PUMP GP-ENGINE OIL 7C8538 - Caterpillar

The solenoid is used to shutoff, release, distribute, or combine fluids on the machine. Generally, multiple solenoids are located together on a manifold. The solenoid converts electrical energy into magnetic energy, moving a spool located inside the housing of the valve. A spring is used to hold the spool in position until the solenoid is energized.The magnetic force that acts on the valve spool is created when a coil inside the solenoid is energized.Possible Causes for an FMI 3 Diagnostic code are:
The harness is shorted.
The Machine ECM has failed. A failure of the ECM is unlikely.Possible causes for an FMI 5 Diagnostic code are:
There is an open in the circuit.
The solenoid has failed.
The Machine ECM has failed. A failure of the ECM is unlikely.Possible causes for an FMI 6 Diagnostic code are:
A wire is shorted to ground.
The solenoid has failed.
The Machine ECM has failed. A failure of the ECM is unlikely.
Illustration 1 g03706520
Illustration of Machine ECM solenoid connections
Note: The diagrams above are simplified schematics of the Machine ECM and the Switch Panel connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the machine Electrical Schematic.Diagnostic Trouble Code Procedure
Note: Prior to starting this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. Check the wiring harness for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure.
Table 2
Troubleshooting Test Steps Values Results
1. Identify Active FMI Code Associated With Solenoid Circuit
Code present. FMI 3 diagnostic code, proceed to Test Step 2.
FMI 5 diagnostic code, proceed to Test Step 3.
FMI 6 diagnostic code, proceed to Test Step 5.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Machine Harness For A Short
A. Turn the key start switch and the disconnect switch OFF.
B. Disconnect the harness connection at the solenoid.
C. If the solenoid is connected to ECM, disconnect the connector from ECM.
D. Measure the resistance of the solenoid signal contact to all connectors at the Machine ECM.
Each reading is greater than 5K Ω. OK - All resistance readings are greater than 5K Ω .
Proceed to Test Step 7.
NOT OK - One or more readings are less than 5 Ω.
Repair: A short exists between the signal contact and the circuit with the low resistance. Repair or replace the machine harness.
Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose connection or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit.
STOP
Begin Process For FMI 5 Troubleshooting HERE
3. Check The Solenoid
A. Turn the key start switch and the disconnect switch OFF.
B. Disconnect the solenoid from the machine harness.
C. Place a jumper