Hi All,

As a C2 guy, my new 2017 Grand Sport is a delight. Learning all the major and minor differences 50 years can have on a car. Noticed that there was a shudder that would wave through the car. Mostly felt it through the seat. Checked in with the forum and the two threads were the AFM or torque converter (circa 2015-2016). I noticed that the shudder only occurred when in automatic mode and was not speed dependent. When I would put the car in manual and paddle-shift, the shudder disappeared. A little bit of research and I found Range Technology AFM disabler (Range). It arrived and it was a 5 second plugin to the ORB ll and the shudder was gone. Even though the high speed shudder was mainly what I was trying to get rid of, it was surprisingly smoother and quieter at the low end as well. Very happy camper.

Why AFM at All?

Speculating, GM probably needs to put AFM on all their V8's and V6's to up their overall EPA mileage rating. Makes sense to put it on for that, but a bit crazy for a Vette. As an engineer, I would have disabled the AFM when Sport or Track mode was selected. Again, my guess, is that doing that may have been an EPA problem....

Questionable GM Dealer

I was due for an oil change and took the car into the dealer where I bought it. Mentioned the shudder in passing and the service advisor called me back to his office to tell me that it needed a new torque converter. This guy was 100% FUD (fear uncertainty and doubt). In a retirement community, I suspect they prey on older people...especially when under warranty. I told him I was familiar with the torque converter problem on the 2015-2016, but was told by Corvette engineers that it was a faulty supplier and the corrected the problem in late 2016. Needless-to-say, I hoofed out of there. His parting words were, "God forbid you have a problem." I told him that is what tow trucks are for and that God was too busy to worry about my Vette.

Warranty?

Range tech support and my "new" GM dealer said there is no warranty issues because it is a plugin and does not modify the firmware. It merely cuts off the AFM leaving the car in V8 mode all the time like Duntov intended.

Just Reporting

Hope this helps other experiencing the same weird shudder. If you are experiencing a shudder, put it in manual in 8th gear. The shudder should disappear. If not, there is something else going on.

Hope this helps!

Bob

 

I ordered my Range last week and am just waiting on the post office to deliver it. At the rate it's going, I think Pony Express would've been faster.

 

I ordered mine from Amazon because of two-day Prime. May not be the post office as I have found that a number of vendors create a shipping label automatically, but don't ship for a few days. Not sure if Range is that way, but you are fairly close to them....

Looking forward to hearing what you think. My difference was remarkable.

Bob

 

My 2016 Z06 has either been in manual more or had a Range module plugged in every time I drive it. I will be sending mine in for the latest update to remove the battery drain that occurs with older models.

AFM is bad enough but the abuse of the torque converter lockup clutch in an attempt to reduce vibration should go in the engineering stupid hall of fame.

 

Really good point! I have had to punch it a couple of times to avoid someone. When I did, it really smacked the transmission. It really felt hard and had a delay compared to the Range. It seemed to have to change over to V8 and then tried to catchup when a rang down to the engine room.

Bob

 

I don't have any Shudder but I have had the Range Technology AFM disabler for about 1 1/2 years. It's not without its faults! Unless you have a cable with a switch on it you will have a dead battery after a couple of days if you leave it on your car. After my car was locked in 4th gear with numerous faults in my DIC I stopped using it. I did get it updated about a year ago but just stopped using it after reading about numerous others having the same problems even after getting the updates. Hope it works out better for you.

 

According to Range the V8.6 software has a true sleep mode so the battery drain issues have been alleviated. I have had a V8.6 unit in my 17 GS for over a month an a half (its driven every other day so lots of starts ) and no CELs. I haven't had time to put an ammeter on the car to see if it does really not have any current draw with the car off. V8.4 did the above after 3 starts on my car.

 

Have you tested the sleep mode yet to verify it actually works? I used my range for a couple of months before I had my first CEL and problem. Hopefully they are having better luck with the updates.

 

There are several people now using V8.6 on 17s with no reported problems. As I said I haven’t tried to check current draw with and without the range installed yet.

 

Just to clarify...I have read that if you do not purchase directly from Range they will not warrant or update the product at no cost. Yes? No?

 

This is correct. According to what has been reported here on the forums, to get the free updates, you have to purchase directly from Range. This is why I bought from them directly and not on Amazon. Mine's supposed to be delivered tomorrow.

 

I believe that if you purchase from one of their authorized vendors, the update is free. They list what is authorized and not on their web site:

• Range Technology Website
• Range Technology on Amazon
• Other (unauthorized) Amazon seller
• Ebay (unauthorized) seller
• AutoAnything (AUTHORIZED DEALER)
• Other AUTHORIZED DEALER (see our website for more details)
• Gift (unknown)
• Other/UNKNOWN

One thing is for sure, if you get it from Range, they will send you the latest version. Other vendors, it is whatever is on their shelf.

 

Be careful with getting a Range from Amazon. I did exactly the same thing you did and received an older firmware version (8.4 R1). I called Range and was told that they have no authorized dealers on Amazon or eBay. I returned the one to Amazon and ordered the current version (8.6 R1) directly from Range for the same price.

 

Good luck if you ever need an upgrade because Range won't do it unless it was purchased through them. They will do free updates when required but not on units purchased elsewhere.

 

Send it in for the upgrade. It is now a fault free device.

 

Yes

 

lol God is indeed too busy to worry about Vettes. haha!!

-Josh

 

Although I agree that AFM is a stupid idea on a performance car, I do have sympathy for the engineers who have to engineer cars to meet CAFE standards. AFM (and start/stop) technology are desperate attempts by car manufactures to meet unrealistic CAFE requirements. Clearly, if given a choice, the engineers would not install AFM on the LT1/LT4. My beef with GM is that they did not program the A8 like the M7 - AFM active in Eco mode only. Thankfully, Range has finally worked out the kinks in their disabler. So, now us A8 owners get to spend $200. to disable technology that never should have been there in the first place.

 

Well, I might have spoken too soon!

My Range Disabler worked for a few days and then I had a weird experience that now is duplicating regularly.

One day a fired the car with the Range Disabler in the slot. The engine sounded funny and when I put it into drive, it went into 4th and stayed there. Tried to manually shift and it would not. Check Engine light came on. Pulled the Range Disabler out and restarted. Went into gear normally and after a few miles the check engine light went out. ...but of course, the shudder came back.

What I know is that if I put the Range Disabler in after running the car without, it works perfectly. Next time I start, it goes into the 4th gear error. Must have tried ten times and it always follows the work, then no work error.

I contacted Range tech support describing the problem, but have not heard back.

Has anyone had any similar experience?

Has anyone tried the DiabloSport Disabler?

Moreover, has anyone found that a Vette dealer can fix the shudder with a firmware update?

Thanks for help and thoughts.

BTW, I used my OBD2 unit and software to clear all the error codes. Did not help.

 

What year is your car and what version do you have....