2-13. INTRODUCTION TO LOGIC TREE TROUBLESHOOTING (CONT)
(d) QUESTION Each question, located in the middle column, refers to the first possible problem listed in
POSSIBLE PROBLEMS. If the answer to the question is YES, proceed to the next step. If the answer is NO, follow the NO
arrow to obtain directions for correcting the problem. If the step contains a WARNING or CAUTION message, a small
shadow box is printed above the question. Text for WARNINGS and CAUTIONS is on the following right-hand page.
(e) TEST OPTIONS This box is located in the right-hand column and lists the test(s) to be performed.
(f) REASON FOR QUESTION This box is located directly below TEST OPTIONS. It explains the purpose
for the question in the middle column.
(2) A test page is always a right-hand page, facing the logic tree page on the left. The test provides detailed instructions
for testing the first component listed in the POSSIBLE PROBLEMS box. This test will also provide an answer for the question
in the middle column. Note the arrow connecting the test on the right-hand page to the REASON FOR QUESTION. When
possible, illustrations are included to provide visual details. Warnings, cautions, and notes contain additional information for
b. How to Begin Troubleshooting.
(1) Determine the symptom or condition that indicates a problem or failure. Troubleshooting is divided into symptoms
peculiar to a system or a component, for example: hydraulic system or engine. Refer to the Troubleshooting Fault Index (Table
(2) Go to the referenced page to begin troubleshooting. Open the manual flat so both the left-hand and right-hand pages
are displayed before you. The information on both pages is important to resolve the problem or failure. However, the
experienced technician can follow the left-hand page instructions and refer to the right-hand page when necessary.
(3) Follow the diagnostic procedure. Answer question No. 1 on the left-hand page and follow the YES or NO path to
either the remedy or the next question. If necessary, look on the right-hand page for test instructions and illustrations.
(4) Observe warnings, cautions and notes. The formatting symbols used in this manual for warnings, cautions and notes
are as follows:
This is the symbol for a warning statement. If you see the word WARNING above a question on the
left-hand page, look on the right hand page for the text of the message. WARNINGS describe a
situation which could cause severe injury or death to personnel.
This is the symbol for a caution statement. If you see the word CAUTION above a question on the
left-hand page, look on the right-hand page for the text of the message. CAUTIONS describe a
situation which could cause damage to equipment.
This is the symbol for a note. Notes are located directly above the test to which they refer. Notes
provide additional information for performing a test.