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TM 5-3805-293-23-1
FIELD MAINTENANCE
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TROUBLESHOOTING INTRODUCTION
0004
INTRODUCTION
N OT E
Before beginning a task, find out how much repair, modification, or replacement is needed
to fix equipment as described in this manual. Sometimes the reason for equipment failure
can be seen right away and complete teardown is not necessary. Disassemble equipment
only as far as necessary to repair or replace damaged or broken parts.
1. This chapter provides information for identifying and correcting malfunctions that may develop during operation
of the 120M Motor Grader.
2. The Troubleshooting Symptom Index in WP 0010 lists common malfunctions and refers to the corresponding
pages in the Troubleshooting Procedures.
3. If you are unsure of the location of an item mentioned in troubleshooting, refer to the General Information work
package (WP 0001), or Equipment Description and Data work package (WP 0002).
4. Before performing troubleshooting, read and follow all safety instructions found in the Warning Summary at the
front of this manual.
5. The Troubleshooting Symptom Index (WP 0010) cannot list all malfunctions that may occur, nor can trouble-
shooting procedure list all tests or inspections and corrective actions.
6. Document all of the codes and symptoms before troubleshooting. Refer to How To Use On-Board Diagnostics
(WP 0005) to retrieve diagnostic and event codes using the Messenger. In order to troubleshoot diagnostic or
event codes, connect the MSD (WP 0006), and determine whether diagnostic or event codes are active. If
diagnostic or event codes are active, proceed to Troubleshooting Symptom Index (WP 0010) for list of diagnos-
tic and event codes. Some codes may be set in the course of testing and should not be diagnosed in addition
to those noted before testing.
7. When troubleshooting a malfunction:
a. Locate the symptom or symptoms in Troubleshooting Symptom Index (WP 0010) that best describe the
malfunction.
b. Turn to the page in where the troubleshooting procedures for the malfunction in question are described.
c.
Perform the task, answer the question, and perform the corrective action in the order listed until the mal-
function is corrected. Do not perform any maintenance tasks unless the troubleshooting procedure tells
you to do so.
EXPLANATION OF COLUMNS
The columns in the troubleshooting table are defined as follows:
a. MALFUNCTION. A visual or operational indication that something is wrong with the equipment.
b. TEST OR INSPECTION. A procedure to isolate the problem in a system or component.
c.
CORRECTIVE ACTION. A procedure to correct the problem.
END OF WORK PACKAGE
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