The control system must provide a Run/Stop switch or a key switch to control engine start and stop.
The Run/Stop switch must be independently controlled from the ECM power supply;
The engine stop is realized by the Open/Stop switch open circuit, and the ECM power supply can be removed/closed after 30s of shutdown.
After the Run/Stop switch is turned off, it still takes a little time to process the data and save it (similar to the computer shutdown process). If the ECM power is removed/closed prematurely, the fault codes SPN627 and FMI2 will appear.
ECM lines must be installed in accordance with the circuit diagram
Any device capable of generating an induced electromotive force must be installed with a back EMF suppression coil connected to the ECM;
All welding work must be carried out after all ECM connectors have been disconnected. Welding will damage the ECM.

If you want to know more, please get help from support: https://www.dieselgeneratortech.com/support/

To anyone else who has the same issue, in this case it was the meter panal on the dash.

Thank you, I'll check

I found a Internal company Service Bulletin for this problem on trucks built from January 2007 to Present, may be worth a look:

Complaint: Intermittent to Hard communication codes such as, but not limited to PO3,PO4,PO7,FO4 & FO7

Cause: The diagnostic connector under the cup holder has a possible build up of corosion that is shorting across the CAN lines. This causes the VCM to see false communication signals and generate these codes.

Correction: Clean connector with electric parts and contact cleaner, Then remount under the dash in a horizontal position to prevent moisture from collecting in the boot, if corrosion cannot be cleaned out enough to prevent codes the wiring harness must be replaced at this time.

Thank you Edward,
I'm going to look at the dash 1st and check wiring /voltages along the way. The truck does have all hydraulic functions, perhaps they are seperate w/in the dash and VCM.

Does anyone out there have a P/N for the dash panal that controls the trany?

CAN= Controller Area Network. this is the standard that the computers and sensors use to communicate, sort of like how we cal the computer network in a building the LAN, or Local Area Network.
and to the second part of your last question, you are correct, but I will stick my neck out a bit, and say it's not really a "good general guess" and offer up it as an "educated by experience guess".

1st question, what's the CAN?
So a good general guess as to this problem would be;
a) bad dash
b) bad VCM
c) poor cabling/connection

if the vcm and/or ecm sees (or more accurately, -fails- to see) an incorrect or correct signal anywhere in the CAN, and both the dash and VCM are in the CAN, and the dash is where one of the 2 termination resistors in the CAN is: "P03= VCM Communication error P07= MP Communication error", {MP=Meter Panel} then the truck can do a number of things but I would not be surprised that not providing a signal to the transmission solenoids would be 1 of those things.
humor me, try a known good dash.

It does start in neutral and will not start in F or R. The park brake micro switch works.
I think I should check to be sure that voltage is making it to the VCM, what ever wire that would be from the F/R switch.

Neutral safety switch good?

I disconnected the connector to the soliniod and ran battery to the green wires and grounded the return wire of the soliniod. the truck moved.

The problem, is I'm not getting 12v to the green wire from the VCM, and probably no ground out of the VCM for the other side of the soliniod.

did you check to see if the trans. fwd/rev(on top of trans vavle body) solenoid is working? blown fuse any place/relays??




Meter panel(MP), VCM and ECM are connected each other and
their mutual communication works as a distributed control
system to control the truck. (This is from the book)

So a bad dash will not allow voltage to the VCM?

thru the FWD/Rev. switch's on the shift lever

How could a bad dash not allow for any voltage to the trany soliniod?

I think this is going to be a bad dash.

might have to have a laptop hooked up to it and looked at that way to see what is going on. I have ran into these before and was a loose connection on the "computers" Did you check the one(computer) that is under the foot step? doubt its a temp sensor or would code for that. Check to make sure your relays are good??

Yes I checked the relays and swapped them around. I also inspected the connectors and pins. Could the CPU be broken, or the pulse generator that is attached to the side of the trany, or could the temp sensor be bad?

P03= VCM Communication error P07= MP Communication error
Check all Connectors on the controll boxes,they get loose sometimes(have the flip over thing that is supposed to keep them connected,also check they relays in the blue rectangular boxes to make sure they are tight in their sockets.