bought a 2001 Grand Prix transmission with the overdrive out. I bought a used tranny for it. When I took the transmission out I noticed the main plug was different on the new one. Mine has a orange main plug and the one I bought has a green one and they have different pin configuration in it. Will it work? It also has a different module on the shift linkage, mine has two plugin'* and the one I bought has one. Any ideas? Thanks for your help

It will not. The pin out is different. Do you know what that transmission is out of? Year and make.

He said it was a 2001 Grand prix

Not with a different pin out. I do believe you can remove the side pan and swap out the wiring harness with your old one, and that should work. You can then also swap out the shift switch. You must keep things clean if your going to open up the side pan though. Also match up the number to make sure you do have the correct transmission.

Please post pictures. Orange/green..I've played with a good amount of transmissions and the main connector is all the same except for different pressure manifolds, and internal vs external pnp switches. But all the pnp'* that are external are always the same from what I've seen.

Ya, and the service manual only lists one plug diagram. Please double check the numbers.

There is technically only one wiring diagram in the book. But if you look closer you'll note some of the pins are for the internal pnp that some transmissions didn't get. Other pins are for the early model pressure manifold because it reported more pressures than the late model versions.

hey..speaking of......here'* a post that I did for a buddy that needed to put an external pnp on his newer model car when the internal pnp failed.

There are 5 wires that need to be worked with, If you look at the back of your main transmission connector it is labeled A through W. Wires F through J are the range selector input wires.
Trans connector

And from the back where the letters are located. The letters are small, be prepared to clean the back of this and look closely

Letters F through J are the ones you want. They should be the middle 4 (of 6) on the third row down. (My picture is of the transmission side, the letters are backwards on this picture.)

You will connect these four wires to a connector of an external range switch. Here is a picture of an external switch.

And the four pin connector and the place it connects on the range switch.


From the main trans connector
1. Connect wire F which is red with a black trace to wire D on the four pin connector that is black with a white trace.
2. Connect wire G which is dark green with a white trace to wire B on the four pin connector that is yellow.
3. Connect wire H which is yellow with a black trace to wire C on the four pin connector that is gray.
4. Connect wire J which is gray with a white trace to wire D on the four pin connector that is white.
Then connect a ground to pin D of the external range switch (larger) connector. On the 2000+ Bonnevilles there is a ground pack next to the shifter linkage on the transmission that could be tapped into for this connection.


Intall an external range switch on your transmission by removing the 15mm nut holding the selector arm onto the transmission.
Nut on selector lever

Nut removed

Lift selector lever out of way

Put switch on trans

For this to work properly there is a dot on the inner collar by the selector shaft of the trans that must be lined up with a line on the body of the external switch. Dot is being pointed to in the picture

Once these are lined up. Put in the two bolts and tighten. Put the selector arm back in place and the nut that holds it to the shaft, tighten the nut. Connect your two new external range selector connectors and the main trans connector. Turn the car ignition switch to on and review the dash to see that the gear selection is now appearing.