On some OBD-II vehicles, the EGR system can be controlled using the active test feature of the Diagnostic Tester. This is the easiest way to verify EGR system operation and can generally be performed as follows:
• Start the engine and allow it to reach operating temperature
• Using the Diagnostic Tester, access the Active Test menu
• Select "EGR System" from the Active Test menu
• Raise engine speed and maintain a steady 3000 rpm
• You should notice a slight drop in engine speed and a rise in EGRT gas temperature as EGR is activated
If engine speed and EGRT gas temperature does not change, the EGR system is not functioning and the problem may be mechanical or electrical. If the rpm drop is very slight, the problem may be a partially blocked or restricted EGR passage.
Was this article helpful?