Fuel Shut-off Solenoid: Description and Operation

Fig.37 Fuel Pressure Regulator Mounting:

Fig.38 Fuel Pressure Regulator Components:

HIGH PRESSURE FUEL SHUTOFF SOLENOID - CNG ONLY
The high-pressure fuel shut-off solenoid is an integral part of the fuel pressure regulator (Fig. 37) or (Fig. 38).

The high-pressure fuel shut-off solenoid is used as an on/off valve to electrically control high-pressure gas flowing through the fuel pressure regulator. It is operated by the Powertrain Control Module (PCM). This is accomplished through the high-pressure fuel shut-off solenoid relay. Also refer to High-Pressure Fuel Shut-Off Solenoid Relay.

Fig.48 Low-Pressure Fuel Shut-Off Solenoid Location:

LOW PRESSURE FUEL SHUTOFF SOLENOID - CNG ONLY
The low-pressure fuel shut-off solenoid is mounted to the left side of (inlet side of) the fuel injector rail (Fig. 48).

The low-pressure fuel shut-off solenoid is controlled by the Powertrain Control Module (PCM) through a 12 volt + output from the Automatic Shut-Down (ASD) relay. After high cylinder pressure has been lowered by the fuel pressure regulator, this solenoid is used as an ON/OFF valve to electrically control natural gas entering the fuel rail assembly. When the ignition switch is in the OFF position, fuel supply is shut off to the engine. Refer to ASD relay for additional information.