Is this even possible?

[3100 MPFI]

I need to replace the tranny in my 1990 Grand Prix STE (3.1, 440T4, NON-TURBO).

I am planning on upgrading to a 4T60-E. NO BIG DEAL. Just swap it in, wire up the newer ECM, cahnge out the passenger axle, etc, and I can use any 4T60-E tranny up to 1993.

In 1994, they changed the tranny for the newer PCM.

Now, this is my question. I have a complete and FULLY WORKING 4T60-E that I took out of my totalled 1996 Grand Prix SE (3100 SFI). Is it possible to wire up the newer style 4T60-E to run on an older ECM so that I will not have to swap in a 3100, and rewire the car to 1996? I also do not want to do anything half-assed like splicing the 1996 PCM into the cars 1990 wiring so that it can work.

I know that I can PHYSICALLY use the tranny (it will drop right in), and since i have this one, I would like to use it if I can.

[sharkey]

i know for sure they changed the wireing pinouts between 94-96, so all you would have to do there is change the wires around in the plug. the only thing im not sure of is when they went to PWM lockup.

[Rhedalert]

'94+ 4T60e's don't have the shift "switches" for the PCM to see. Solenoids are operated the same between the early ones and the older ones though. I don't know if the PCM will throw a fit if it doesn't see the output from the switch when it shifts gears.

[3100 MPFI]

That is kinda what I am worried about. I know that if I don't hook up the PWM soleniod, then lockup will work like it does in the older cars (the PWM soleniod was getting flakey anyways, and I was just going to disconnect it before the pink car was totalled).

I am more concerned with the switches.

Looking at the wiring diagram, the 1996 tranny has the TCC, the PWM, 1-2 shift solenoid, 3-4 shift solenoid, and a trans temp sensor. (total of 7 wires).

So yeah, what I want to know is if I install this tranny if I will have issues with the switches that are not there. And if I have to replace the valve body, I might as well get a whole new tranny seeing that I can't use the valve body off of the 1990.

[Rhedalert]

That is kinda what I am worried about. I know that if I don't hook up the PWM soleniod, then lockup will work like it does in the older cars (the PWM soleniod was getting flakey anyways, and I was just going to disconnect it before the pink car was totalled).

I am more concerned with the switches.

Looking at the wiring diagram, the 1996 tranny has the TCC, the PWM, 1-2 shift solenoid, 3-4 shift solenoid, and a trans temp sensor. (total of 7 wires).

So yeah, what I want to know is if I install this tranny if I will have issues with the switches that are not there. And if I have to replace the valve body, I might as well get a whole new tranny seeing that I can't use the valve body off of the 1990.

Fuck the PWM solenoid. Disconnect that biotch. That's how I had it running on the Olds, and lockup is FIRM. Think of the PWM solenoid as taking place of the torque converter clutch apply accumulator, because that's what it did (my valve body has nothing in that spot, lol). And disconnecting it, the PCM can no longer control clutch "slip". Ah ha!! It's a beautiful thing.

I think the worst that may happen is you get a tranny DTC. Since the solenoids are controlled exactly the same, shouldn't be an issue, hopefully.

[3100 MPFI]

well. I had a crazy idea (as most with me are). I came across the TITLE to the car, and it has the WEIGHT listed as 3400. Sounds like a good idea to me. I have a COMPLETE 1996 Grand Prix DONOR CAR. I think I get a 3400, and swap it all into the STE.

The engine in the STE is getting tired anyways. I hate the fact that my GRANDMOTHERS Grand Am is faster.

[SappySE107]

We can fix that:P

[Daguse5853Z]

PWM lockup clutch was a bad idea. 3100mpfi, what color wires control the 1-2 solenoid and what color wires control the 3-4 solenoid?

[3100 MPFI]

I will have to get it later. My books are in my 1995 Cutlass Supreme right now, and I am working on it over at moms.

I am adding a few features to my 1995 Cutlass Supreme, so I am just leaving the books there. Adding in the HUD, second gear start, DRL's, etc.

I will go over there tomorrow, so I will look it up then.