320 GX and 323 GX Excavator Machine Systems Troubleshooting Relay

Relay - Test

320 GX and 323 GX Excavator Machine Systems Troubleshooting [M0120175]

320 GX and 323 GX Excavator Machine Systems Troubleshooting Connector Contact Description

320 GX and 323 GX Excavator Machine Systems Troubleshooting Sensor Signal (Analog, Passive) - Test

ELECTRICAL AND STARTING SYSTEM

SWITCH GP

320 GX and 323 GX Excavator Machine Systems Troubleshooting Operator Control Switch (Switch to Battery) - Test

320 GX and 323 GX Excavator Machine Systems Troubleshooting Relay - Test

1.1. Machine ECM 1

2.1. Diagnostic Trouble Code Procedure

3.1. FMI 3

4.1. FMI 5

5.1. FMI 6

6.1. FMI 11

Machine ECM 1

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the relays of the machine.

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Table 1
Machine ECM 1 (MID 299)
J1939	CDL	Code Description	System Response
	781-3	Lighting Relay : Voltage Above Normal	Related lighting system will be ON continuously.
	781-5	Lighting Relay : Voltage Below Normal	Related lighting system will be ON continuously.
	781-6	Lighting Relay : Current Above Normal	Related lighting system will be ON continuously.
	781-11	Lighting Relay : Failure Mode Not identifiable	Related lighting system will be ON continuously.
	3068-3	Beacon Relay: Voltage Above Normal	Beacon cannot be activated.
	3068-5	Beacon Relay: Current Below Normal	Beacon cannot be activated.
	3068-6	Beacon Relay: Current Above Normal	Beacon will remain activated and cannot be deactivated.
	3068-11	Beacon Relay: Failure Mode Not Identifiable	Beacon will remain activated and cannot be deactivated.
	3467-3	Main Power Relay: Voltage Above Normal	Machine electrical systems are disabled.
	3467-5	Main Power Relay: Current Below Normal	Machine electrical systems are disabled.
	3467-6	Main Power Relay: Current Above Normal	Machine electrical systems are disabled.
	3467–11	Main Power Relay: Failure Mode Not identifiable	Machine electrical systems are disabled.
	3634-3	Boom Light Relay: Voltage Above Normal	Related lighting system will be ON continuously.
	3634-5	Boom Light Relay: Current Below Normal	Related lighting system will be ON continuously.
	3634-6	Boom Light Relay: Current Above Normal	Related lighting system will be ON continuously.
	3634-11	Boom Light Relay: Failure Mode Not identifiable	Related lighting system will be ON continuously.

A relay is a component that uses a small amount of electrical current to control a large amount of electrical current.

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Illustration 1	g06607887
Relay circuit schematic

The preceding diagram is a simplified schematic of the relay connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic to view the entire circuitry of the machine.

Diagnostic Trouble Code Procedure

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Table 2
Required Tools
Tool	Part Number	Description	Qty
T1	146-4080⁽¹⁾	Digital Multimeter Group	1
	8T-3224	Needle Tip Group	1
	7X-1710	Multimeter Probe Group	1
	8T-8726	Cable Assembly (Three Pin) (3-Pin Breakout)	1
T2	JERD2129	Cat^® Electronic Technician (Cat ET)	1
		Windows-based PC	1
	466-6258	Communication Adapter Gp	1
T3	6V-4148	Connector Repair Kit (Sure Seal)	1
T4	190-8900	Connector Field Repair Kit (Deutsch)	1
T5	175-3700	Connector Repair Kit Deutsch DT	1

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⁽¹⁾	This multimeter can use an RS232C cable to connect to a Laptop computer or Dataview tool gp for troubleshooting.

Prior to beginning this procedure, inspect the harness connectors that are involved in this 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. Check the wiring harness for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure.

Identify the active FMI code associated with the components.
Determine which code is present and use the list below to determine which procedure to follow.

FMI 3 Diagnostic code, proceed to "FMI 3".
FMI 5 Diagnostic code, proceed to "FMI 5".
FMI 6 Diagnostic code, proceed to "FMI 6".
FMI 11 Diagnostic code, proceed to "FMI 11".

FMI 3

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Table 3
Check The Machine Harness For A Short
Troubleshooting Test Steps	Values	Results
1. Turn the start switch and disconnect switch to the OFF position. 2. Disconnect the relay from the harness. 3. Disconnect the ECM machine harness connectors. 4. 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 5KΩ.	Result: All resistance measurements are greater than 5K Ω. Proceed to "Check If The Diagnostic Code Remains" Table 4. Result: One or more readings are less than 5 Ω. Repair: A short exists between the signal contact and the circuit with the low resistance. Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. Proceed to "Check If The Diagnostic Code Remains" Table 4.

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Table 4
Check If The Diagnostic Code Remains
Troubleshooting Test Steps	Values	Results
1. Reconnect all harness connectors. Return machine to normal operating condition. 2. Turn the start switch and the disconnect switch to the ON position. 3. Clear all diagnostic codes. 4. Operate the machine. 5. Stop the machine and engage the safety lock. 6. Check if the diagnostic code is active.	The diagnostic code is no longer present.	Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. Result: The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP.

