Note. If EGR valve shows signs of excessive heat, check exhaust system for restriction or blockage (possible plugged catalytic converter).
Circuit Description
PCM monitors EGR valve pintle position input to ensure EGR valve responds properly to commands from PCM. If PCM detects a pintle position signal voltage less than normal range of pintle position sensor, or a signal voltage that is not within a tolerance considered acceptable for proper EGR system operation, PCM will set DTC P1404.
Conditions required for setting this DTC are
- Intake air temperature is greater than 41°F (5°C).
- EGR actual position is 16 counts less than EGR low threshold for a least 3 iterations per 5 seconds.
Diagnostic Aids
Check for excessive deposits on EGR valve pintle or pintle seat, or deposits that would prevent pintle from extending completely or to stick. Check for damage to wiring harness. While observing scan tool display for EGR position, move all connectors and wiring harnesses related to EGR system. A change in displayed value should indicate approximate location of fault.