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

AF Electrical Connectors


Object Number: 506026  Size: LF
(1)23-Way In-line Connector C200 Black
(2)10-Way In-line Connector C251 Natural
(3)Passthrough P001, not shown
(4)Data Link Connector (DLC)
(5)10-Way In-line Connector C250 Natural
(6)Fuel Gage Selector Switch/Fuel Indicator Lamp and Panel Dimmer Switch Assembly
(7)Fuel Gage Select Switch Connector C254
(8)Passthrough P401
(9)6-Way In-line Connector C450 Black
(10)1-Way In-line Connector C454
(11)Fuel Tank Pressure Sensor Connector C452 Black
(12)High Pressure Lock-off Connector C453 Black
(13)Fuel Tank Temperature (FTT) Sensor Connector C451 Gray
(14)High Pressure Lock-off (HPL) with Internal Fuel Tank Temperature Sensor
(15)Fuel Tank Pressure (FTP) Sensor
(16)G112
(17)Fuel Gage Relay Connector C012
(18)Lock-off Relay Connector C011
(19)AF Fuel Pump Relay Connector C007
(20)Ignition Relay Connector C004
(21)AF Engine Control Module
(22)AF Engine Control Module Connector C001 Blue
(23)AF Engine Control Module Connector C002 White/Clear
(24)10-Way In-line Connector C018 Black
(25)10-Way In-line Connector C017 Gray
(26)6-Way In-line Connector C019 Black
(27)GMS/MCV Assembly
(28)Mixture Control Valve Connector C021
(29)Gas Mass Sensor Connector C010
(30)Low Pressure Lock-off Connector C014
Figure 2:

AF Fuel System


Object Number: 506031  Size: LF
(1)CNG Fuel Outlet Line
(2)Fuel Tank Pressure (FTP) Sensor
(3)CNG Fill Line
(4)High Pressure Lock-off Manual Shut-off Fitting
(5)High Pressure Lock-off Pressure Relief Device (PRD) Line
(6)High Pressure Lock-off Solenoid
(7)CNG Fill Line Vent Boot -- shown disconnected
(8)CNG Fill Valve
(9)High Pressure Regulator (HPR) Coolant Hose
(10)High Pressure Regulator (HPR) Pressure Relief Device (PRD)
(11)High Pressure Regulator Fuel Outlet Line
(12)High Pressure Regulator (HPR)
(13)CNG Fuel Pressure Test Port
(14)Low Pressure Regulator (LPR)
(15)Gas Mass Sensor/Mixture Control Valve Assembly (GMS/MCV)
(16)Mixture Control Valve (MCV)
(17)Gas Mass Sensor (GMS)
(18)Low Pressure Regulator (LPR) Low Pressure Hose
(19)Low Pressure Lock-off (LPL) Solenoid Fuel Inlet Line
(20)Low Pressure Lock-off (LPL) Solenoid
Figure 3:

Engine Compartment Fuse/Relay Center


Object Number: 787054  Size: MF
(1)Engine Compartment Fuse/Relay Center