4l80e limp mode problem

[c5wagner]

I know how this sounds, but is it possible the wires are wrong between E8 and E9 on the pcm? Maybe the harness inside the transmission has them crossed........

[myburb]

It has been along time since I did anything inside a 4l80e but seem to remember the shift solenoids in the early ones and later (94-95) had different resistance solenoids. So the $31 and $OE might not be grounding them properly. You can manually test them by grounding. I think nothing grounded will give you second gear, 1-2 grounded will give you first, 2-3 grounded will give you third. It goes without saying but will say, don’t ground them both at the same time.

[brian617]

It has been along time since I did anything inside a 4l80e but seem to remember the shift solenoids in the early ones and later (94-95) had different resistance solenoids. So the $31 and $OE might not be grounding them properly.

Only the force motor (PCS) changed from 93 to 94-up

[lionelhutz]

Both shift solenoids grounded will put the transmission into 4th gear.

[myburb]

Both shift solenoids grounded will put the transmission into 4th gear.

Thanks for straightening that. As I typed was thinking of the old manual switching of both on for overdrive and then posted what I did. Must be age.

[ph4ze]

I know how this sounds, but is it possible the wires are wrong between E8 and E9 on the pcm? Maybe the harness inside the transmission has them crossed........

I rechecked my wiring and pinouts 10x's. And i just checked again just to be 100 percent sure, Yellow/black is in E8 and light green is E9. That is a good possibility that inside has the crossed. I know that its impossible to put the wrong connector on the wrong solenoid inside the tran y. Pretty sure i remember them being different shapes, so impossible to get backwards. Everywhere im reading it says that the solenoids are supposed to ohm around 17-25 ohms. Which mine are around 11.5. I feel either the internal harness is faulty or solenoids. But its a brand new internal harness and the solenoids were just replaced 2k miles ago. Its hard for me to grasp that they could both go bad that quick and at the same time.