Symptom Related Diagnostic Procedures

RESULTS OF INCORRECT OPERATION
With too much EGR flow at idle, cruise, or cold operation, any of the following conditions may occur:
- Engine stops after cold start.
- Engine stops at idle after deceleration.
- Vehicle surges during cruise.
- Rough idle.

Too little or no EGR flow allows combustion temperatures to get too high during acceleration and load conditions. This could cause:
- Spark knock (detonation).
- Engine overheating.
- The setting of Diagnostic Trouble Code (DTC) P0401.