Low Pressure Lock-Off (LPL) Solenoid

The LPL is a normally closed, solenoid valve. The LPL is mounted in the Intermediate pressure line. The AF ECU controls LPL solenoid operation. The AF ECU energizes the LPL solenoid only when engine cranking or running is detected. Anytime the engine is stopped the AF ECU de-energizes the LPL solenoid which stops fuel flow. The AF ECU operates the LPL and the High Pressure Lock-off (HPL) solenoid at the same time except at ignition ON. During ignition ON the HPL is opened while the LPL remains closed in order to charge the fuel system with CNG. The LPL is supplied fuel from the HPR with fuel pressure between 115-220 psi (793-1517 kpa). The outlet of the LPL supplies the Low Pressure Regulator (LPR) with fuel.