TANK 2874788 - Caterpillar

Illustration 1 g00610532
Schematic of the System Pressure UP- Reverse circuitThis diagnostic code is associated with the system pressure up- reverse valve. The FMI 03 means that the machine ECM determined that the voltage is above normal. The possible causes of this failure are listed below:
The solenoid has failed.
The solenoid energizer circuit is shorted to +battery.
The main backup switch has failed.
The machine ECM has failed. This is unlikely.When this diagnostic code occurs, a warning is displayed on the message center. The machine ECM disables the solenoid and the machine hydraulics system. Test Step 1. CHECK THE SOLENOID ENERGIZER CIRCUIT FOR A SHORT TO +BATTERY.
Turn the key start switch to the OFF position.
Disconnect the solenoid from the machine harness.
Disconnect the machine harness connectors J1 and J2 from the machine ECM.
At the machine harness for the solenoid, measure the voltage between the contact 1 (wire P950-YL) of the machine connector for the solenoid to frame ground.Expected Result:The voltage is approximately 0.0 0.5 DCV.Results:
OK - The voltage is approximately 0.0 0.5 DCV. The voltage is correct. Proceed to test step 2.
NOT OK - The voltage is greater than 0.0 0.5 DCV. The voltage is not correct. The solenoid energizer circuit is shorted to +battery.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 2. CHECK THE RETURN CIRCUIT OF THE SOLENOID FOR A SHORT TO +BATTERY.
The key start switch remains in the OFF position.
The solenoid remains disconnected from the machine harness.
The machine harness connectors J1 and J2 remain disconnected from the machine ECM.
At the machine harness for the solenoid, measure the voltage between the contact 2 (wire H807-YL) of the machine connector for the solenoid to frame ground.Expected Result:The voltage is approximately 0.0 0.5 DCV.Results:
OK - The voltage is approximately 0.0 0.5 DCV. The voltage is correct. Proceed to test step 4.
NOT OK - The voltage is greater than 0.0 0.5 DCV. The voltage is not correct. Proceed to test step 3.Test Step 3. CHECK THE MAIN BACKUP SWITCH.
Turn the key start switch to the ON position.
Ensure that the main backup switch is in the AUTO position.
The solenoid remains disconnected from the machine harness.
The machine harness connectors J1 and J2 remain disconnected from the machine ECM.
Disconnect wire H807-YL from contact 11 of the main backup switch.
At the main backup switch, measure the voltage between contact 11 and frame ground. Expected Result:The voltage is approximately 0.0 0.5 DCV.Results:
OK - The voltage is approximately 0.0 0.5 DCV. The voltage is correct. Proceed to test step 4.
NOT OK - The voltage is greater than 0.0 0.5 DCV. The voltage is not correct. The main backup switch has failed.Repair: Replace the main backup switch. Stop.Test Step 4. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts of the harness connectors and clean the contacts.
Reconnect all machine harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Acknowledge any active events that are displayed on the message center by pressing the "OK" key.
Operate the machine.
Verify