P0404

P0404-EGR POSITION SENSOR PERFORMANCE




For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation

The Exhaust Gas Recirculation (EGR) Valve contains three hall effect sensors to detect position. The three position sensors correspond to six valid sectors that the valve can be in. If the valve position skips a sector(s), a fault counter is incriminated, else decremented. Once the counter equals a calibrated threshold, the rationality fault becomes active. The position sensors are integral to the valve assembly and are not serviced separately. The Engine Control Module (ECM) will light the MIL lamp once the diagnostic runs and fails in two consecutive drive cycles. The ECM will turn off the MIL lamp once the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
Key on, engine off AND while running.

- Set Condition:
EGR solenoid internal position reading does not follow expected values.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

OTHER DTCS
1. Ignition on engine off.
2. With a scan tool, read DTCs.

Do you have any additional EGR related DTCs?

Yes

- Repair all other DTCs first

No

- Replace EGR Valve.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.