FMI 5

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Table 5
Check The Relay
Troubleshooting Test Steps	Values	Results
1. Turn the start switch and disconnect switch to the OFF position. 2. Disconnect the relay from the wiring harness. 3. At the machine harness connector for the relay, place a jumper wire between the signal wire and the signal return. 4. Turn the start switch and the disconnect switch to the ON position. Do not start the engine. 5. Observe the status of the diagnostic code.	The diagnostic code changes from an FMI 5 to an FMI 6 after the jumper wire is installed.	Result: The harness is correct. The diagnostic code changes from an FMI 5 to an FMI 6 after the jumper wire is installed. The relay has failed. Repair - Replace the relay. Proceed to "Check If The Diagnostic Code Remains" 7. Result: The diagnostic code remains active. Proceed to "Check The Harness For An Open" Table 6.

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Table 6
Check The Harness For An Open
Troubleshooting Test Steps	Values	Results
1. Turn start switch and disconnect switch to the OFF position. 2. Disconnect the machine harness connectors from the ECM. 3. The jumper wire remains installed. 4. At the ECM machine harness connector, measure the resistance between the signal contact and the return contact.	The resistance is less than 5 Ω.	Result: The resistance is less than 5 Ω. The machine harness is correct. Proceed to "Check If The Diagnostic Code Remains" 7. Result: The resistance is greater than 5 Ω. The resistance measurement is not correct. There is an open circuit in the machine harness. Repair: 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. Proceed to "Check If The Diagnostic Code Remains" 7.

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Table 7
Check If The Diagnostic Code Remains
Troubleshooting Test Steps	Values	Results
1. Reconnect all harness connectors. Return machine to normal operating condition. 2. Turn the start switch and the disconnect switch to the ON position. 3. Clear all diagnostic codes. 4. Operate the machine. 5. Stop the machine and engage the safety lock. 6. Check if the diagnostic code is active.	The diagnostic code is no longer present.	Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. Result: The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP.

FMI 6

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Table 8
Check The Relay
Troubleshooting Test Steps	Values	Results
1. Turn the start switch and disconnect switch to the ON position. 2. Observe the status of the diagnostic code. 3. Disconnect the relay from the machine harness.	The FMI 6 changes to FMI 5 when the relay is disconnected.	Result: FMI 6 changes to FMI 5 when the relay is disconnected. The harness is correct. The relay has failed. Repair: Repair or replace the relay. Proceed to "Check If The Diagnostic Code Remains" Table 10. Result: The diagnostic code remains active. Proceed to "Check The Return Circuit For A Short To Ground" Table 9.

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Table 9
Check The Return Circuit For A Short To Ground
Troubleshooting Test Steps	Values	Results
1. Turn start switch and disconnect switch to the OFF position. 2. The relay remains disconnected from the machine harness. 3. Disconnect the machine harness connectors from the ECM. 4. 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 5K Ω.	Result: Each resistance measurement is greater than 5K Ω. The machine harness is correct. Proceed to "Check If The Diagnostic Code Remains" Table 10. Result: Each resistance measurement is not greater than 5K 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 corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. Proceed to "Check If The Diagnostic Code Remains" Table 10.

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Table 10
Check If The Diagnostic Code Remains
Troubleshooting Test Steps	Values	Results
1. Reconnect all harness connectors. Return machine to normal operating condition. 2. Turn the start switch and the disconnect switch to the ON position. 3. Clear all diagnostic codes. 4. Operate the machine. 5. Stop the machine and engage the safety lock. 6. Check if the diagnostic code is active.	The diagnostic code is no longer present.	Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. Result: The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. Follow the steps in Troubleshooting , "ECM - Replace" if the ECM needs to be replaced. STOP.

FMI 11

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Table 11
Check The Travel Alarm
Troubleshooting Test Steps	Values	Results
1. Turn the start switch and the disconnect switch OFF. 2. Disconnect the relay from the machine harness. 3. Place a jumper wire between contact 1 and contact 2, at the harness connector for the relay. 4. Turn the start switch and the disconnect switch ON. Do not start the engine. 5. 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.	Result: The circuit is correct. The relay has failed. Repair: Replace the relay. Proceed to "Check If The Diagnostic Code Remains" 13. Result: The diagnostic code remains active. Proceed to "Check The Harness For An Open" 12.

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Table 12
Check The Harness For An Open
Troubleshooting Test Steps	Values	Results
1. Turn start switch and disconnect switch to the OFF position. 2. Disconnect the machine harness connectors from the ECM. 3. The jumper wire remains installed. 4. At the ECM machine harness connector, measure the resistance between the signal contact and the return contact.	The resistance is less than 5 Ω.	Result: The resistance is less than 5 Ω. The machine harness is correct. Proceed to "Check If The Diagnostic Code Remains" 13. Result: The resistance is greater than 5 Ω. The resistance measurement is not correct. There is an open circuit in the machine harness. Repair: 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. Proceed to "Check If The Diagnostic Code Remains" 13.

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Table 13
Check If The Diagnostic Code Remains
Troubleshooting Test Steps	Values	Results
1. Reconnect all harness connectors. Return machine to normal operating condition. 2. Turn the start switch and the disconnect switch to the ON position. 3. Clear all diagnostic codes. 4. Operate the machine. 5. Stop the machine and engage the safety lock. 6. Check if the diagnostic code is active.	The diagnostic code is no longer present.	Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. Result: The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time. Follow the steps in Troubleshooting , "ECM - Replace" if the ECM needs to be replaced. STOP.