Ignore the P0700, it is just telling you that there is the P0841 fault.
Unfortunately, the problem isn't as easy as just diagnosing it.
I would recommend getting the AlldataDIY subscription for your truck.
It will give you the fault code diagnostics, with diagrams.
But a scanner will be needed that will access the transmission parameters.
You might call a local shop and see if they can diagnose the problem.
Sorry, but there isn't a lot of options, unless you can get the truck to Anchorage.
P0700-TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
Ignition on and battery voltage greater than 10 volts .
An active DTC is stored in the TCM. One Trip Fault. Three good trips to turn off the MIL.
DTC present in the transmission control module
P0841-LR PRESSURE SWITCH RATIONALITY
LOSS OF PRIME AND/OR TRANSMISSION CONTROL RELAY DTC PRESENT
LOW FLUID LEVEL
LOW LINE PRESSURE
REVERSE CARRIER SNAP RING DISLODGED
CRACKED OR MIS-INSTALLED PRIMARY OIL FILTER OR FILTER SEAL
STICKING MAIN REGULATOR VALVE IN PUMP VALVE BODY
NO. 1 CHECK BALL CUT OR DAMAGED
WIRING AND CONNECTORS
(T50) LR PRESSURE SWITCH SENSE CIRCUIT OPEN
(T50) LR PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
(T50) LR PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
TRANSMISSION SOLENOID/TRS ASSEMBLY
POWERTRAIN CONTROL MODULE