Navistar N9 Diagnostic Manual page 6

2
Service Diagnosis
Service diagnosis is an investigative procedure that must be followed to find and correct an engine application
problem or an engine problem.
If the problem is engine application, see specific vehicle manuals for further diagnostic information.
If the problem is the engine, see specific Engine Diagnostic Manual for further diagnostic information.
Prerequisites for Effective Diagnosis
• Availability of gauges and diagnostic test equipment
• Availability of current information for engine application and engine systems
• Knowledge of the principles of operation for engine application and engine systems
• Knowledge to understand and do procedures in diagnostic and service publications
Technical Service Literature required for Effective Diagnosis
• Engine Service Manual
• Engine Diagnostic Manual
• Engine and Aftertreatment Wiring Schematic Form
• Service Bulletins
DIAGNOSTIC MANUAL