PANEL-HEATER 1268332 - Caterpillar

Illustration 1 g01255117
Connections of the Main Hydraulic Pump Discharge Pressure Sensor
This diagnostic code is associated with the main hydraulic pump discharge pressure sensor. The FMI 03 diagnostic code means that the ECM has determined that the voltage of the sensor signal circuit is above normal. The pressure sensor sends a variable voltage input to the ECM that will indicate the main hydraulic pump discharge pressure. The output voltage of the sensor will be around 0.5VDC, when no pressure is applied. The output voltage of the pressure sensor will be around 4.5VDC at 34500 kPa (5004 psi) of pressure.The possible causes of this diagnostic code are listed below:
The sensor has failed.
The signal circuit for the sensor is shorted to another voltage source.
An open circuit connection to the power, the ground, or the signal wires.
The ECM has failed. This is unlikely.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. Verify that all connections in the circuit are clean, that all connections are secure and that all connections are in good condition. 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 original diagnostic code has been corrected.Test Step 1. CHECK THE POWER SUPPLY AT THE SENSOR
Turn the disconnect switch and the key start switch to the OFF position.
Do not disconnect the machine harness connector from the sensor.
At the back of the machine harness connector for the main hydraulic pump discharge pressure sensor, insert 7X-1710 Multimeter Probes along contact A (wire 997-OR(Orange)) (supply) and along contact B (wire 998-BR(Brown)) (return).
Turn the disconnect switch and the key start switch to the ON position.
Measure the voltage from contact A to contact B. Expected Result:The voltage measurement is 5.0 0.5VDC.Results:
OK. - The voltage measurement is 5.0 0.5VDC. The voltage is correct. Proceed to Test Step 2.
NOT OK. - The voltage measurement is less than 5.0 0.5VDC. The power supply voltage is not correct.Repair: There is a problem with the power supply for the sensor. Refer to the CID 0262 diagnostic code procedures in this manual for information on troubleshooting the 5V power supply circuit of the ECM. Repair the power supply circuit. After the power supply circuit is repaired, check the status of this diagnostic code. Operate the machine in order to confirm the repair.STOPTest Step 2. CHECK THE OPERATION OF THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At the machine harness connector of the Implement ECM J1, use a 151-6320 Removal Tool to remove the signal wire N931-GY(Grey) and the socket at contact J1-36 from the J1 connector. The machine harness connector J1 remains connected to the Implement ECM.
Turn the disconnect switch and the key start switch to