01 5.3 4x4 irrattic shifting

[rwwiefer]

New here. I have a 2001 5.3 extended 4x4 5.3.
lately if I jump on it, it seems to stay in the tow/haul mode. The idle remaining about 1100. If I am just running 40 in town I have to actually lift to get it to shift up to either 2 or OD. If I stop and shut off the truck and restart it, its like nothing is wrong until i accelartor enough to cause the tranny to down shift then its stuck in the high idle again.

 

[rwwiefer]

codes

It's NOT showing any troubles, No check engine light has come on.

 

[Molson02536]

New here. I have a 2001 5.3 extended 4x4 5.3.
lately if I jump on it, it seems to stay in the tow/haul mode. The idle remaining about 1100. If I am just running 40 in town I have to actually lift to get it to shift up to either 2 or OD. If I stop and shut off the truck and restart it, its like nothing is wrong until i accelartor enough to cause the tranny to down shift then its stuck in the high idle again.

Start with the simple and clean your throttle body making sure you pay attention to the Idle Air Control Valve passage way.

As for the transmission, Check he fluid level and the TPS for a smooth and linear electrical response over the entire range of motion. If not, replace.

Good luck and keep us posted.

Molson02536