My truck gave me the p1211 code today. I'm Trying to use dash command to get more info. What should I be monitoring and how do I do it? I'm not familiar with these apps at all?

 

Same here. You should look at a thread I started earlier today. Could be a lot of things. Hopefully more will chime in.

 

ICP (Injector Control Pressure), don't know if dash command can do that or not.
You should monitor pressure and check for leaks in your High Pressure Oil system.

 

Dash Command can do ICP, but I am unsure about IPR.

RPM (0-3500)
Fuel Injector Pulse Width - FIPW (0-6 milliseconds or 0-6000 microseconds)
Injector Pressure Regulator - IPR (0-100%)
Injector Control Pressure - ICP (0-3500 PSI)

Turn on your logging so you can share the readings. If you want a full read on the truck, include these:

MPH (0-100)
Manifold Absolute Pressure - MAP (0-50 PSI)
Exhaust Back Pressure - EBP (0-55 PSI)
Engine Oil Temperature - EOT (0-250 Degrees F)
Torque Converter Slip - Slip (0-1000 RPM)

To do a sensor test, use MAP, EBP, and Barometric Pressure - BARO (0-20 PSI). With those three programmed in, turn the key on, but don't start the motor. They should all read the same PSI. If you get a mix of volts and PSI, please log them and share.