EGR Valve: Testing and Inspection

The diagnosis of the Exhaust Gas Recirculation (EGR) system is part of the control module system and starts with the "On-Board Diagnostic System Check." This will determine if the system is operating correctly. If the EGR system is not working properly, the "On-Board Diagnostic System Check" will direct diagnosis to a Diagnostic trouble Code (DTC) tree chart or to another system circuit. Refer to C Charts. Under Computers and Control Systems/System Diagnosis. Testing and Inspection