SEAL 3418536 - Caterpillar

Illustration 1 g01457059
Schematic of the Fuel Level SensorThis diagnostic code is associated with the fuel level sensor. The FMI 03 means that the ECM has determined that the voltage of the circuit for the sensor is above normal. Refer to Systems Operation, "Input Components" for information regarding the operation of the sensor and the location.The fuel level sensor is used to determine the level of the fuel inside the fuel tank. The sensor is mounted at the bottom of the guide tube. A float is located inside the guide tube. A metal disk is attached to the bottom of the float. The fuel level sensor emits an ultrasonic signal up the guide tube. The ultrasonic signal will be reflected off the metal disk and the signal will return to the sensor. The sensor measures the travel time of the ultrasonic signal. The output of the fuel level sensor is a 4000 Hz PWM signal that will vary with a duty cycle from 0 percent to 100 percent. The duty cycle changes as the fuel level in the tank changes. The VIMS recognizes a duty cycle in the range of 5 percent to 95 percent as a valid input from the sensor. The possible causes of this diagnostic code are listed below:
The signal circuit for the sensor is open.
The signal circuit for the sensor is shorted to the +battery circuit.
The sensor has failed.
The power circuit or the ground circuit has failed.
The ECM has failed. This is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0096 FMI 03 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:This diagnostic code causes the fuel gauge to always indicate that the fuel tank is empty. This failure may also cause the fuel gauge to intermittently indicate that the fuel tank is empty. The VIMS will not know the current fuel level. The VIMS will detect the failure and the VIMS will report the diagnostic information to the operator via the message center in the cab. A level two fault will be logged and displayed. This diagnostic code indicates a short circuit to the +battery.Test Step 1. CHECK FOR POWER AT THE SENSOR.
Do not disconnect the harness connector from