4L80-E Conversion Into a SB w/ SFI Vortec 5.7

[HotRodPC]

Yeah no doubt its a 4L80-E. So have you bought it yet? First things First Buy it.

There has to be a work around on this Pops. The Good news is, you're going into a Square with it anyway, and if this is out of a 91, which is TBI then' you're good to go using this harness. I was giving some thought to this earlier and thinking, at worst you'd have to change wiring harnesses in the trans. But, no you won't. The trick here is going to be, how to adapt the lack of the lighted range selector with the 96 ECM for the Vortech motor. I say the schematic you need to be looking for, is for a 91 Burb with a 4L80-E and see what was used fort he P N Safety switch without the range selector. It may very well be in the steering column just as it is for any other SB. Going to be interesting, but I'll assure with a few of us here, we'll get it figured out.

 

[HotRodPC]

None of which go to the PCM.

There would likely be a "PRNDL switch failure" code which basically does nothing.

Right, and with a tuner, that can be deleted as a failure code from the PCM/ECM also since he is going to be using a 96 Vortec Motor. What he is going to need to do is Use the Vortec ECM from that donor Burb, but reprogram it as a 3/4 ton so it will be 5.7 4L80-E instead of 5.7 4L60-E. Pops already knows he will have to change the pinout of the connector to the ECM, or find a 3/4 ton 4L80-E harness and hook to the ECM in place of the 4L60-E. Again, I don't think its gonna be that hard to figure out pops, and this is what I meant in the PM about deleteing the Range Selector. Deleting if from the ECM so it doesn't throw a code. It won't even read the range selector, or if it does, again, lets get the schematics from a 91 Burb and see what pins go where to the TBI ECM and translate that to the SFI Vortec ECM. With tuners today, I think this is going to be failry easy.

 

[oneluckypops]

ok There are infact Range selector codes they are Po7XX theres a few of them. But you are probably right in it not effecting anything. Heres something else that gets added to the equasion. The pressure switch in the valve body is what is sending the signal to the VCM selecting the gear state I beleive is all done manually thr the manual valve?

i got an idea though try this on for size. If I unplu the switch from my truck and jumper the C1 Terminal E to C1 terminal G (neutral safety switch) so the truck will start I should be able to tell if it will work or not just by going thru the gears and test driving it, Course I will go ahead and put the scanner to it and monitor the gear state in the computer to see what it says the whole time. What you all think about that plan?

 

[sandrock]

Trans range switch failures will give you some headache. The PCM needs to know when it is in park, and when it's in gear, because there are different idle requirements for both. There is also a different rev limit as well....

 

[oneluckypops]

Trans range switch failures will give you some headache. The PCM needs to know when it is in park, and when it's in gear, because there are different idle requirements for both. There is also a different rev limit as well....

While this is true. The Range selector doesnt communicate with the VCM EXCEPT for the Park and Neutral Position.

The Manifold Pressure switch is where the VCM learns the Gear state.
The VCM also receives Signals From the TISS letting it know that there is a Load increasing idle.

 

[sandrock]

I guess it depends on the PCM used. I'm basing my build off of the "0411" PCM, the same ones used in the late model Vortec 5.7 Express vans. It takes its info from the gear position encoder, and uses the MAP for load calculations. The PCM I use in my Bonneville is from a 2005 Impala 3800, and it uses a similar strategy.

My guess is you are running (or plan to) one of the "black box" PCMs, which is fine...in fact I was *this* close to sniping one from ebay. But the more I researched, the more the 12200411 made sense for what I wanted my build to have...namely, electric fans and more tuneability (and capability to run coil-on-plug later on).

 

[oneluckypops]

I guess it depends on the PCM used. I'm basing my build off of the "0411" PCM, the same ones used in the late model Vortec 5.7 Express vans. It takes its info from the gear position encoder, and uses the MAP for load calculations. The PCM I use in my Bonneville is from a 2005 Impala 3800, and it uses a similar strategy.

My guess is you are running (or plan to) one of the "black box" PCMs, which is fine...in fact I was *this* close to sniping one from ebay. But the more I researched, the more the 12200411 made sense for what I wanted my build to have...namely, electric fans and more tuneability (and capability to run coil-on-plug later on).

Cool someone with some of the same intrest as me.
yea i am using a 96 VCM and Original harness. Let me try to explain this a little Better.

When you select Drive on the Gear shift range selector sends power to the Instrument panel to illuminate the "D" in the dash. Also when you select Drive the manual valve slides in the valve body to allow fluid pressure thru the Drive portion of the manifold switch, depending on which port receives pressure determines what signal is sent to the VCM.

91-94 4L80E transmissions didnt even Have a Range selector switch, so if your using a 91-94 computer you do Not even Need the Range selector switch, because it is really just a neutral safety switch, and a fancy gear selection indicator.