2014 Volvo VN. Updated Trans ECU. Installed new clutch. I cannot calibrate the clutch because either the transmission or the laptop cannot see engine RPMs. The tach in the dash works though. I'm banging my head in the wall here. I cannot revert back to the old transmission programming because our tech tool apparently does not have access on the back end. Help? All of my j1939 lines have checked out. Does anyone know the exact routing of the engine speed signal?
This is going to sound crazy. Humor me. Do you have good battery voltage? Did you install driveshaft?
