CYLINDER AS 1708528 - Caterpillar

Illustration 1 g03811279
Illustration 2 g03811269
Starter Motor Relay connections
This diagnostic code is associated with the Starter Motor Relay. The FMI 03 diagnostic code means that the ECM has detected that voltage is present in the relay circuit when the output driver is OFF.The possible causes of the diagnostic code are listed below:
The power circuit of the relay is shorted to another voltage source circuit.
The Machine ECM has failed. This situation is unlikely.Note: Before performing this procedure, inspect the harness connectors that are involved in the 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. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure. Note: The following test procedure may cause other diagnostic codes to activate. Ignore these created diagnostic codes and clear these diagnostic codes when the original problem has been corrected.Test Step 1. Check The RelayNote: A faulty relay coil most likely will not cause an FMI 03 diagnostic code overvoltage condition. Do a basic check of the relay coil resistance, this code could indicate a future problem.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the harness connectors J1 from the Machine ECM and J1 from the Engine ECM.
At harness connectors J1 from the Machine ECM and J1 from the Engine ECM, measure the relay coil resistance. The measure the resistance between the energize contact J1-6 (wire 306-GN(Green)) (Machine ECM) and return contact J1-5 (wire H808-WH(White)) (Engine ECM). Expected Result:The resistance of the relay coil should measure between 81 to 113 ohms 3 ohms at 25° C (77° F). A small allowance can be made for extreme temperature measurements.Results:
OK - The resistance measurement of the relay coil is within the acceptable range. Proceed to Test Step 2.
NOT OK - The resistance measurement of the relay coil is NOT within the acceptable range.Repair: The relay is faulty. Replace the Starter Motor Relay. After the relay has been replaced, verify that the new relay corrected the problem before operating the machine.STOPTest Step 2. Check The Power Circuit Of The Relay For A ShortThe machine harness connectors remain disconnected from the Machine ECM.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the "Starter Motor" Relay.
At the machine harness connector for the Machine ECM, measure the resistance from contact J1-6 (wire 306-GN(Green)) to all of the contacts used in the machine harness connectors for the Machine and Engine ECM. Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.
NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J1-6 (wire 306-GN(Green)) and the circuit that has a low resistance measurement.Repair: Refer to the