AT Upshift Issue
 

Just yesterday, I noticed this oddity: my car will not shift up from 3rd gear. 1st to 2nd works as it should, as does 2nd to 3rd. Revs going up and up... and no upshift from 3rd to 4th.

Tried going to manual mode and doing it -- no dice. The "up arrow" is there, on the dash, suggesting that I can upshift, though nothing happens when I tap the up paddle.

2 years old / 24k miles, this is my first seemingly significant issue. I don't drive the car particularly hard, occasional fun, mainly a commuter. Guess its time to bring to the dealer!

Any initial thoughts?

Take it to dealer ASAP :)

Update: Drove it home from work this morning (only mode of transportation). Started it up and let it warm for a minute. Shifted into manual mode and cycled through the gears up to five, without issue; shift into 6th was quite jerky @ 45mph, and the car immediately spit a CEL and an ABS light. Had to stop at a light, from which point forward car only shifted up to 3rd.

Also, upon release of gas pedal while cruising in 3rd, RPM dips very low, almost like the car moves out of gear when cruising. Upon gas pedal depression, RPM lurches way up once again.

Issues really out of the blue, though I did have a 25k mile service 3 weeks ago.

Yup, I'd take that in asap

Update: My dealer is closed today. Went to an Advance Auto Parts to check the codes. Issues with the shift solenoids, not good. Upon searching, I don't think anyone else has had this issue on the forum.
http://i.imgur.com/ApmnhTb.jpg

http://i.imgur.com/S8Ad8EK.jpg

http://i.imgur.com/ESUMOyz.jpg

http://i.imgur.com/LehIEbi.jpg

Is this something that is easily repaired? Or will the car be in the shop for a while? Thanks for any thoughts.

All these codes sound expensive.

Looks that way. Thankfully, should all be covered under warranty.

Just in case anyone cares or encounters this issue themselves, here was my resolution:

"Multiple shift solenoid faults set from mismatched actual gear position and commanded shift position. Freeze frame data does not show this condition. Cleared faults and test drove vehicle under inspection procedure parameters. Transmission can be commanded through all 6 gears up and down and ECT ECM shows correct gear on data list. Cannot reproduce condition originally causing faults. No damage or leaks from transmission found."

tl;dr dealer claims it was a fluke

Interesting..let us know if it happens again. Have not read of many auto transmissions issues on the forum...certainly nothing like this so maybe it was "a fluke" like the dealer stated