I don't know if this has already been asked, I am new here, and it seems some time back all the old threads on the board were lost in some sort of catastrophic incident.

I recently purchased a 2005 Colorado, and the way it chooses its gears is really kind of annoying. It stays in first way too long when accelerating, and hangs on to 4th (over drive) way too long when starting up a slope at under 50 mph.

In fact, on level ground, if you hold the engine at 1500rpm in 1st, it will not shift up to 2nd, and even at 50mph, if you punch the gas, it will return to 1st momentarily before it realizes that about 60 is redline. And if you hold it at 1500 rpm in 2nd, it will upshift to 3rd, if you hold the rpm at 1500 in 3rd it will upshift to 4th.

Is there any way to adjust this behavior?