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| Illustration 1 | g02681796 |
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Connections of the High Beams relay | |
This diagnostic code is associated with the High Beams relay. The relay is controlled by the Relay Driver Module through an "ON/OFF" output driver circuit. This driver circuit will also illuminate the High Beams indicator on the Instrument Cluster. The FMI 06 diagnostic code means that the Relay Driver Module has detected an above normal current in the relay circuit. The diagnostic code is activated on the Implement ECM via CAN Datalink.
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 Relay Driver Module 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 3071 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When the relay is disconnected from the harness, the CID 3071 FMI 06 diagnostic code is no longer active. A CID 3071 FMI 05 is now active.
Results:
- YES - When the relay is disconnected from the harness, the CID 3071 FMI 06 diagnostic code is no longer active. A CID 3071 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 3071 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 connector J1 from the Relay Driver Module.
- At the machine harness connector J1 for the Relay Driver Module, measure the resistance from contact J1-14 (wire A608-GY(Grey)) to frame ground. Measure the resistance from contact J1-14 (wire A608-GY(Grey)) to all of the other contacts that are used in the machine harness connector J1 for the Relay Driver Module.
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 A608-GY(Grey) and the circuit that has a low resistance measurement.
Repair: Refer to the complete Electrical System Schematic of the machine. Check all of the connectors that are in the relay circuit. Ensure that all connections are clean, that all connections are secure and that all connections are in good condition.
For information on testing for short circuits and finding short circuits, refer to Testing and Adjusting, "Wiring Harness (Short Circuit) - Test". Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Inspect the harness connectors. Clean the contacts of the harness connectors. Check the wires for damage to the insulation that can be caused by excessive heat, battery acid, or chafing.
- Perform a
45 N (10 lb) pull test on each of the wires that are associated with the circuit. - Reconnect all harness connectors in order to make sure that the connectors are fully seated and locked.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Determine if the CID 3071 FMI 06 diagnostic code is active.
Expected Result:
The CID 3071 FMI 06 diagnostic code is no longer active.
Results:
- YES - The CID 3071 FMI 06 diagnostic code is not active. The problem does not exist at this time.
Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at a harness connector that was disconnected and reconnected. Resume normal machine operation.
STOP
- NO - The CID 3071 FMI 06 diagnostic code is active. The problem has not been corrected.
Repair: Check the relay circuit again. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.
If the cause of the problem is not found, the Relay Driver Module may have failed.
Prior to replacing an ECM/RDM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may effect repair time. If the cause of the diagnostic code is not found, replace the ECM/RDM. Refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".
STOP