4l80e reverse only when unpluged
#12
so to day i go and cut the wires one at a time to the pressure control soleniod nothing still no reverse tryed cutting the wires to the pressure switch manifold still nothing. i do not understand why i have great strong reverse when i unplug this thng but nothing plugged in. does the pressure switchmanifold have anything to do with the shifting? i know on the wire diagram it shows P R N going to it im thinking that stands for park reverse and neutral?
#15
found this on a site
"If the control module senses a speed reference greater than 8mph during the shift into reverse, it has the ability to prevent the shift from happening. That being said, it is a very simple test to eliminate the electrical part of this one. Unplug the electrical connector to the transmission (this will force a fail-safe shift pattern eliminating the computer's ability to prevent the shift) and see if the reverse shift comes back
Answers to the test results of case connector unplugged:
•Reverse works: check for speed references to control module.
•Reverse fails: on to the mechanical test"
so does anyone know how to test the speed refrences t control module?
"If the control module senses a speed reference greater than 8mph during the shift into reverse, it has the ability to prevent the shift from happening. That being said, it is a very simple test to eliminate the electrical part of this one. Unplug the electrical connector to the transmission (this will force a fail-safe shift pattern eliminating the computer's ability to prevent the shift) and see if the reverse shift comes back
Answers to the test results of case connector unplugged:
•Reverse works: check for speed references to control module.
•Reverse fails: on to the mechanical test"
so does anyone know how to test the speed refrences t control module?
#16
You have a internal problem. I would have your other transmission repaired. There are so many possibilities of what could be wrong. Short of taking it apart there is no telling what's wrong. Sorry I can not be more helpful
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