BONNET 9Y1205 - Caterpillar

Illustration 1 g02712166
Schematic of the Implement Pilot Supply Pressure Sensor
This diagnostic code is recorded when the ECM reads the input signal from the Implement Pilot Supply Pressure Sensor and the PWM duty cycle is below normal.The sensor is a PWM sensor that operates at a frequency of approximately 500Hz 100Hz. The sensor sends a PWM input signal to the ECM. The duty cycle of the signal will vary from 2% to 98%.The possible causes of this diagnostic code are listed:
The signal circuit is shorted to ground.
The sensor has failed.
The ECM has failed. This condition is unlikely.System Response:
The events related to this sensor's signal will not work properly.Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.Note: The following procedure can create numerous related diagnostic codes. Reconnect all harnesses. Then, the related diagnostic codes will be shown as being NOT active. Complete the following procedure. Then, clear all of the related diagnostic codes.Test Step 1. CHECK THE SENSOR
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from the sensor. Observe the status of the active CID 0434 FMI 04 diagnostic code.Expected Result:The status of the CID 0434 FMI 04 diagnostic code did not change when the sensor was disconnected. A CID 0434 FMI 03 diagnostic code has not been activated by the ECM. The CID 0434 FMI 04 diagnostic code remains active when the sensor is disconnected.Results:
OK - The CID 0434 FMI 04 diagnostic code remains active when the sensor is disconnected. The sensor is not the cause of the problem. Proceed to Test Step 2.
NOT OK - The CID 0434 FMI 04 diagnostic code is no longer active when the sensor is disconnected. A CID 0434 FMI 03 diagnostic code is activated by the ECM when the sensor is disconnected. The machine harness and the ECM are operating correctly.Repair: The operation of the sensor is the cause of the problem. Replace the sensor. After replacement of the sensor, verify that the operation is correct before operating the machine.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
The connector for the sensor remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 and J2 machine harness connectors from the Implement ECM.
At machine harness connector J2 for the ECM, measure the resistance between contact J2-40 wire C460-BU(Blue)and frame ground and measure the resistance to each of the other J1 and J2 circuits that are used for the Implement ECM.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.
NOT OK - One or more of the resistance measurements is not correct. The machine harness has failed.Repair: There is a short in the machine harness. The short is between the signal circuit and the frame ground. The short could also be between the signal circuit and the circuit