How to Begin Troubleshooting. -726280197

TM 9-2320-364-20-1

How to Begin Troubleshooting.

(1)

Determine the symptom or condition that indicates a problem or failure. Troubleshooting is divided into

symptoms peculiar to a truck system or component, for example: air system or engine. Refer to the

Troubleshooting Fault Index (Table 2-15). Follow DDEC II and DDEC III/IV Troubleshooting BEFORE

going to Engine Troubleshooting.

(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 and 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.

NOTE

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.

Abbreviations and Commonly Used Terms.

(1)

A/D - Analog to Digital: The computer inside the DDEC ECM uses an A/D converter to convert a sensor

voltage into a number with which the computer can work.

(2)

Active Codes - These are the codes that currently keep the Check Engine Light on. They can only be

read using the Diagnostic Data Reader.

(3)

BAT - Battery.

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