GENERATOR AS 4752442 - Caterpillar

Table 3
FMI 5 Troubleshooting
Troubleshooting Test Steps Values Results
1. Check The Relay
A. Turn the start switch and the disconnect switch OFF.
B. Remove the relay.
C. Place a jumper wire between the signal contact and the return contact of the relay.
D. Turn the start switch and the disconnect switch ON. Do not start the engine.
E. As the jumper is removed and connected to the contacts, observe any code change.
The code changes to FMI 6 after the jumper wire is installed. OK: The circuit is correct. The relay has failed.
Repair: Replace the relay.
After replacement of the relay, confirm that the diagnostic code is not active.
STOP
NOT OK: The diagnostic code remains active.
Proceed to Test Step 2.
2. Check The Return Circuit For A Short To Ground
A. Turn the start switch and the disconnect switch OFF.
B. Disconnect the harness connectors from the ECM.
C. The jumper wire remains installed.
D. At the machine harness connector for the ECM, measure the resistance at the ECM contacts for the relay.
Each resistance measurement is less than 5 Ω. OK: The reading is less than 5 Ω, the harness is correct.
NOT OK: The reading is greater than 5K Ω. Circuit open in machine harness.
Repair: The open is in the wire for the relay signal or the return wire for the relay. Repair or replace the machine harness.
Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.
STOP
Table 4
FMI 6 Troubleshooting
Troubleshooting Test Steps Values Results
1. Check The Relay
A. Turn the start switch and disconnect switch to the ON position.
B. Observe the status of the diagnostic code.
C. Disconnect the relay from the machine harness.
The FMI 6 code is no longer active when the relay is disconnected. OK - The FMI 6 is no longer active when the relay is disconnected. The harness is correct. The relay has failed.
Repair: Repair or replace the relay.
Proceed to Test Step 3.
NOT OK - The diagnostic code remains active.
Proceed to Test Step 2.
2. Check The Return Circuit For A Short To Ground
A. Turn the start switch and disconnect switch to the OFF position.
B. The relay remains disconnected from the machine harness.
C. Disconnect the machine harness connectors from the ECM.
D. At the ECM machine harness connector, measure the resistance between the signal contact and all other contacts that are used in the ECM.
Each resistance measurement is greater than 5 Ω. OK - Each resistance measurement is greater than 5 Ω. The machine harness is correct.
Proceed to Test Step 3.
NOT OK - Each resistance measurement is not greater than 5 Ω. A short circuit exists between the signal circuit and the circuit with the low-resistance measurement.
Repair: Repair or replace the machine harness.
Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit.
Proceed to Test Step