Civic L4-1.7L CNG (2003)
NO - Go to step 19.
19. Turn the ignition switch OFF.
20. Remove PGM-FI main relay 2 (A).
21. Connect PGM-FI main relay 2 4P connector terminals No.1 and No.2 with a jumper wire.
22. Turn the ignition switch ON (II).
23. Measure voltage between fuel pressure regulator shut-off solenoid valve 2P connector terminal No.2 and body ground within the first 2 seconds
after the ignition switch was turned ON (II).
Is there battery voltage?
YES - Check the fuel subharness, and repair it as necessary. Replace the PGM-FI main relay 2.
NO - Repair open in the wire between PGM-FI main relay 2 and the fuel pressure regulator shutoff solenoid valve, and the fuel subharness 6P
connector.
24. Turn the ignition switch OFF.