RIP CM2250, 2013, 800,000km 20,000 hrs

[Hermjeji]

Been a while since this thread was discussed, after about 3 oil changes, got the overhead set completed on the fresh rebuild. Wanted to touchback on the SCR issues. I'm not electrically inclined, but it doesn't seem that difficult to test resistances etc. with the multimeter:

- Every two weeks or so the trucks derates due to SCR Operator inducement failure. I reset the fault codes, and the codes that stay consistently on insite are:

1. Water in fuel - shorted to high source - FC 3714
2. SCR Intake Temp - Shorted to high source - FC 3142
3. SCR Outlet Temp - Shorted to high Source - FC 3146

Here's a log of the SCR Intake temps when just idling and moving back and forth in the yard (-40F consistently with some jumps to a reasonable number?) During this time the dosing state went from initializing to priming to dosing, but the data didn't change (ie. still lows and one or two peaks).



Looking at the Engine Wiring Diagram on quickserve, there is a common 14-pin connector that the water-in-fuel and the intake-outlet SCR temp sensors connect to, which then go to various points on the ECM. How do I go about checking this connector? It looks to be in OK shape from the photos below. I don't want to be paying $100 an hour for someone to be troubleshooting this. Either I get it to a point where I can confidently direct someone or learn to do it myself. Also, on quickserve see SS below, the 14 pins on the connector are all used, but looking at the photo only 6 are used (position 9-14).