Diesel Data: Automotive Repair

Fuel Gauge: Description and Operation



FUEL GAGE

The IPC displays the fuel level as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the fuel level percent. The fuel gage defaults to empty if:
- The PCM detects a malfunction in the fuel level sensor circuit.
- The IPC detects a loss of class 2 communications with the PCM.

When the fuel level is less than a pre-determined value, the low fuel indicator illuminates.

Reviewing the fuel system description will further explain how the system functions. Refer to Fuel System Description in Computers and Control Systems - 6.0L (LQ4).