Im trying to figure out some stuff about this wire. Im pretty sure this is the wire that makes the pump work the way it does (utilizing the sensors, etc.). My question is is this wire taking a signal from the ecm to the pump or vice versa? What sort of integrity test can I do using a DMM for this wire?

What wire are you talking about?

 

 

are you talking about the black wire and the white wire?  from the ecm to the vp44?

 

 

 

If so those wires talk VIA canbus so there isn't much you can do with the DMM to test them other than look for continuity.  

According to alldata its the Dk Green. So on ur picture there it says fault sync. I dont know anything about the datalink stuff. I know there is no way of testing that (i think). But I guess it the fault sync wire. Is that the signal wire from the ecm that controls the timing via MAP and IAT signal? And is there a way to test that one?

No all fueling commands are sent Via canbus messages.  

 

The ecm requests a timing and fueling then the VP44 decides what to do with it.  That is all done via the 2 canbus wires.    The VP44 PSG wears the pants in the relationship.  All the ecm can do is request for a given amount of power.

 

I am not sure what the green fault wire is for.  Likely a way for the vp44 to tell the ecm that there is an issue with the timing or fueling solenoids.

Okay I think im overanalyzing here. Addictive mechanical mind...So all commands to vp44 are from ecm. No way to really test it other than the sensors or hot wiring it correct?

Yep the Cummins ECM acts as the translator between the vp44 psg and the sensors.   The vp44 psg controls the fueling and timing on it's own based upon the requests from the ECM.  

 

 

its a pretty nifty system considering what they had to work with back when.

 

 

This is why we have the 65 hp limit on canbus boxes.  the ECM can request anything for HP levels but the PSG will limit all commands to stock + 65 hp based upon its own internal fueling software limits.  hence why we wiretap, effectively cutting the PSG out of the equation.

Edited May 17, 20168 yr by Me78569

10-4. So would that green wire be link the signal for the datalink connector to show a code then? jw.

Edited May 18, 20168 yr by Cumminz

I honestly dont know.  I am struggling to understand the point of the green wire since error codes should be able to be triggered via the canbus messages.  

 

The big bosch riddle in the PSG.,