1994 4l60 to 4l80

[Kujo3131]

Hello, new to the forum but have been lurking around for awhile so I figured I'd join.

I currently have a 1994 chevy 2500 (6 lug) that the 4l60 decided it was done. I also acquired a 1994 chevy 2500 (8 lug)with a low mile 4l80 that I plan on swapping in. I have everything from the drive shafts to the flex plate to the translines, ecm etc.

The only part I have a question on is I have found the info to move the pins at the trans plug and I know I have to add two wires for the vss. But I'm having trouble find a pin out for the tbi ecms. Anybody have any info on this?
Thanks in advance

You must be registered for see images attach

You must be registered for see images attach

 

[df2x4]

The 1994 GM factory service manuals for these trucks will have the PCM pinouts for sure. You can download them here for free:

https://www.gmt400.com/threads/88-98-service-manuals.43575/

 

[Kujo3131]

The 1994 GM factory service manuals for these trucks will have the PCM pinouts for sure. You can download them here for free:

https://www.gmt400.com/threads/88-98-service-manuals.43575/

Thank you for the link, I pulled the donor transmission today. One thing I noticed is the 4l80 has a iss sensor will I need to pin that in too in order for the ecm to operate the trans?

 

[df2x4]

Thank you for the link, I pulled the donor transmission today. One thing I noticed is the 4l80 has a iss sensor will I need to pin that in too in order for the ecm to operate the trans?

No problem, welcome to the forum!

Yes, you will need to pin the two ISS wires into the appropriate connector at the PCM.

 

[Kujo3131]

No problem, welcome to the forum!

Yes, you will need to pin the two ISS wires into the appropriate connector at the PCM.

Thanks for the welcome. One last question the 80 that came out has a vss sensor and there is one on the transfer case, where the 60 that came out only has one vss on the transfer case. Will I have to also add that second vss?

 

[df2x4]

Thanks for the welcome. One last question the 80 that came out has a vss sensor and there is one on the transfer case, where the 60 that came out only has one vss on the transfer case. Will I have to also add that second vss?

That I'm not sure about... Someone else here will probably know though.

I went from a 4L60E to a 4L80E in my '97 C1500, but that was a 2WD so I didn't have a transfer case. The only thing I had to do at the PCM was add the two ISS wires, all the other wiring mods were done at the transmission connector.

 

[1997]

Should help you out ....

TBI 4l60e to 4l80e

Finally had a chance to test drive after my 4l80e swap. Worked as I had planned. All gears work including OD. This was on a 95 TBI computer with a 7427 computer. Seems Like it may shift a bit early for my taste but that is probably due to my chip coming from a service box van and I have not...

www.gmt400.com

 

[Kujo3131]

Should help you out ....

TBI 4l60e to 4l80e

Finally had a chance to test drive after my 4l80e swap. Worked as I had planned. All gears work including OD. This was on a 95 TBI computer with a 7427 computer. Seems Like it may shift a bit early for my taste but that is probably due to my chip coming from a service box van and I have not...

www.gmt400.com

I had read this write up too, thanks

I don't know if I'm over thinking everything (which I've been kniw to do). In his write up he uses a 7427 computer. I have in my pickup is a 7060 and the donor truck has a 6395. ( different connectors) so now I've been reading everywhere is the proms are even swapable?