PUMP GP-FUEL INJECTION 3589085 - Caterpillar

Illustration 1 g03107559
Implement Pump Load Pressure SensorThis code is associated with the Implement Pump Load Pressure Sensor. 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 sensor is located on the left side of the Implement Control Valve.The Implement Pump Load Pressure Sensor receives power from the 8V power supply of the Implement ECM. The sensor is connected to ground from the 8V sensor return for the Implement ECM. The illustration above indicates the power and ground connections for the pressure sensor.The sensor is a 50 MPa (7252 psi) rated pressure sensor that operates at approximately 500 Hz. The pressure sensor sends a PWM input signal to the ECM. The duty cycle of the signal will vary from 5% to 95%.If the PWM duty cycle or voltage of a sensor input circuit is greater than 97%, an FMI 03 diagnostic code will be activated.The following table indicates the sensor PWM duty cycles at the given oil pressures.
Table 1
Implement Pump Load Pressure Sensor PWM Duty Cycle versus Pressure    
Pressure     Duty Cycle (Percent)     Pressure     Duty Cycle (Percent)    
0 mpa (0 psi)     5     25.6 mpa (4000 psi)     51    
13.8 mpa (2000 psi)     30     31.0 mpa (4500 psi)     61    
17.2 mpa (2500 psi)     36     34.5 mpa (5000 psi)     67    
20.7 mpa (3000 psi)     42     37.9 mpa (5500 psi)     73    
24.1 mpa (3500 psi)     48     50 mpa (7252 psi)     95     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 the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Inspect the connections for the following:
Connections are clean.
Connections are secure.
Connections are in good condition.Note: If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Test Step 1. CHECK THE DUTY CYCLE AND THE SIGNAL FREQUENCY AT THE SENSOR
Turn the key start