JRS 94

Trans Codes came up along with PO300 today while making WOT passes. Car went into limp mode. Ran normally after stop and restart. Code was cleared by disconnecting battery. Hasn't returned yet. Any ideas why this came up?
Car is an 08 with an ECS SC kit, headers and a 3000 stall. Roughly 550 rwhp.

Proracing

Sounds like your trans is slipping, it's the same thing that happened to me, I had the same codes. These trans are pretty good up to about 500rwhp but once you go over that they start to slip usually in 3rd. I was also running 550rwhp when it happened to me. You'll probably need to get it rebuilt, you can have it tuned to raise the pressure but that is only a bandaid. You can always opt for a new stock one but it will eventually happen again. I have a fully built 6l80 that will handle 1000+ for sale if your interested. It has a full warranty and they will tune it for your car at no charge. Let me know if your interested. Either way i hope this helped a little and wish you the best however you decide to fix it.

JRS 94

Thanks, for now the codes cleared and the car is acting correctly. Time will tell.

ironhorse583

this is what a trans tuner told me

The code P0716 is setting because the TCM thinks the turbin (input) speed is out of range. I'm gonna guess that it sets after a moderate to hard acceleration run and goes into "limp" mode. Once you turn off the ign and restart the shifting is back to normal. Some 6L80's seem to be more sensitive to this than others when a higher stall speed torque converter is installed. We have had about a 50% success aleviating this code with a speed sensor replacement, (the speed sensor assy can be serviced with the tranny in the car. The valve body has to be removed to replace the sensors). If the speed sensor replacement does not cure the P0716, you will need to get a tuner who has EFI Live to disable that code. Unfortunatly, HP Tuners does not have that capablility yet.

JRS 94

Thanks this fits my situation exactly, if it comes back I'll most likely have the code disabled.

bp92gsr

Is this Mike from Century? Sounds exactly like what I discussed with Mike today bc I am having the exact same code pop up. Is EFI live the only tuning software that can disable this code? Also, if this code is disabled will the trans ever be able to go into limp mode ever again? My guess is no and this will be the only protection to keeping the tranny alive longer by the TCM commanding the trans to go in limp mode.

DOUG @ ECS

Common problem with a converter car, if the trans was legitimately put into limp mode from this problem, it is already toast, so I would not be concerned about shutting it off. It's more of a "get the car off the highway" mode then anything else.

bp92gsr

Doug, if this code is indicative of a trans being toast then how does the trans act like normal when the code is cleared? I've had this go wrong in my 6l80 two years ago when the car was last owned and all he did was replace the input speed sensor along with fresh atf and the trans just now through the same code 716 two years later with zero issues making running 10s with 1.5 60ft.

DOUG @ ECS

Sensor failing is a different story, when the code comes up from a slipping condition the limp mode jacks up the line pressures to max to limp it home. At that point the trans is already shot.
If you do not have a converter and are receiving that code again you are a rarity. Things happen, hope that helps.

kapkanimd

Did you ever figure this out?

I have a built 2011 GS A6 as well (procharger, cam, meth, headers, etc.) w/ nearly 700whp. I am having the same exact issue EXCEPT completely unrelated to hard pulls. It has happened 3 times (all about a week apart from each other) so far all the same scenario: I am coming up to or sitting at a stop light, I will feel a slight jolt and the check engine light will come on (I am assuming just the random misfire code), then when I start driving it will go up to like 2k rpm and then not go any further. Ever time I get the same codes: P0700 (Trans Control System - MIL Request) & P0716 (input/turbine speed sensor circuit range) come up as Pending Fault codes and P0300 (random misfire) comes up as a historic fault.

One thing I tried was to shift manually in case it was something with the downshifting in automode, but I got the code again today when using manual shifting (though less or no jolt this time). I did notice though that as soon as it happened it popped out of manual mode (the gear indication disappeared from the HUD).

I have a bluetooth OBDII scanner, so I just clear the code and continue on my way with no issues until it happens again, but it is really discerning and I want the issue fixed. I use this as basically a daily driver for the past few weeks just so I can make sure there are no ongoing issues like this one. I have put about 200 miles on it in past 2-3 weeks..

I bought a new speed sensor and I will install it this weekend to see if that makes it go away for good. Other posts I have read mentioning have a tuner block those codes all together, but not sure if that is the best idea.

Any help would be greatly appreciated. I posted in the tech/performance section as well so apologize for the duplicate post, but figured this may have a different audience than that one. Thank you in advance!

pj-c7

Hi,
Just hit this today on my 09 A6 with A&A kit and meth. First time hitting them and just started researching....

Anyone want share their experiences? Replace sensor, trans, SOL

Thanks,
Pjs

VVVROOMTX

If i remember correctly i had these codes come up before and its due to a lager convertor. I just turned off then on and back to normal. Tuner addressed it as well and hasnt been back since.

VVVROOMTX

Nah, this is a common thing for an auto C6 with a larger convertor, stock 6L80 will stay alive at 7-800hp with a good knowledgeable tuner, trans cooler and overfilled on fluid.