Possible causes include:
Faulty EGR valve
Vacuum leak in the EGR system
Faulty EGR position sensor
Faulty ECM
To diagnose the cause of the code, a mechanic will typically:
Check the EGR valve for proper operation
Check the vacuum lines for leaks
Test the EGR position sensor
Scan the ECM for other trouble codes
Based on the results of the tests, the mechanic will then recommend the appropriate repairs.
