4l60e to 4l80e Swap

[boostedc10]

Guys,
I saw this question posted in another thread and figured I would put up a quick how to on swapping a 4l60e to a 4l80e. It seems this comes up from time to time, and may have already been done in the past.

If so feel free to delete this thread, if not feel free to add to it as I am sure I will miss a thing or two.

To be clear everything I am talking about is assuming you are using a harness that was originally set up for the 4l60e with the blue/green or blue/red ecm connectors.

The procedure below will require no new wires (You will use the 2 wires not needed out of the main transmission connector) and only require a ISS plug (Delphi 12162194) and two terminals (Delphi 12124075 or 12191054)



On the main transmission plug (See image above) you need to move pin U to pin S

Next remove terminal T from the connector.

Now that you have pin U moved to pin S and have also removed pin T you will have 2 wires hanging loose from the connector. These 2 wires will be used for the new Input Speed Sensor.



Pin T will go into pin A on the ISS connector and your other free wire to pin B

Last step is to swap these wires at the ECM. Pin A from the ISS must go to pin 22 of the green/red ecm connector and pin B to 23 of the same connector.

NOTE: I located the ECM side of them with a DVOM and dont remember the original location of the wires, so if anyone has this info handy it would be good to add. The 2 terminals would be the one for the 3-2 shift and the other is TCC on/off for the 4l60e.

Now for the converter side of things. You have a few options. You can get the 4l80e flex plate (p/n 12551367) and spacer (p/n 12563532)or if you are having a converter built you can ask them to use a front cover that fits the 60e flex plate.

NOTE: Stock 4L80e covers use 6 converter bolts and the spacer is needed to ensure the starter engages correctly.

Additionally you will have to have a segment swap done on the ECM to allow the 4l80e to shift correctly. This is very simple if you have access to HP Tuners or EFI Live. If not you will have to have this done by someone with access.

Think that pretty much covers it, and if not I am sure someone else will chime in.