KIT (CARTRIDGE) 4J8491 - Caterpillar

Illustration 1 g00797108
Schematic of the Solenoid Valve for the Number Two Check Valve This diagnostic code is associated with the solenoid valve for the number two check valve. This diagnostic code is recorded when the implement ECM reads the voltage of the solenoid circuit as being above normal. The signal circuit of the solenoid may be shorted to the +battery circuit.The possible causes of this diagnostic code are listed:
The solenoid energizer circuit is shorted to the +battery circuit.
The implement ECM has failed. This is unlikely. System Response:When this diagnostic code occurs, there is no warning on the monitor. The diagnostic code will be active when the control for the work tool is actuated. The diagnostic code will be active when the control for the work tool is not actuated. The diagnostic code will cause the solenoid to be energized at all times. Test Step 1. CHECK THE SOLENOID CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the solenoid.
Disconnect the two machine harness connectors from the implement ECM.
At the machine harness connector, measure the resistance from the signal contact CONN190-3 (wire K875-BU) of the machine harness to all possible sources of +battery circuit. Measure the resistance to all contacts that are used in the CONN189 and CONN190 harness connectors.Expected Result:Each resistance measurement should be greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to test step 2.
NOT OK - One or more resistance measurements is not correct. There is a short in the machine harness. The short is between signal contact CONN190-3 (wire K875-BU) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts of the harness connectors and clean the contacts.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Enter the service mode of the operator monitor and clear all of the inactive diagnostic codes.
Operate the machine.
Determine if CID 1523 FMI 03 is present. Check the "ACTIVE ERROR" screen on the monitor.Expected Result:The diagnostic code for the solenoid is NOT present.Results:
YES - The diagnostic code is NOT present. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.STOP
NO - The diagnostic code has not been corrected. It is unlikely that the implement ECM has failed.Repair: Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the implement ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for the Tool Control System.STOP