auto trans ?

[george_01]

When cold, below 30, my trans wont shift out of low gear. Even after driving for awhile. When warm out side it shifts OK. Had trans flushed and filter changed. Still wont shift when cold. Any ideas or thoughts will be appreciated. Thanks, George

[Dimsdale]

While I don't notice this so much on my 4L80E, my wife's truck's 4L60E is programmed to stay in lower gears longer and will not do a TCC apply until the tranny temp reaches a certain level.

Perhaps there is some of this effect in your trans, or it is screwed up some way. Given that your problem seems to be temperature related, maybe there is a tranny temp sensor problem.

Hope this helps some!

[Barry Nave]

Coolent temp sender to pcm could have the pcm fooling with the trans.

[JohnC]

Check the voltage to the trans fuse whe cold before starting. If it is low the trans will fail its system check and go into limp mode, which is 2nd gear only. The cause is often the ignition switch. It often shows up first in cold weather, but eventually goes full time.