Originally Posted by TRD_Tundra
I'm thinking it's due to not having the TRD-Reflash
You would be thinking right. When we installed the Supercharger on a 4x4 2012 DC back in Dubai, we choose the cheap option of using the unichip without the TRD flash. It shifted like yours did. The shifts you are experiencing isn't like the ones a shift kit would produce and is by far worse than with only the smooth shift of the TRD flash.
We solved this problem by simply installing the TRD flash. That's where your problem is (being a Flex Fuel).
You have two options that I could think of:
1- Tune the transmission using a stand alone like you did the engine.
2- Or, replace all the ECU components with a non-flex fuel Tundra's. That would include an ECU, a matching complete harness, and a matching key fob. If any of those don't match with each other, the engine won't start and the ECU would go into theft mode disabling the fuel pump. This would have costed us more than $1500 in Dubai including labor, and only one shop was willing to do it.
The reason I know about this, is because we were not able to install the TRD flash on the truck at first. We used an 08 ECU that was laying around and we were able to flash it but the truck wouldn't start (ECU not matching the key and harness). Which made us think the 2012 ECU we have isn't programmable.
That's when we went to the other shop to reprogram the 08 ECU into thinking it was a 2012 by changing the VIN number on it. Before the guy at the shop could start reprogramming, we figured out that +2010 Tundra's use the 'G' security system which any of you with a +2010 Tundra will find carved at the lower part of the key. All other Tundra's (2007 - 2009) will find a small dot instead. So he told us to replace the whole ECU harness with an 08 or it won't work seeing that the 'G' system doesn't accept donor ECU no matter what.
After all that trouble, we tried another shop that offers the TRD reflash as we thought the previous guy who tried to do it had an outdated programmer or something... and it worked! lol simple as that.
In short, Stand alone trans or a completely new ECU system from a non-flex fuel. Hope this helped