ELECTRONICS GP-POWER TRAIN 3373364 - Caterpillar

Illustration 1 g01228124
Main pump pressure sensor connectionsThis diagnostic code is associated with the main pump pressure sensor. This sensor is installed on machines that have the electronic hydraulic implement control system.This diagnostic code is recorded when the ECM reads the signal from the sensor as being below normal.The possible causes of the diagnostic code is listed:
The signal is shorted to ground.
A sensor has failed.
The ECM has failed. This is unlikely.System Response:The ECM will use the data from this sensor when the calibration procedures for the implement solenoids are performed. When the ECM activates diagnostic code for the sensor, the implement solenoid calibration procedures will not be successful.Note: Ensure that there are no active CID 0262 diagnostic codes for the 5 volt sensor power supply before performing this procedure. Ensure that CID 1450 FMI 04 is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the problem has been corrected, clear the created diagnostic codes.Test Step 1. CHECK THE SENSOR
Turn the disconnect switch and the key start switch to the ON position.
Observe the status of the diagnostic code. Then, disconnect the sensor from the machine harness.Expected Result:If the sensor is faulty, the CID 1450 FMI 04 diagnostic code will become inactive and a CID 1450 FMI 03 diagnostic code will become active when the sensor is unplugged. The sensor is the cause of the diagnostic code if the CID 1450 FMI 04 diagnostic code is NO longer active.Results:
OK - The CID 1450 FMI 04 diagnostic code remains active. The sensor is not faulty. The machine harness may have failed. Proceed to Test Step 2.
NOT OK - The CID 1450 FMI 04 diagnostic code is NO longer active. A CID 1450 FMI 03 diagnostic code is now active. The machine harness and the ECM are operating properly. Repair: The sensor has failed. Replace the sensor. Verify that the new sensor corrected the problem.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
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 ECM.
At the J1 machine harness connector, measure the resistance from contact J1-36 (wire M919-BU) to frame ground. Measure the resistance from contact J1-36 (wire M919-BU) to all of the other contacts that are used in the ECM connectors.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The signal circuit is correct. Proceed to Test Step 3.
NOT OK - The resistance measurement is less than 5000 ohms.Repair: The machine harness has failed. There is a short in the machine harness between the sensor signal circuit and frame ground. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
Inspect the harness connectors and clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery