ALTERNATOR GP-CHARGING 2090750 - Caterpillar

Illustration 1 g02774201
Schematic of the Main Hydraulic Pump Oil Pressure Sensor
This diagnostic code is associated with the Main Hydraulic Pump Oil Pressure Sensor. The sensor produces a PWM signal. The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range.The Main Hydraulic Pump Discharge Pressure Sensor receives power from the 8V power supply of the Machine ECM. The sensor is connected to ground from the 8V sensor return of the Machine ECM. The illustration above indicates the power and ground connections for the position sensor.The Main Hydraulic Pump Discharge Pressure Sensor provides a PWM output signal in the range of 5% to 95% to the Machine ECM. The duty cycle of the PWM signal corresponds to the monitored pump pressure.If the ECM detects the frequency is less than 400 Hz or greater than 600 Hz, an FMI 08 code will be activated. The possible causes of this diagnostic code are listed below:
The sensor has failed.
Intermittent connections or poor connections
The ECM has failed. This condition is unlikely.Note: If a CID 0041 diagnostic code for the 8V power supply has been activated, correct the problem before proceeding with this procedure.Note: Before performing this procedure, inspect