S8 - Check EGR Vacuum
- Disconnect vacuum line at EGR valve, and plug the vacuum line.
- Start engine.
NOTE: When verifying drive symptom, a Diagnostic Trouble Code (DTC) may be stored in memory; erase Continuous Memory after performing this procedure. Clearing Diagnostic Trouble Codes
- For Drive Symptom: Was drive symptom eliminated?
- For No Start: Does engine start?
Yes -- For vehicles with Differential Pressure Feedback EGR (DPFE): Go to DL50. DL50 - Code 336 or 337: Check For EVR Malfunction
For vehicles with Pressure Feedback EGR (PFE): Go to DL21. DL21 - Rerun Self-Test w/EGR Vacuum Line Disconnected
No -- Go to S9. S9 - Check EGR Valve