Mine threw an APPS code and ended up replacing APPS. There are two designs early and late. Early is mounted above injection pump and late is mounted below battery tray. Early model is more expensive than late model probally by about $100 or so at dealer cost. Picture that redracer put up is for early model. To ease in finding one at a cummins dealer ask for a bell crank or a bell crank sensor. When I asked for an APPS at a cummins dealer I got the confused dog look.

 

Alright so, I tried the battery disconnect again. Following that I cycled the pedal and key. Holy crap, it worked. The code was still there when I cranked the truck but after it warmed up for a few minutes it turned off and now shes running like she should. I did talk to my truck for a few minutes telling her i just wanted to help. Call me crazy, maybe that actually helped. jk. thank you everyone for the help. Hopefully this wont be a fluke and turn right back around on me, I am moving and kinda need my longbed. thanks again everyone.

 

To "APPS isn't it. Maybe the ECM"

So I put the new APPS in and it didnt' change anything. After screwing with it I see I'm getting 5 volts on the supply connector (APPS wire harness). From reading it seems the one code will throw if I get more than 4.8.

Again after fiddling with it and even tapping the ECM with a rubber hammer. I know, it was something I read. Said while running if a tap changes how it ran it was a dead ECM.

Anyway after all that I'm now throwing codes.
P0514-battery temp
P2123-APPS sensor 1 high voltage
AND NOW
P2509-Loss of voltage on the ECM (I disconnected it)
P2122-APPS sensor 1 low voltage
P2127-APPS Sensor 2 low voltage

I'm not sure if the last 2 are from me testing with the APPS unplugged. The BS code reset procedure of disconnecting the battery for an hour doesn't work. And I'm tired of driving to the Auto Zone today.

I'm looked and looked and see no broke wires. Everything is still in the factory wrap and I figured I'd do more damage trying to open it up. I pulled connections and WD40d them. The 2123 code and 0514 will not clear. Scanner says it clears them but they are immediately back as pending on the scanner.

I'm looking at ordering a ECM now. Do these really go bad? I thought I read somewhere they don't. I know I could take it to the dealer. I'm thinking ECM only because the one part didnt' make a change and the several of the codes point to APPS, the wiring or ECM.

 

opinions?....