Sierra 3500 4WD V8-6.6L DSL Turbo VIN 2 (2004)
Fuel Gauge Sender: Description and Operation
FUEL LEVEL SENSOR
The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level
sensor contains a variable resistor which changes resistance in correspondence with the amount of fuel in the fuel tank. The engine control module
(ECM) sends the fuel level information via the class 2 circuit to the instrument panel cluster (IPC). This information is used for the instrument panel (I/P)
fuel gage and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.