Gen 4 PCM in a Gen 3 car
02-08-2016, 08:56 AM
#1
Gen 4 PCM in a Gen 3 car I'm in the process of going through my turboed 2005 CTS-V again, changing some stuff, and I'd like to go to E85 and LY6 for this setup. I've already got the LY6 and harness and pcm, I was wondering if it was possible to run the Gen 4 pcm in a Gen 3 car and still have all the dash functions working. I'm under the assumption the Gen 4 pcm is probably better to tune on, because right now the 3 bar VE table in my PCM has like 3 psi graduations and doesn't live tune.
If at all possible, I'd like to keep traction control, the stock drive by wire pedal, electric fan controls, fuel pump control, all the dash gauges, and idiot lights, and the computer functions for fuel economy and stuff.
So I guess my questions are:
Is it possible to wire a Gen 4 PCM into a Gen 3 car and still have full functionality.
Is the Gen 4 PCM better in any way to tune than the Gen 3 PCM.
Would a Gen 3 PCM from another vehicle be better than the one I have, and allow a flex fuel sender, etc.
If at all possible, I'd like to keep traction control, the stock drive by wire pedal, electric fan controls, fuel pump control, all the dash gauges, and idiot lights, and the computer functions for fuel economy and stuff.
So I guess my questions are:
Is it possible to wire a Gen 4 PCM into a Gen 3 car and still have full functionality.
Is the Gen 4 PCM better in any way to tune than the Gen 3 PCM.
Would a Gen 3 PCM from another vehicle be better than the one I have, and allow a flex fuel sender, etc.
Last edited by killernoodle; 02-08-2016 at 09:06 AM.
02-08-2016, 02:12 PM
#2
It's doable but an awful lot of work.
The cluster will not work unless you install a CAN based BCM since it's the BCM who translates the high-speed bus to class-2 (low speed) data the cluster reads. Making a different BCM work in your car is going to be a wiring nightmare and you will have to sacrifice something.
Stock pedal will not work with the Gen4 ECM, it uses a different array of sensors and a TAC module. Gen4 systems don't use a TAC (built-in to the ECM). You need a Gen4 TB also.
The other modules will not talk to the ECM at all. If your car is automatic you need a TCM to control the transmission since the ECM only controls the engine.
It's much easier to use a Gen3 controller. With the proper OS it can do everything you need. RTT is not available in most OS. You don't need RTT to properly tune, it only takes a little longer.
My advice would be to stick with Gen3 PCM because it's easier to tune, it can accept any P59 OS from car to Van until you find exactly what you want. Your PCM is OK no need to change it, just flash the OS which does what you need, including flex fuel.
The cluster will not work unless you install a CAN based BCM since it's the BCM who translates the high-speed bus to class-2 (low speed) data the cluster reads. Making a different BCM work in your car is going to be a wiring nightmare and you will have to sacrifice something.
Stock pedal will not work with the Gen4 ECM, it uses a different array of sensors and a TAC module. Gen4 systems don't use a TAC (built-in to the ECM). You need a Gen4 TB also.
The other modules will not talk to the ECM at all. If your car is automatic you need a TCM to control the transmission since the ECM only controls the engine.
It's much easier to use a Gen3 controller. With the proper OS it can do everything you need. RTT is not available in most OS. You don't need RTT to properly tune, it only takes a little longer.
My advice would be to stick with Gen3 PCM because it's easier to tune, it can accept any P59 OS from car to Van until you find exactly what you want. Your PCM is OK no need to change it, just flash the OS which does what you need, including flex fuel.