Component Location
General Description

Receiving ECM signal, linear solenoid type electronic EGR actuator operates EEGR valve directly. ECM performs EGR system feed back control with the information of measured mass air flow. (The role of MAFS in diesel engine is different from gasoline engine. Fuel injection quantity is decided by MAFS signal in gasoline engine.) When EGR gas(contains no oxygen) flowing into combustion chamber increases, the air passing through MAFS(contains oxygen) decreases. Thus, with the output signal change of MAFS accompanied by EEGR actuator actuation, ECM determine the amount of recirculated EGR gas quantity.

note

NOx is produced from the reaction of nitrogen and oxygen. Controlling EGR gas(contains no oxyger) which is recirculated to combustion chamber, if least intake air required for complete combustion flows into combustion chamber, NOx decreases because there is no supplementary oxygen to react with nitrogen.

DTC Description

P401 is set when ECM/PCM detects that duty amount of EEGR actuator contol valve, ENG speed or amount of EGR is exceeded to minimum set point last to more than 20sec. In this case, check that stuck of EEGR actuator, air leakage of intake line.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

● Signal monitoring

● EGR actuator stuck

● EGR actuator component

● Air leakage of intake line

Enable Conditions

● Engine running

Threshold Value

● EGR is exceeded to minimum set point

Diagnostic Time

● 20 sec.

Fail Safe

Fuel Cut

NO

EGR Off

YES

Fuel Limit

NO

MIL

OFF

Specification

EGR actuator component resistance

EGR actuator operating Hz

EGR actuator operating duty

7.3~ 8.8Ω (30℃)

142Hz

approx.10%(closed)~40%(opened)

Schematic Diagram
note
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Signal Waveform
note

The output of approx. 10% duty is mainly for the diagnosis of EEGR actuator circuit than actuating EEGR.

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