Had this happen to me on the way in to work this morning.

Was cruising along behind some slow people and was just coasting, not really aware of any of the conditions but probably around 25-30mph. I went to accelerate lightly and get this odd stumble where the trans has no frickin' idea what gear it wants to be in. Within a matter of 2 seconds it shifted down, it shifted up, it shifted back down, it shifted back up, all continuously. Was quite jerky to say the least. I have noticed this before and it only seems to happen when that assinine cold weather shift pattern is in operation.

Is this something within the programming itself, or something mechanical? God I ******* hate electronic transmissions <img src="gr_images/icons/mad.gif" border="0">

 

Sounds like that PCM re-flash I was telling you about?

Questions;

Does the 5.3 come with the electronic throttle control like the 8.1's?

If so, was it (the engine) still relatively cold?

If so, you may be suffering from the "cold hesitation" issue that 8.1's seem to have when cold. There is also a PCM re-flash for this.

 

Lane

Pretty sure the 5.3 throttle is cable actuated. The engine was warm, not full operating temp, but probably around 180* or so and had been running for at least 10 minutes. I think I will look into that PCM reflash as this trans does seem to do weird things and they all seem to be related to kickdown/shift issues.