2008 G35 auto transmission problems

[twropn]

08 G35 journey (paddle shifters self installed years ago)

I downshift a lot comming off of freeways (usually use the shift knob not the paddles) and the other day as I shifted down from 3 to 2 and the engined revved it started to slow then the gear inicator in the dash went to "D" and the car had clearly upshifted (wasn't decelerating as fast anymore/rmps fell). I flopped the knob back to the D position and then back to the manual position and nothing, no change on the dash indicator, and the car wouldn't shift up or down via using the knob. The paddles worked thought.

This happens for the 3-4 shift now too. However when I downshift with the paddles the car won't jump back to a higher gear.

Thoughts?

No mods. 120K miles (its probably due for a transmission service)

[audtatious]

Yeah, that's weird. Have you tried a complete reset? I'd disconnect the battery and let the system clear and see if that solves it.

[joe603]

That's an odd one...The dealer may charge you because you added the paddles. I would suspect it has something to do with that...

[audtatious]

I disagree about the paddles as they don't allow you to do anything different than you can do with the shifter itself

[joe603]

But it's a mod having to do with the transmission...had to wire it "in" somehow...

[audtatious]

The harness is already there, it's just plug and play.

Mike has done this recently to his G37 and as soon as it's sent I'll be posting a how-to.

[joe603]

Really! Did not know that. ECU reset yet?