Natural Gas Vehicle Module

The Natural Gas Vehicle (NGV) Module
^ Houses the unique electronics required for natural gas systems.
^ Is located in a waterproof housing (engine control housing cover and bracket) in front of A/C condenser behind radiator grille.

NGV Module has the following functions:
1. Injector drivers: Accepts eight unmodified injector signals from the Powertrain Control Module (PCM) and allows a peak-and-sustain current to flow through the injectors, solenoids. No calculations are performed; the injector driver output is not determined by the fuel indication module.
2. Fuel gauge driver: Uses fuel temperature and fuel pressure inputs to calculate density of fuel and a lookup table to determine the output to the low fuel warning switch (through a combination of discreet resistors), which drives the fuel gauge located in the instrument cluster.
3. Power and ground supply:
Supplies power to instrument cluster components on Circuit 231 (BK/Y) when ignition switch is in RUN and START position. Ground for fuel gauge, low fuel level warning switch and voltmeter is supplied on Circuit 570 (BK/W). Circuit 231 (BK/Y) supplies power to the following components.

Instrument cluster connector C251:
^ Fuel gauge
^ Voltmeter
^ Low fuel level warning switch
^ Low fuel lamp
^ Malfunction indicator lamp
^ Speedometer

Instrument cluster connector C250:
^ Temperature gauge
^ Oil pressure gauge
^ ABS warning indicator
^ OD OFF indicator
^ Brake warning indicator
^ Air bag warning indicator