DTC P0094 OBDII code setting means that the Powertrain Control Module (PCM) has detected a decrease in fuel pressure. The PCM is programmed to monitor fuel pressure, noting that fuel pressure varies by manufacturer. It is worth mentioning that this code is normally stored on diesel engine vehicles.
Low-pressure fuel is pumped from the tank to the high-pressure injector pump by means of a supply pump, which is connected to the rail or inside the fuel tank.
To monitor the fuel system, the PCM uses fuel pressure sensors. These are placed at strategic points in the fuel supply system. There is one sensor for each segment of the system.
If the PCM detects that the fuel system pressure does not match the programmed specifications for a set time, this code will be stored.