FUEL QUANTITY SOLENOID
DESCRIPTION
The fuel quantity solenoid is located in the back of the
high pressure pump. The solenoid is pulse width mod-
ulated by the ECM and meters the amount of fuel that
flows into the high pressure elements inside of the
high pressure pump. The solenoid is also inactive dur-
ing the first 30 seconds to allow maximum fuel pres-
sure to the fuel rail during start up.
OPERATION
The fuel quantity solenoid is a pulse width modulated valve that controls the amount of fuel sent or delayed to the
high pressure pump elements inside of the high pressure pump. The ECM determines the fuel pressure set point
based on engine sensor inputs. If the actual fuel rail pressure is too low, the ECM commands the solenoid to allow
more fuel to flow to the high pressure pump. This minimizes the difference between the actual fuel rail pressure
reading and the set point. The ECM will also operate the solenoid, delaying fuel if the fuel rail pressure becomes to
high.
The fuel quantity solenoid is commanded open by the ECM to allow the high pressure pump to build maximum
pressure (1600 BAR, 23,200 PSI) (Refer to 14 - FUEL SYSTEM - WARNING). the solenoid also has fuel tank heat
protection function that meters the exact amount of fuel to prevent excess heated fuel from returning to the fuel tank
REMOVAL
1. Disconnect the negative battery cable
2. Remove the charge air inlet hose.
3. Disconnect the fuel quantity solenoid wiring har-
ness connector.
4. Remove the solenoid from the back of the high
pressure pump.
NOTE: Inspect the fuel quantity solenoid and high
pressure pump passage for contamination or cor-
rosion. If contamination or corrosion is present
replace the high pressure pump.
5. Inspect solenoid and pump for corrosion.
14 - 64
FUEL DELIVERY - 2.8L DIESEL
KJ