SEAL AS 7J4820 - Caterpillar

Illustration 1 g02526297
Relay Connections for the Secondary Steer RelayThis diagnostic code is associated with the relay for the Secondary Steer Relay. The relay is controlled by the Transmission/Chassis ECM through an "ON/OFF" output driver. The FMI 06 diagnostic code means that the ECM has energized the output for the relay and the current for the relay circuit is above normal.The conditions that could cause this diagnostic code to activate are listed below:
The relay has failed.
The energize circuit of the relay is shorted to a ground source.
The Transmission/Chassis 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, 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 0420 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from the relay.Expected Result:When the relay is disconnected from the harness, the CID 0420 FMI 06 diagnostic code is no longer active. A CID 0420 FMI 05 diagnostic code is now active.Results:
YES - When the relay is disconnected from the harness, the CID 0420 FMI 06 diagnostic code is no longer active. A CID 0420 FMI 05 diagnostic code becomes active. The relay is the cause of the problem. Repair: Replace the faulty relay.STOP
NO - The status of the active CID 0420 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 SHORT The relay remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors J1 and J2 from the "Transmission/Chassis ECM".
At the machine harness connector J2 for the ECM, measure the resistance from contact J2-6 (wire K748-OR) to frame ground. Measure the resistance from contact J2-6 (wire K748-OR) to all of the other contacts that are used in the machine harness connectors J1 and J2 for the ECM. 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 K748-OR and the circuit that has