ALTERNATOR GP- 2834679 - Caterpillar

Illustration 1 g00610608
Schematic of the Hammer Speed circuitThis diagnostic code is associated with the hammer speed 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 energizer circuit is shorted to +battery.
The machine ECM has failed. This is unlikely. When this failure occurs, a warning is shown on the message center and the machine ECM disables the circuit. Test Step 1. CHECK THE SOLENOID ENERGIZER CIRCUIT FOR A SHORT TO +BATTERY.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors from the machine ECM.
Disconnect the suspect solenoid from the machine harness.
At the machine harness connector J2, measure the resistance from the solenoid energizer circuit J2-21 (wire P953-WH) to all the possible sources of +battery.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Resistance measurements are greater than 5000 ohms. The harness is correct. Proceed to test step 2.
NOT OK - The resistance is less than 5000 ohms. There is a short to +battery in the solenoid energizer circuit of the harness.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 2. 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.
Check if the diagnostic code is displayed on the message center. The diagnostic information may also be viewed with the ET.Expected Result:The diagnostic code for the solenoid is not present on the message center. Results:
YES - The diagnostic code is not present. The diagnostic code does not exist at this time. The initial failure 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 is present. The failure has not been corrected. The machine ECM has failed. It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again.Repair: If the cause of the failure is not found, replace the machine ECM. See Testing And Adjusting, "Electronic Control Module (ECM) - Replace". Stop.