525D, 535D, 545D and 555D Wheel Skidders Information Display Caterpillar

Alarm - Test

Usage:

555D 5L5

Monitoring System

The following is a list of codes that are associated with the active alarm circuit of the Monitoring System.

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Table 1
Monitoring System Display (MID 053)
DTC	Code Description	System Response
271-5	Action Alarm: Current Below Normal	The alarm will not sound along with a visual alarm.
271-6	Action Alarm: Current Above Normal	The alarm may sound constantly.

Note: The component identified in the troubleshooting table above is connected to the Monitoring System. The Monitoring System activates the alarms after receiving a signal from the J1939 Data Link. If a CID 247 is active, the troubleshooting for the J1939 Data Link must be performed before proceeding.

Possible causes for an FMI 5 diagnostic code are:

The energize circuit of the action alarm is open.
The return circuit of the action alarm is open.
The action alarm has failed.
The Monitoring System has failed. A failure of the Monitoring System is unlikely.

Possible causes for an FMI 6 diagnostic code are:

The action alarm circuit is shorted to ground
The action alarm has failed.
The Monitoring System has failed. A failure of the Monitoring System is unlikely.

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Illustration 1	g03677785

Note: The diagram above is a simplified schematic of the "Action Alarm" and "Action 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, KENR7524 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 Circuit	Code present.	FMI 5 diagnostic code, proceed to Test Step 2. FMI 6 diagnostic code, proceed to Test Step 4.
Begin Procedure For FMI 5 Troubleshooting HERE
2. Check The Alarm A. Turn the key start switch and disconnect switch ON. Do NOT start the engine. B. Disconnect alarm from machine harness. C. At harness connector for the alarm, place a jumper wire between connector 1 and connector 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 3. NOT OK - Diagnostic code changes from FMI 5 to FMI 6. Repair: Replace the alarm. Verify that the new alarm corrects the problem. STOP.
3. Check The Harness For An Open A. Turn the key start switch and disconnect switch OFF. B. Disconnect harness connectors from the Monitoring System Display. C. The jumper wire from the previous test remains installed. D. At the Monitoring System Display connector, measure the resistance from signal contact to ground contact.	The reading is less than 5 Ω.	OK - The reading is less than 5 Ω, the machine harness is correct. Proceed to Test Step 6. NOT OK - The reading is greater than 5K Ω. The circuit is open in the machine harness. Repair: The open is in the signal wire or the return wire for the alarm. 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 check of all connectors is required. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 6.
Begin Procedure For FMI 6 Troubleshooting HERE
4. Check The Action Alarm A. Turn the Key Start Switch and the Disconnect Switch ON. Do NOT start the engine. B. Check that the diagnostic code is active. C. Disconnect the 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 5. NOT OK - Diagnostic code changes from FMI 6 to FMI 5. Repair: Replace the alarm. Proceed to Test Step 6.
5. Check The Signal Circuit For A Short To Ground A. Turn the key start switch and disconnect switch OFF. B. Disconnect the machine harness at the alarm. C. Disconnect all harness connections at the switch panel. D. At switch panel harness connector measure resistance from signal contact of 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 6. 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. An inspection of all connectors is required. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 6.
6. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reinstall the alarm and reconnect all harness connectors. C. Turn the key start switch and disconnect switch ON. D. Clear all diagnostic codes. E. Operate the machine in reverse. F. Stop machine and engage the safety lock lever. G. Check if diagnostic code is active.	Code 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 a 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 Monitoring System Display. Prior to replacing the Monitoring System Display, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly affect repair time.