benefit and no one had actually proved it caused issues then I would say use it. As it stands it really provides little incentive for me to use it, unless your on a long trip and I still think the benefit of that is of littlle benefit. So since not every motor or trans has an issue it is obvious there are issues as we can see with atleast the trans and some with the motors. Honestly it's a roll of the dice maybe you get lucky or maybe you never drive your car. Either way I bought my 19 GS new, already had the new trans fluid it was built 04/19 and I immediatley put in the range device. Does that mean I will have no issues nope but it makes me feel better I am removing what I can that may contribute to the issue. Atleast I am not causing any issues by what I have done.

 

I agree 100%, installed the Range Device for peace of mind. I am not a technician like you have to be now days, but in younger years was an SAE certified mechanic even though I didn't make a living at it. That being said, I see no benefit whatsoever in having my engine and transmission going through the process of shifting in and out from 8 cylinder mode to 4 cylinder mode. The mechanic or technician that works on my primary vehicles warned me about AFM on GM products a few years back when I was looking to buy new vehicles. It is not just a C7 thing, he said there were problems with all vehicles that were equipped with AFM over time, easily deactivated. Of course, that was just his opinion, but he works on them everyday. I am sure there are exceptions to every rule but why even take a chance on it.

 

chevy will change the automatic fluid to the newer fluid no questions asked under the powertrain warranty

 

Sorry new to C7. Obviously there is no permanent off switch for the AFM? You must get the Range Device?

 

Yes it's the only way unless you get the car tuned but that will void your warranty. It's 189 on the range site https://www.rangetechnology.com/prod...-dfm_disabler/

 

Yes, Range Device is very easy to install, just plug it into the port under the dash under the left hand side close to the hood release. Plug it in, crank the engine and let it run for a minute or so, it will go through a cycle where the lights flash a few times, when the sequence is done, will deactivate the AFM. You can buy a new one from Range Technologies but there are always used ones on the forum for sell. I consider it to be a very good investment. Seems like they are around $200 for a new one from Range, used ones are usually around $110 or a little more in the for sale section of the forum. Personally, I would just get a new one to get the latest device and set up. Just make sure if you take it in to a dealership to have it serviced or checked out that you unplug it before you go in and just plug it back in when they are done.

 

Thanks for the responses, on my list.

 

I have over 30,000 miles on my 2018, and I don't have the Range device, and I drive in manual mode only maybe 20% of the time, so the majority of my driving is with the AFM system active. Not a hint of a problem here so far.

 

As I indicated previously, I have had no problems with the AFM. My C7 is a 14 with the A6. Is the A8 in later years more prone to AFM problems then with the A6?

 

35,000 A6 and it goes into V4 as often as it wants to. No problems.

 

with the M7 it only works in eco mode.

 

No trouble on my 17 GS with 15k miles, but I did install the range at about 5k and had the A8 flushed with the latest fluid at 10k.

 

Another alternative is to drive in Manual Mode and shift with the paddles.

 

I once read an in depth explanation as to the issues of the AFM system (I believe on the chevy truck forum) and the main opinion of the contributers is that when going from 8 to 4, there are suddenly four pushrods/rod bearings that aren't under any "load" like the other four that are still active and doing the work. This lead to the belief that there were harmonic imbalances occuring which over time could lead to serious issues. There was IIRC also mention of the lifters themselves and excess wear. I've spent a lot more than $200 on really stupid crap in my life so if the range device can help prevent anything questionable, I consider it money well spent.

 

I put the RANGE on my 16 but to late, the torque tube had to be replaced due to one of the bearing going bad, Then GM wouldn't pay for it even since I had extended warranty. They said I lost my warranty when I put the RANGE in the car. Cost me over $5200 to get it fixed.