Question for you 24V guys.

The ecm controls the engine timing, vp44 timing and everything else that has to do with the engine running properly. The pcm controls the alternator voltage output and the electrical signals going to and coming from the sensors and feeding that information back to the ecm. So, to answer your question, if you want the truck to run,it has to have an ecm that is the same trans type as the one it is going in. As for the pcm, you can install an external voltage regulator and wire it to the alternator and not worry about anything else, other than check gauges light and gauge issues and lights pulsing.
 
QUOTE=BRE;2019727]78 actually, it's way rougher than it looks.[/QUOTE]

Yeah those body styles like to rot. My dad has 78 Z28... we were going to restore it back to factory until we tore it apart and saw how bad it really was, now it will be a drag car one day if we ever get back to that project.
 
Flatblack79 said:
QUOTE=BRE;2019727]78 actually, it's way rougher than it looks.
Click to expand...

Yeah those body styles like to rot. My dad has 78 Z28... we were going to restore it back to factory until we tore it apart and saw how bad it really was, now it will be a drag car one day if we ever get back to that project.[/QUOTE]

Mines just a play toy!
 
jesnic said:
The ecm controls the engine timing, vp44 timing and everything else that has to do with the engine running properly. The pcm controls the alternator voltage output and the electrical signals going to and coming from the sensors and feeding that information back to the ecm. So, to answer your question, if you want the truck to run,it has to have an ecm that is the same trans type as the one it is going in. As for the pcm, you can install an external voltage regulator and wire it to the alternator and not worry about anything else, other than check gauges light and gauge issues and lights pulsing.
Click to expand...

Good info here thanks. :Cheer:
 
jesnic said:
The ecm controls the engine timing, vp44 timing and everything else that has to do with the engine running properly. The pcm controls the alternator voltage output and the electrical signals going to and coming from the sensors and feeding that information back to the ecm. So, to answer your question, if you want the truck to run,it has to have an ecm that is the same trans type as the one it is going in. As for the pcm, you can install an external voltage regulator and wire it to the alternator and not worry about anything else, other than check gauges light and gauge issues and lights pulsing.
Click to expand...

^that is partially correct.

The ECM runs the engine, in a 98-00.5 they dont give a damn about the truck or the transmission. 00.5-02 autos have a torque management that needs to see vehicle speed, straight shifts also need it but I am unsure if it will defuel with no speed signal. The ECM reads the sensors and sends the info to the cluster via the can bus, nothing on the truck controls the engine. (edit: the can bus may go to the pcm first)

The pcm does control the alternator, as said it can be bypassed.



Flatblack79 said:
Wonder if i should jump on this. It needs to be rebuilt but i could go on and do what i want to it... Decisions decisions

24 valve cummins motor
Click to expand...

That looks like an 01 engine, electronic wise the VP and APPS are the only things that will work, few other minor sensors.


For what is is worth, I have never driven a ppump engine that had the grunt of a VP when towing. They are really a great setup under 500hp.
 
Last edited:
The the reason id like either a 12v or to p pump a 24v is because im not comfortable with jumping head first into something that i have absolutely zero knowledge/ experience with (efi) All I have experience with is carburated gas engines.
 
You must log in or register to reply here.
Back
Top