Instrument Cluster

NATURAL GAS VEHICLES
Prior to attempting any diagnosis or repair procedures, read and become familiar with the Service Precations. Service Precautions

NOTE: All standard production components and Systems receive routine service under base warranty procedures.

The natural gas fuel indication system consists of the following components:
^ the Natural Gas Vehicle (NGV) module
^ the fuel gauge located in the instrument cluster
^ the fuel tank pressure sensor
^ the tank temperature sensor
^ the necessary circuitry

NGV Module
NGV module assembly:
^ consists of a 60-pin module, a bracket, a marine cover and four marine cover retainers.
^ houses the unique electronics required for natural gas fuel systems.
^ is located on the LH inner fender well, behind the coolant recovery bottle.

The NGV module assembly performs the following functions:
^ Injector drivers: the NGV module accepts eight unmodified injector signals from the powertrain control module (PCM) and allows a peak-and-sustain current to flow through the injector solenoids.

NOTE: No injector calculations are performed; the injector driver output is not determined by the NGV module.

^ Fuel gauge driver: the NGV module uses tank temperature and fuel tank pressure inputs to calculate the density of the fuel; a look-up table is used to determine the output signal to the fuel gauge.

Fuel Tank Pressure Sensor
The fuel tank pressure sensor:
^ contains integral solid state circuitry that outputs a voltage signal that is proportional to pressure.
^ has an output that is linear from 344.74 kpa (50 psi) up to 27,579.03 kPa (4000 psi).
^ is mounted in the midship fuel tank solenoid valve.

Tank Temperature Sensor
The tank temperature sensor:
^ changes resistance in response to the temperature of the fuel in the fuel tank; as the surrounding temperature increases, the resistance decreases (the voltage signal also decreases).
^ provides a signal to the NGV module that indicates the temperature of the fuel.
^ is mounted in the high-pressure fuel line downstream of the coalescer filter.

Instrument Cluster Replacement
When an instrument cluster replacement is necessary, contact the Cluster Order System at 1-800-259-9700 (U.S.) or 1-800-663-9974 (Canada).