P0401- EGR SYSTEM PERFORMANCE
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the engine running.
- Set Condition:
The ECM detects and EGR flow problem for 8.0 seconds
| Possible Causes |
| INTERMITTENT CONDITION |
| EGR VALVE |
| INTAKE OR EXHAUST SYSTEM PROBLEM |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. VERIFY ACTIVE DTCWith the scan tool, erase ECM DTCs
Test drive the vehicle.
With the scan tool, read ECM DTCs
Did this DTC set again?
Yes
- Refer to symptom CHECKING THE EGR SYSTEM for further diagnosis.
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)