4T60E Swap 93 GP to 95 Lumina

[gcarson114]

We swapped a 4T60E trans from a 93 Grand Prix into a 95 Lumina. Reverse works fine but trans only works in 2nd when place in drive. We suspect the wiring is not the same even though the connector fits. Does anyone have any experience with this swap and even better a wiring diagram? George

[napatiger]

Cool, you figured out how to activate the 2nd gear start.

[sharkey]

does it start off in 2nd gear then shift to 3rd, or does it just stay in 2nd gear???

i beleive i have read about the wiring being changed sometime in that year.ill try to see what i can find at work tomorow.

[gcarson114]

It starts out in second and stays in second.

[gcarson114]

A solution

Since we had no meaningful response to our questions we decided to try and solve it ourselves. We went to our local library which has access to Mitchell on Demand and retreived a couple of wiring diagrams and Transaxle Check Flow Charts for the 93 Grand Prix(4.3 engine) and the 95 Lumina(3100 engine), both 4T60E transmissions. The Lumina trans has a pressure sensor in the trans while the GP does not. The Following is how we made it work for us:
Step 1- After installing the GP trans in the Lumina remove the seven pin transaxle connector. Looking at the connector the pins are identified starting at the top and going clockwise as E, D, F, A, B, G, and C. You need to ask some GM engineer why this order???
Step 2- Cut or remove the wires at positions F and G. These were for the temp sensor. The pins can be removed by first taking off the plastic retainer and then inserting one leg of a small cotter pin into the small opening on the outside of the pin hole. This will release the pin which can be removed through the backside of the connector.
Step 3- Move the wire in position A to position F.(solenoid A)
Step 4- Move the wire in position B to position G.(solenoid B)
Step 5- You will need another pin with wire for this last step. We had an old wiring harness around that we used or you could use the wire and pin that you removed from position F or G. This wire needs to be connected(recommend soldering) to the wire in position E to provide power for the TCC.
Step 6- Insulate the cut or removed wires and plug it into trans and it worked for us.
If you have any questions or comments you can contact me at gcarson114@sbcglobal.net.