374F and 390F Excavators and 390F MHPU Mobile Hydraulic Power Unit Alarm

Alarm - Test

374F and 390F Excavators and 390F MHPU Mobile Hydraulic Power Unit [UENR2724]

374F and 390F Excavators and 390F MHPU Mobile Hydraulic Power Unit General Information

374F and 390F Excavators and 390F MHPU Mobile Hydraulic Power Unit Connector Contact Description

ELECTRICAL AND STARTING SYSTEM

ALARM GP

374F and 390F Excavators and 390F MHPU Mobile Hydraulic Power Unit Alarm - Test

1.1. Machine ECM

2.1. Diagnostic Trouble Code Procedure

Machine ECM

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

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Table 1
Machine ECM (MID 299)
DTC	Code Description	System Response
376-3	Travel Alarm : Voltage Above Normal	The ECM will prevent the operator from engaging the machine in the reverse direction.
376-5	Travel Alarm : Current Below Normal	The ECM will prevent the operator from engaging the machine in the reverse direction.
376-6	Travel Alarm : Current Above Normal	The ECM will prevent the operator from engaging the machine in the reverse direction.

Possible causes for an FMI 3 diagnostic code are:

The travel alarm is shorted to a + battery source.
The Machine ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 5 diagnostic code are:

The energize circuit of the travel alarm is open.
The return circuit of the travel alarm is open.
The travel alarm has failed.
The Machine ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 6 diagnostic code are:

The travel alarm circuit is shorted to ground
The travel alarm has failed.
The Machine ECM has failed. A failure of the ECM is unlikely.

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Illustration 1	g03436676
Travel Alarm Circuit

Note: The diagram above is a simplified schematic of the Travel Alarm connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR2487 (374F) or Electrical Schematic, UENR2489 (390F) for the complete schematic.

Diagnostic Trouble Code Procedure

Note: 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. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Identify The Active FMI Code Associated With The Solenoid Circuit	Code present	FMI 3 diagnostic code, Proceed to Test Step 2. FMI 5 diagnostic code, proceed to Test Step 3. FMI 6 diagnostic code, proceed to Test Step 5.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Signal Circuit For A Short A. Key start switch and disconnect switch OFF. B. Disconnect the harness connector from the switch panel. C. Disconnect the travel alarm from the machine harness. D. At the connector for the switch panel measure the resistance between the travel alarm pin location and all sources for +battery.	Each reading is greater than 5K Ω.	OK - All measurements are greater than 5K Ω. Proceed to Test Step 7. NOT OK - Resistance is less than 5 Ω, a short exists in signal circuit. Repair: Repair or replace 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 Test Step 7.
Begin Procedure For FMI 5 Troubleshooting HERE
3. Check The Alarm A. Key start switch and disconnect switch ON. Do NOT start the engine. B. Disconnect alarm from machine harness. C. At harness connector for alarm, place jumper wire between pin 1 and pin 2. D. Observe status of diagnostic code.	Code for alarm circuit remains active.	OK - Diagnostic code remains active, jumper wire does not affect diagnostic code. Proceed to Test Step 4. NOT OK - Diagnostic code is no longer active, alarm has failed. Repair: Replace the alarm. Verify that new alarm corrects problem. Proceed to Test Step 7.
4. Check The Harness For An Open A. Key start switch and disconnect switch OFF. B. Disconnect harness connectors from switch panel. C. Jumper wire from previous test remains installed. D. At switch panel harness connector measure resistance from signal contact to ground contact.	The reading is less than 5 Ω.	OK - The reading is less than 5K Ω, the machine harness is correct. Proceed to Test Step 7. NOT OK - The reading is greater than 5K Ω. The circuit is open in the machine harness. Repair : Open is in the wire for the solenoid signal or the return wire for the solenoid. 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 Test Step 7.
Begin Procedure For FMI 6 Troubleshooting HERE
5. Check The Travel Alarm A. Key start switch and disconnect switch ON. Do NOT start the engine. B. Check that diagnostic code is active. C. Disconnect travel alarm from machine harness. D. Confirm status of diagnostic code.	Code remains active -- no change.	OK - Diagnostic FMI 6 remains active. Proceed to Test Step 6. NOT OK - Diagnostic code changes from FMI 6 to FMI 5. Repair: Replace the travel alarm. Proceed to Test Step 7.
6. Check The Signal Circuit For A Short To Ground A. Key start switch and disconnect switch OFF. B. Disconnect machine harness at travel alarm. C. Disconnect all harness connections at switch panel. D. At switch panel harness connector measure resistance from signal contact of travel alarm to all possible sources of ground.	All readings are greater than 5K Ω.	OK - All resistance greater than 5K Ω. Proceed to Test Step 7. NOT OK - One or more readings less than 5 Ω. Repair -Short between signal contact and the circuit with the low resistance. 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 Test Step 7.
7. Check If The Diagnostic Code Remains. A. Key start switch and disconnect switch ON. B. Clear all diagnostic codes. C. Operate the machine in reverse. D. Stop machine and engage the safety lock lever. E. Check if diagnostic code for the travel alarm is active.	Code for solenoid is NO longer present.	OK - Diagnostic code does not exist at this time. Initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - Diagnostic trouble code has not been corrected. Repair: If the diagnostic code continues to exist after performing the procedure a second time, follow procedure for replacing the ECM. Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may greatly effect repair time. Follow the steps in Troubleshooting, "Electronic Control Module (ECM) - Replace" if the ECM needs to be replaced.