Found some old post about this but nothing up to date .
My 2013 A6 has this problem .
2yrs ago driving in warm to hot weather after 5plus hours the trans started to disengage, slip , not shift ,etc . throttle worked but no trans. none of the shifters worked , paddles or floor mounted . NO indications on the DIC . I let the car set for about 15 mins and it worked fine . took it to the dealer and they found nothing .
Now a cple days ago on a trip to Yosemite it happended again . nothing on the DIC and my scanner showed NO codes .
Anyone having these type of problems ?

 

It would be nice to know the A6 AND engine temps at the time of failure. What was the outside temp?

The LS3 will start deactivating cylinders and throw codes when it gets too hot. What happens when an A6 gets too hot? What does it do to protect itself? And why no codes?

I found a tsb at this site: http://www.chevroletproblems.com/tsbs/Corvette/2013/
Description: GM: THE TRANSMISSION IS SLIPPING OR HAS NO FORWARD/REVERSE MOVEMENT. *RM UPDATED 4/16/12. *PE UPDATED 6/18/12. *PE UPDATED ON 7/09/2013. *KB
May 1, 2013 NHTSA Reference: #10039489 TSB Reference: #PI-0488
I don't know if this relates to your problem.

What did the dealer do to check out the problem? It seems the tranny has to be really hot to fail. How did they simulate this.

Has the tranny ever worked fine when in hot weather on steep hills?

You might want to discuss this with a high end tranny repair shop.

Really strange that it failed, worked for 2 years, failed again, and worked again.

You are still under warranty. You have to get the dealer to find & repair the problem.

Sorry I can't be more help.

M...

 

After the warranty is up I would invest in a trans cooler. As mentioned in the above post check the trans temperature ,oil temp and outside temp.

 

there are a lot of A6's out there running in hot temps with the stock cooler ..... if i was a betting man its not electrical as its not throwing a code .... sounds like something mechanical sticking .....

Dave

 

If you don't habitually scan the DIC to view current conditions, it's quite possible the problems are a result of overheating. There is no over-temp message until the fluid is at least 266 degrees, but you can seriously affect the fluid's capability to function well if you run it above 240 for extended periods or do it often. Yosemite and other mountain roads put a good strain on the trans and tend to overheat the fluid anytime the TC clutch is not locked.

What is your current mileage and have you ever changed the fluid?


BTW, your profile is outdated and still shows a '66.

 

Thanks for responding , I still have the '66 but need to update a photo of the 13 .
The coolant temp the first time this happened was about 220 if i remember right , the trans fluid was very near the same . This time the coolant temp was about 180 and i dont know what the trans temp was . I have just under 29k on the car and haven't changed the fluid .
Because it isn't throwing codes I suspect it is something mechanical or fluid . I don't suspect a trans fluid change and flush is something i can do on this car myself .

 

Well, it happened again , drove it to Lake Tahoe and weather in the low 80's , up hill , trans attempts to downshift from 6th to 5th and slips , car slows to about 40 , I give it gas , rpms go from about 1000 to 3000 with NO change in speed, No codes , no messages on the DIC . engine temp and trans temp below in the 190 range .
This always happened going up hill until on the way home . Flat freeway ,cruise on , going 80 mph, take cruise off to slow for traffic and , trans starts slipping , did it about 5 times in the next 30 minutes . When it happens i just have to keep slowing down and giving it time to engage .
Looking for a TSB to refer to at the dealership but can't find a good site to look up TSB's .

 

Have the dealer do an adaptive relearn reset on the trans ....sounds like a TCM issue
Dave

 

I just made an appointment for this wednesday . I ask them to do the adaptive relearn .
Thanks Dave

 

If your car isn't your daily driver, or you can stand to have it laid up for a month, or if you feel like a serious road trip to Ossining NY (just north of NYC), you might consider having Chuck Mosello at Corvettes of Westchester (Chuck/CoW) rebuild it with one of his A6 transmission kits. This package is relatively new, and something Chuck worked out with vendors he's seen at the annual SEMA show in Las Vegas.

Pulling and shipping your A6 to Ossining would be a major bother. An extended road trip to Ossining would be quicker, cheaper, and probably a lot more fun. Watching Chuck work is a hoot all by itself.

If ever my A6 starts to misbehave (it has 120K on the clock), I plan on making that road trip myself -- for the third time. (The first two trips were for an E-Force supercharger in 2012 and last summer for a new DeWitt's radiator and NPP exhaust system.)

Just my $.02.

 

Always a pleasure to have Doc around!

Chuck CoW

 

Sounds like you are still under warranty? Find another dealer worth their salt.(I realize that may be tough) My God what did they do, start it up and run it around the block? Did they inspect the tranny, as they should? Got to jump on someone's *** if it's still under warranty. I would raise hell with them and the GM reps till they found out what's wrong. Something is wrong that needs to be fixed, and don't mean buy a cooler after warranty and still have a pile of problems. JMO Some dealers suck, correct that, most dealers suck when it comes to Corvettes especially and service.

Could only get one out of three in my area to give me the time of day. Finally had shocks, alignment, and recall fix at one and they didn't even know how to lift the car. Lifted it on the rocker panels with no pucks or even rubber. Scratched them all up and then tried to blame it on me. Broke one door sill, had a plastic heat shield fall off and get run over and they couldn't even find the part. I had to google till I found it for them. Brought it back for the parts they broke and they admitted they had to redo the alignment because their machine was all f&^%$ up, after I had already put over 4K miles on new tires on a trip.

Sorry about the Rant, but good old Ask what's his name and GM ought to rethink their dealer training and responsibility on Corvettes. Used to give them the benefit of the doubt but not any more.

 

nowucme - Sounds like we live in tha same area ! This will be the 3rd dealer ive taken it too.
Hoping the .3rd time is a charm while still under warranty

 

Also having slipping problems. Car went into limp mode. But was able to drive after shutting down and restarting. Slips when shifting into 3rd. Any recommendations for a shop in the San Diego area?

 

To start off, has the transmission fluid level been checked?
Those symptoms that are being mentioned are often caused by the control solenoid valve and transmission control module (TCM).
The connectors for the PCM can be checked for:
Inspect the control solenoid (w/body and TCM) valve assembly connectors and pins (2, 3,
4) for the following conditions:
Damage
Bent pins
Debris
Broken retaining tab

If those connector pins are OK, then the internal sloenoid valve will have to be performance tested using the GM scan tools to determine the issue.This info is in the service manual. The test procedure is explained and mentions various problems that can exist with the TCM and control solenoid.
I'm not sure if it any use, but PM me you e-mail and I can send you the A6 transmission Service manual section (PDF)

 

Or it could be something as simple as SHIFT FLARE that almost affects EVERY A6 in all GM cars and trucks that use it , not just the A6 in a Corvette
The adaptive learning logic in the A6 is crap ...

Take it to a trans shop or a dealer and have them reset the shift ADAPTs and do the relearn procedure before you shoot the parts cannon at it

Because of the heavy Atlanta traffic, I lived with the 2nd to 3rd shift flair the whole time I had my C6. Every once In a while i would pull out my trusty TECH ll and reset the adapts and it would be good for awhile ..

Even my new C7 with an A8 sometimes feels like it slips on the 1st to 2nd shift when going real slow but I have been living with it
Dave