MUFFLER & CONVERTER AS 2304123 - Caterpillar

Solenoids are used to shutoff, release, distribute, or mix fluids on the machine. Generally, multiple solenoids are located together on a manifold. The solenoid converts electrical energy into magnetic force, 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.Possible causes for an FMI 4 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:
The return circuit for the solenoid is shorted to a ground source.
The Machine ECM has failed. A failure of the ECM is unlikely.
Illustration 1 g06123016
Diagram of the solenoid connections associated with the Cat Grade Control ECM.
The preceding diagram is a simplified schematic of ECM connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic to view the entire circuitry of the machine.Diagnostic Trouble Code Procedure
Prior to beginning this procedure, inspect the harness connectors 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.
Identify the active FMI code associated with the components.
Determine the active failure mode code and use the list below to determine which procedure to follow.
FMI 4 diagnostic code, proceed to Table 2
FMI 6 diagnostic code, proceed to Table 3
Table 2
FMI 4 Troubleshooting
Troubleshooting Test Steps Values Results
1. Check The Machine Harness For An Open
A. Turn the key start switch and the disconnect switch to the OFF position.
B. Disconnect the solenoid from the machine harness.
C. Disconnect the harness connection at the ECM.
D. Connect a jumper wire at the two contacts at the solenoid end of the wiring harness.
E. At the ECM side of the machine harness, measure the resistance from the signal to the return contact.
Each reading is less than 5 Ω.
OK - The reading is less than 5 Ω, the harness is correct.
Proceed to Test Step 2.
NOT OK - The reading is greater than 5K Ω. A circuit is open in the machine harness.
Repair : The open is in the wire for the solenoid signal or the return wire for the solenoid. Repair or replace the machine harness.
Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit.
STOP
2. Check If The Diagnostic Code Remains
A. Turn the key start switch and the disconnect switch to the ON position.
B. Clear all diagnostic codes.
C. Operate the machine.
D. Stop the machine and engage the safety lock lever.
E. Check if diagnostic