Dieselwrenches

It is basically similar to e7 but yes egr system on that truck can be problematic. Not to mention the difficulty it adds to owners for doing their own repairs.

If you pull fuse with mdrive it will lock truck into one gear. Using the mud/snow switch would be your best bet.

I would start by draining oil. If you find ceramic pieces then drop oil pan and inspect cam.

The code may be set because the commanded vtg position differed from actual vtg position. Meaning actuator isn't going to the position it's supposed to. The actuator control module, actuator air drier, actuator or vtg all are in play. Make sure vtg sector moves freely by hand. May have someone with Mack software re calibrate vtg as well.

Where about is it leaking from on pan? If it's close to back it may be from not sealing seam between block and flywheel housing with rtv before installing pan.

Have a dealer pull codes using vmac 3 diagnostic software and give you copy of codes. Each code will tell you severity and which one puts into limp mode and counts.

There should always be historical code. Without actual code might as well be shooting in the dark. Have you pulled flash code when active?

The light only comes on based off sensor on rear end when sensing engaged. If sensor is bad or connector/wiring then it won't light when engaged.

Did you just get new injectors or new unit pumps as well. Unit pumps can be fairly problematic at higher mileages due to under fueling. However, you can't really test individual unit pumps. If they're original and you're experiencing low power, especially at low end, I'd say replace them first.

Did the solenoid for econo adv get changed?

Did you try tem sensor like truckster suggested, I would go there next. Doing injectors isn't a bad idea either.

Not to sound rude. But how do you know it's a low voltage on the ground? Can you be more descriptive on the exact issue you're having?

Does oil pressure drop first? If so check oil pressure sensor, just right off eecu, round connector, there will be two identical ones, oil pressure is the upper one, if connector is oily replace sensor and install anti wicking harness, if dry try switching sensor with sensor just below. They are the same part number, upper is for oil pressure, lower for crankcase pressure.

Does oil pressure drop first? If so check oil pressure sensor, just right off eecu, round connector, there will be two identical ones, oil pressure is the upper one, if connector is oily replace sensor and install anti wicking harness, if dry try switching sensor with sensor just below. They are the same part number, upper is for oil pressure, lower for crankcase pressure.

This year truck will have a computer controlled motor. Not sure about running high speeds without knowing trans and rear end specs.