Note. For circuit reference (Схема №10)
Circuit Description
EGR system is used to reduce NOx (Oxides of Nitrogen) levels. This system uses a linear EGR valve. Using inputs from various sensor, PCM controls EGR pintle position and can be monitored with scan tool. Actual EGR position should always be near the commanded or desired EGR position. If PCM detects a large difference between desired and actual EGR position, DTC P0404 will be set. DTC P0404 is a type "B" code.
Conditions required to set DTC are
- IAT is above 41°F (5°C).
- Engine speed is less than 500 RPM.
- EGR pintle position is greater than 55 counts.
Diagnostic Aids
Inspect for poor connections or damaged connectors. Using scan tool, observe EGR POSITION while performing a wiring harness wiggle test. Ensure EGR is properly mounted. Check for signs of restricted exhaust. Check FREEZE FRAME ECT sensor data to determine if vehicle was cold when DTC was set. Due to moisture in exhaust system, EGR valve may freeze or stick in cold climates.