Transmission doing weird things

i just bought a 2008 double can long box trd sport Tacoma about a month ago. I bought the truck a week before moving and towed my loaded down prelude on a car dolly plus had the truck fully loaded 800 miles. No problems what so ever. Then a couple weeks ago the battery got low so I replaced it. Now my truck shifts a little weird. It only does it when it is cold. Usually it is the 2-3 or 3-4 shift around 35 mph. The transmission will let go like it is slipping between shifts then suddenly shift into gear harder than usual.

 

Can't think of anything from that to point to an obvious solution.

I'd recommend disconnecting your battery for about 15 minutes or so and let everyhing reset.

 

I have a transmission flush scheduled. I'm hoping it is just dirty fluid clogging a valve causing the odd shift. Once warm it drives fine and it only seems to want to do it once then it's fine after that. Always in the first couple miles.

 

I have put about 500 miles on since replacing the battery. How long does it normally take for the ecu to reset.

 

Trouble codes and such can go by key cycles(you don't have a code or light), does it see the fault every time from ignition off to drive mode or was it a one time fault.

Battery disconnected usually takes 5-10 minutes to clear. Usually recommend 15-30 minutes to be safe.

The battery swap is the only common denominator linking the two from your description. That's the only reason I suggested such.

 

I also forgot to mention I recently also replaced my spark plugs with ngk Iridium ix plugs. Now my transmission did shift a little weird before the battery change, but non of this righ rev/slip lagged shift thing that it is doing now. It also seems like it is getting worse but only does it once then fixes itself. Would the plugs have anything to do with this? I do about 50-70% highway driving and am getting high 19's for fuel mileage. Everything is currently stock as far as lift, wheels and tires