Thanks for the update Thunder. Looks like the on/off switch is the only solution as of now. Shouldn't have to be, but seems as it is.

 

True, but what concerned me more than the CEL is the transmission getting forced/stuck in 4th, not sure if that would or wouldn't have happened if I had used the on/off switch (i have one).

 

stay away from Range AFM; CEL central!

 

Part of my job is to manage software vendors. Without fail,they all claim the next release will fix all your problems ('which is really their problem: buggy code). I have one vendor that has made the claim over 3 or 4 different releases. Over the course of a year or so we tried to work with them but the inevitable does happen: drop them and go with another app.

 

Fourth gear is protective limp mode for the 8L90 transmission and it does this when the TCM cannot communicate with the ECM. The LT1 and LT4 both have plenty of torque to take off from a stop in 4th gear and the normal operating range of 4th gear is from around 22 MPH up to around 120 MPH depending upon the rear axle ratio of your model.

This has been the fault problem with the Range since the beginning. If you turn on the Range after the start it won't have this problem because the TCM and ECM have gone through their initial communications protocol. If you get this error at startup simply shut off and remove or turn off the Range module and restart and this will allow the transmission to resume normal operation. If you plug in or turn on the Range after startup it will clear the DTC that was set during the previous start attempt.

It is a nuisance but still better than the potential torque converter issues from V4 mode, sort of like the difference between a splinter and a broken leg and most of us would opt for a splinter once in awhile if it helped us avoid the broken leg.

 

yes, thanks for that, i'm aware of it, but great info for someone who isn't

I'll wait for Range/Diablo to get the firmware fixed and just drive in manual for now. I'm not interested in dealing with workarounds (I've got a 25 year career in technology, it's the principle )

 

To all the testers of the Diablo - thank you. Sorry to hear that it is indeed just a rebranded Range module, and not running their own firmware. Most disappointing.

To all the other forum member that are suffering the problems, here again is the procedure to build a Relay with a OBD cable to turn it on and off delayed after start. It is cheap to build and easy if you can solder three wires. It does require a switched 12v source. A better solution would be a relay that can sense the starter voltage drop, but that is beyond my meager abilities: How To: Range AFM Disabler – No More Parasitic Battery Drain via Relay in Cord

My only update is that since I wrote the above, I have removed the second optional "manual" switch cable. I just left in the relay switched cable. I never manually turned off the switch. So I removed it so that I don't accidentally manually turn off the Range. Less is best

 

not true; Range is junk; codes do NOT reset automatically. Why try to defeat GM engineering and warrenty. An engineering fault by GM may be delayed but will ultimately be revealed in time; the range is junk and won't accomplish what u think it will.

 

wait.... what?

 

Yeah, it was long revealed here. AFM is junk and was a bad idea from GM. They should have left it off the LT1 like they did on the LS3 on the C6. For most of us, especially the A8 owners, our cars will be in the scrape yards before GM admits their mistakes.

Usually the aftermarket solves the OEM issues eventually.

 

We don't know if AFM is the root cause of the problem; it may just accelerate the symptoms. Defeating AFM will only delay the symptoms. If that is your goal however, Range IS NOT the solution. It is JUNK and a whole separate issue. A cure that throws codes and has to trick a system to be effective is NOT a solution.

 

The RPM variation and shudder are from clutch wear, that is why it shows up with increasing frequency as the miles add up. The converter clutch suffers very little wear in normal (non-V4 mode) operation and does its part to provide better mileage. A replacement torque converter does cure the problem for some time as will the triple flush with friction modified fluid.

I have had zero problems with the Range module when it is switched on AFTER starting the vehicle and it works exactly as it should if you follow this step. Earlier this week I did forget to turn it off before starting after filling up and it set a CEL. Restarting the car allowed normal transmission operation and when I turned the Range back on it did the reset as advertised and turned off the CEL.

I would much prefer GM had never added AFM to the LT4 but they did and they aren't going to remove it. Rather than deal with torque converter issues or bitch about the best currently available solution to the GM designed in problem I am enjoying driving my Z06 with the Range module. If a better solution comes up I will adopt it but in the meantime it is great to have a high power car with a fast shifting auto and no shudder/RPM variation.

 

My Range failed yesterday. CEL and stuck in 4th. Same as many others. I do not recommend this product. Bought in June..maybe put 400 miles on it.

 

I have followed this procedure of turning it on after start up and so far zero issues. I do wish GM had provided an option to shut it off. The car drives much better and is much more enjoyable running in V8 mode 100% of the time. As this is the only current option and does not effect my warranty I'll continue to run the Range module. I certainly will report back if I get a CEL using this start up procedure.

 

Lets hope version 8.3 solves the problem.

 

Get you an OBD switched extension cable, and follow this procedure. You'll be fine.

 

I don't get it. Why doesn't Range or some "enterprising" individual manufacture a cable with a delayed start? Yes, I did see where somebody spliced a relay into a on/off cable. If I could buy a manufactured "plug-n-play" relay cable, I'd buy one in a heart beat. The problems with the Range device (CEL and parasitic battery drain) could both be solved with a relay device. "Two birds with one stone."

 

I just received an email reply from Range based on my inquiry about the latest version available. They said it was 8.2 for my 2016 C7. I plan to send mine in for an update on Monday. Are they working on 8.3 to solve issues on the '17 cars?

 

They told me 4 to 6 weeks for 8.3. You know how that goes

 

8.2R is what I tried on my '17