Express 1500 RWD V8-5.3L VIN T (2004)
Fuel Gauge: Description and Operation
FUEL GAGE
The IPC displays the fuel level on the analog fuel gage as determined by the PCM. The PCM monitors the signal circuit of the fuel level sensor. When
the fuel level sensor resistance is high, the fuel gage indicates full. When the fuel level sensor resistance is low, the fuel gage indicates empty. The IPC
receives a class 2 message from the PCM indicating the filtered fuel level percent. The PCM uses 2 filters for the fuel level percent. The slow filter is
used during normal operation. The fast filter is used when the engine is just started or when the vehicle is in Park or Neutral. The fast filter allows the
fuel gage to reach the current fuel level quickly. The fuel gage defaults to empty when the following conditions occur:
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The PCM detects a malfunction in the fuel level sensor circuit. Refer to Diagnostic System Check - Instrument Cluster.
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The IPC detects a loss of class 2 communications with the PCM.
Reviewing the fuel system description will further explain how the system functions. Refer to:
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Fuel System Description in Computers and Control Systems - 4.3L
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Fuel System Description in Computers and Control Systems - 4.8L, 5.3L, and 6.0L.
