Grand Cherokee 2WD L6-4.0L VIN S (1997)
Fuel Level Sensor: Description and Operation
FUEL LEVEL SENSOR-PCM INPUT
The fuel level sensor (fuel gauge sending unit) sends a signal to the Powertrain Control Module (PCM) to indicate fuel level. The purpose of this
feature is to prevent a false setting of misfire and fuel system monitor trouble codes if the fuel level is less than approximately 15 percent, or
more than approximately 85 percent of its rated capacity It is also used to send a signal for fuel gauge operation via the CCD bus circuits.
CIRCUIT OPERATION
The fuel level sensor is a variable resistor. Circuit G4O provides the fuel level input to cavity C26 of the Powertrain Control Module (PCM). The
PCM broadcasts fuel level data on the CCD bus. The micro-processor in the instrument cluster receives the message on the CCD bus, calculates
fuel gauge needle position and adjusts the gauge.
