Odd shift problem with 04.5 48re

[Speedo]

My wife's truck has a bit of a strange problem with the way the transmission shifts. There are times when it will hesitate shifting out of 1st gear once it does everything continues normally. If we let the fuel level get below 1/8 of a tank it will simply refuse to shift out of 1st until we
add fuel. if you keep your foot on the throttle when its low on fuel it will light up the hot trans light on the dash. Can anyone shed some light on what is going on and how the fuel level is making a difference with the transmission.

Gus

 

[cerberusiam]

Off hand, you have a bad connection or scuffed wires in the wiring harness. This could be in the harness or harness connector, or noise being dumped into the data bus somewhere at just the right frequency to interfere. Potentially, it could be the trans wiring harness internally or externally.

If you have not done so lately, replace the range sensor, gov pressure transducer, gov solenoid, and the VB wiring harness with OD and LU solenoids as a starting place. Age will deteriorate these items and finding the real culprit is near impossible.