P2844 indicates an intermittent electrical signal from the shift fork D position sensor or its circuit. The transmission control module detects a sporadic loss of communication or erratic voltage from the sensor that monitors the position of shift fork D, which controls gear engagement for a specific gear set.
The sensor itself may have internal wear, contamination, or electrical failure causing an intermittent signal.
Frayed wires, corrosion, loose terminals, or damaged connectors in the sensor circuit can create intermittent contact.
Physical wear, debris, or lack of lubrication on the shift fork or its rails can cause erratic sensor readings as the fork moves inconsistently.
Internal TCM driver or signal processing circuitry for the shift fork D position input may be degrading.
Rare; a fault in the powertrain control module's communication with the TCM could mimic an intermittent sensor signal.
Driving is not recommended. The transmission may enter limp mode, leave you unable to select certain gears, or cause further mechanical damage if the shift fork is binding.
On many designs the sensor is external and replaceable without removing the transmission, but some integrate it into the mechatronic unit or valve body requiring more extensive disassembly.
Almost never. The PCM is the least likely cause; the fault is almost always the sensor, its wiring, or the mechanical shift fork assembly. Replace the PCM only after all other causes are conclusively ruled out.
Indirectly. Low or contaminated fluid can cause shift fork binding or erratic actuation, which may produce an intermittent position signal, but the code itself points to an electrical circuit issue.