GM Service Manual Online
For 1990-2009 cars only
Figure 1:

AF Electrical Connectors


Object Number: 945787  Size: LF
(1)Fuel Gage Select Switch Connector C003
(2)Fuel Gage Select Switch/Fuel Indicator Assembly and Panel Dimmer Switch Assembly
(3)CNG Fuel Tank Vent Boot Cover
(4)6-Way In-line Tank Harness Connector C004
(5)1-Way Inline HPL Power Circuit Connector C005
(6)3-Way CNG Fuel Tank Pressure (FTP) Sensor Connector
(7)2-Way High Pressure Lock-off (HPL) Solenoid Valve Connector -- Black
(8)2-Way CNG Fuel Tank Temperature (FTT) Sensor Connector -- Gray
(9)High Pressure Lock-off (HPL) Solenoid Valve
(10)CNG Fuel Tank Pressure (FTP) Sensor
(11)Alternative Fuel System Ground G112
(12)Low Pressure Regulator (LPR)/Low Pressure Lock-off (LPL) Solenoid Valve Mounting Studs
(13)Fuel Injector Control Module (FICM) Connector
(14)AF Injector Relays 1-4
(15)2-Way Fuel Rail Temperature (FRT) Sensor Connector
(16)3-Way Fuel Rail Pressure (FRP) Sensor Connector
(17)10 Way In-line Fuel Rail Connector C001
(18)2-Way Low Pressure Lock-off (LPL) Solenoid Valve Connector
Figure 2:

AF Fuel System


Object Number: 933918  Size: LF
(1)CNG Fuel Outlet Line
(2)CNG Fuel Tank Pressure (FTP) Sensor
(3)CNG Fuel Fill Line and Check Valve
(4)High Pressure Lock-off (HPL) Manual Shut-off Fitting
(5)HPL Pressure Relief Device (PRD) Vent Line
(6)HPL Solenoid Tank Valve
(7)CNG Fill Valve Vent Boot -- shown disconnected
(8)CNG Fill Valve
(9)High Pressure Regulator (HPR) Coolant Hoses
(10)HPR Pressure Relief Device (PRD)
(11)HPR CNG Fuel Outlet Line to Filter Inlet
(12)CNG Fuel Filter Drain Plug
(13)High Pressure Regulator (HPR)
(14)CNG Underbody Fuel Line to Underhood Flex Line Fitting
(15)Low Pressure Lock-off (LPL) Solenoid Valve
(16)Low Pressure Regulator (LPR)
(17)CNG Fuel Rail Crossover Fuel Hose
(18)CNG Fuel Injectors
(19)CNG Fuel Rail
(20)CNG Fuel Rail Temperature (FRT) Sensor
(21)CNG Fuel Rail Pressure (FRP) Sensor
Figure 3:

Engine Compartment Fuse/Relay Center


Object Number: 933979  Size: MF
(1)Engine Compartment Fuse/Relay Center