ENGINE AR-PRIMARY 4607169 - Caterpillar

Illustration 1 g02594937
Connections of the Machine Power Distribution Relay
This diagnostic code is associated with the Machine Power Distribution Relay. The FMI 06 diagnostic code is activated when the ECM detects that the current in the relay circuit is above normal.The conditions that could cause this diagnostic code to activate are listed:
The relay has failed.
The energize circuit of the relay is shorted to a ground source.
The ECM has failed. This condition 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, that all connections are secure, and that all connections are 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 be activated. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Test Step 1. CHECK THE RELAY
Turn the key start switch and the disconnect switch to the ON position.
Observe the status of the active CID 3470 FMI 06 diagnostic code and disconnect the machine harness connector from the relay.Expected Result:When the relay is disconnected from the harness, the CID 3470 FMI 06 diagnostic code is no longer active. A CID 3470 FMI 05 is now active.Results:
YES - When the relay is disconnected from the harness, the CID 3470 FMI 06 diagnostic code is no longer active. A CID 3470 FMI 05 diagnostic code becomes active. The relay is the cause of the problem.Repair: Verify that the relay has failed by substituting a known good relay that is the same part number as the faulty relay. Replace the faulty relay.STOP
NO - The status of the active CID 3470 FMI 06 diagnostic code did not change when the relay was disconnected from the machine harness. The relay is not the cause of the problem. Proceed to Test Step 2.Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE RELAY FOR A SHORTThe relay remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector J2 from the Relay Driver Module.
At the machine harness connector J2 for the ECM, measure the resistance from contact J2-6 (wire X721-BR(Brown)) to frame ground. Measure the resistance from contact J2-6 (wire X721-BR(Brown)) to all the other contacts used in the Relay Driver Module machine harness connector J2.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The energize circuit is not shorted to another circuit in the machine harness. 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 wire X721-BR(Brown)and the circuit that has a low-resistance measurement.Repair: Refer to the complete Electrical System Schematic of the machine. Check