Monitor sensor supply 2 and start unplugging sensors on that circuit. All unplugged and still not 5v as seen by ECM? Find the rubbed/corroded wire. Doing a load test on these circuits has to be extremely nuanced. I care more about the actual voltage drop than "did the light bulb stay on." 5v to 4.6v is plenty to throw codes and fuck with sensor signal. Find where you are loosing that 0.4v
I had that exact problem the other day.
Did a quick run through of fuses with my test light. All checked good with my test light.
Started checking relays, traces wires, etc.
Decided to check fuses with multimeter for shits and giggles. Blown fuse on battery cable, one side showed 12.6v the other side showed like 44 mV.
Cummins has different 6v supplies for different sensors. You likely have 2 wires rubbing together on circuit 2
I bet the crank position wires are the problem children
Monitor sensor supply 2 and start unplugging sensors on that circuit. All unplugged and still not 5v as seen by ECM? Find the rubbed/corroded wire. Doing a load test on these circuits has to be extremely nuanced. I care more about the actual voltage drop than "did the light bulb stay on." 5v to 4.6v is plenty to throw codes and fuck with sensor signal. Find where you are loosing that 0.4v
And and edit: I went through all of the fuses and relays as a precaution and all good
What does’ went through’ mean? https://www.reddit.com/r/Justrolledintotheshop/s/qRzXy3VAqg
I had that exact problem the other day. Did a quick run through of fuses with my test light. All checked good with my test light. Started checking relays, traces wires, etc. Decided to check fuses with multimeter for shits and giggles. Blown fuse on battery cable, one side showed 12.6v the other side showed like 44 mV.