DTC P0400-00: Exhaust Gas Recirculation "A" Flow; DTC P0401-9C: Exhaust Gas Recirculation "A" Low / Insufficient Flow; DTC P0402-9B: Exhaust Gas Recirculation "A" High/Excessive Flow [12/2021 - 11/2024]: Description

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Based on the driving conditions, the ECM regulates the volume of exhaust gas that is recirculated to each engine cylinder in order to lower the combustion temperature and reduce NOx emissions. The ECM monitors signals such as engine speed, engine coolant temperature, electric load, and vehicle speed. When the EGR permission conditions are met, the ECM controls the opening of the EGR valve linearly through signals to the EGR step motor.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P0400-00	Exhaust Gas Recirculation "A" Flow	During fuel cut, when the change in intake manifold pressure when the EGR valve assembly is operating and when not operating is insufficient (2 trip detection logic).	EGR valve assembly EGR passage EGR cooler assembly Intake system Manifold absolute pressure sensor	Comes on	DTC stored	SAE Code: P0400 DTC for Mexico Models: Does not apply
P0401-9C	Exhaust Gas Recirculation "A" Low / Insufficient Flow	During fuel cut, when the change in intake manifold pressure when the EGR valve assembly is operating and when not operating is insufficient, the intake manifold pressure is less than 31.99 (4.64 psi) kPa when the EGR valve assembly is not operating (1 trip detection logic) (except Mexico Models). Charge in intake manifold pressure is small when the EGR valve opened and closed during fuel cut operation (2 trip detection logic) (for Mexico Models).	EGR valve assembly EGR passage EGR cooler assembly Manifold absolute pressure sensor	Comes on	DTC stored	SAE Code: P0401 DTC for Mexico Models: Applies
P0402-9B	Exhaust Gas Recirculation "A" High/Excessive Flow	During fuel cut, when the change in intake manifold pressure when the EGR valve assembly is operating and not operating is insufficient, the intake manifold pressure is 31.99 kPa (4.64 psi) or more when the EGR valve assembly is not operating (1 trip detection logic).	EGR valve assembly EGR passage Intake system Manifold absolute pressure sensor	Comes on	DTC stored	SAE Code: P0402 DTC for Mexico Models: Does not apply

HINT:

DTC P0401-9C or DTC P0402-9B will only be stored when DTC P0400-00 is stored in the second trip (except Mexico Models).