Originally Posted by 76LQ9TA
I have the switch from the 4L60E trans. So they are interchangable? I was going to run the second VSS to the PCM. I don't think there are currently pins in those locations. I know about switching the 2 wires on the circle connector. I thought I would not use the other two on the 4L60E that aren't on the 4L80E connector. I guess I've got some more homework to do. The dealer faxed me a schematic for the 4L80E trans but the wire colors aren't matching what I see on the harness. That is why I started this thread. Do you know the part number for the pins in the PCM. I have to buy one to control the electric fans. Thanks for your help.
I believe the 60E and 80E switches are interchangeable, but I would have your local dealer verify that.
There are 3 wires in the circle connector. If I remember correctly, you need to move the wire from pin U to pin S. Pin T is not used for the 80E, and the wire that came out of Pin S isn't used either, meaning you have 2 extra wires already in the harness. Those 2 wires already terminate at the PCM, but go to the wrong spots. I think they both need to be in the Blue connector for the ISS, but 1 is in blue, the other in red.
Don't have any clue what the pin part numbers are. Jarred @ Current Performance Wiring (S10 wiring harness specialist) made my harness up, so I didn't have to buy any of those bits and pieces. Maybe somebody else on here knows the part number for the pins.
And that Second VSS as you called it is measuring input shaft speed, so that the trans controller can detect clutchpack slippage (by comparing ISS reading with VSS x gear ratio) and TCC slippage (by comparing crank sensor to ISS).