System Description
WARNING: This page is about a different car, the 2012 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.
Low fuel pressure control
- The low fuel pressure pump is controlled by the fuel pump control module (FPCM) and pumps fuel according to a driving condition. The pumped fuel passes through the fuel filter and is sent to the high pressure fuel pump. FPCM controls the low pressure fuel pump, according to a signal from ECM as shown in the table below.
Conditions Amount of fuel flow Supplied voltage After a laps of 1 second after ignition ON OFF 0 V - For 1 second after turning ignition switch ON
- Engine is running under low load and low speed conditions
Low Approximately 8.5 V - Engine cranking
- Engine coolant temperature is below 10°C (50°F)
- Engine is running under high load and high speed conditions
High Battery voltage (11 - 14 V) Except the above Mid Approximately 10 V - Low fuel pressure is adjusted by the fuel pressure regulator.
High fuel pressure control
- The high pressure fuel pump raises the pressure of the fuel sent from the low pressure fuel pump. Actuated by the camshaft, the high pressure fuel pump activates the high pressure fuel pump solenoid based on a signal received from ECM, and adjusts the amount of discharge by changing the timing of closing the inlet check valve to control fuel rail pressure.