2.2L - Cavalier - CNG
NOTE:
Replace all "O" rings that are disconnected or loosened.
- Connect scan tool to Data Link Connector (DLC). Clear all existing DTC's. Start engine and verify engine is operating on CNG. Using scan tool, select High Pressure Lock-Off (HPL) output control. See Fig 1. Close HPL and observe the Fuel Pressure Sensor parameter on scan tool. If Fuel Pressure Sensor parameter fails to decrease, go to next step. When engine stalls, turn ignition off. Remove CNG 20-amp fuse. Slowly open fuel line fittings in order to release remaining pressure.
- Remove fuel tank cover dust plug. Close manual lock-down screw located on HPL manual shutoff fitting by rotating the Allen screw clockwise until fully seated. Turn ignition off. Disconnect negative battery cable. Loosen fuel line fitting at Low Pressure Lock-Off (LPL) inlet port several turns. Do not remove fitting. If fuel is not venting with LPL inlet fitting loosened, relieve fuel line tension by pulling line away from LPL.
- Loosen fuel line fitting at HPL inlet port several turns. Do not remove fitting. Relieve fuel line tension by pulling line away from HPL. Pressure is released when fuel line can be pulled away from HPL inlet port.