65678

Description

First of all check damage of terminals : Check terminals for contact resistance, corrosion and deformation. Before measuring resistance, you must calibrate(0Ω) the tester.

In case of abnormal 'Air mass meter' data, Inspect the EGR solenoid valve.

The EGR valve of R-engine is operated directly by cam controlled by DC motor. A position sensor detects cam position therefore EGR valve malfunction(stuck, not working properly) diagnosis is possible.

Diagnostic Procedure

EGR Actuator valve stuck inspection.

IG S/W 'OFF', ENGINE 'OFF'

Allow the engine to warm up to normal operating temperature.

Electrical system and A/CON 'OFF'.

Select 'Air Mass Flow' parameter on the scantool.

Measure waveform of terminal '4' of EGR actuator connector by using oscilloscope. (Do not disconnect)

When EGR actuator is 'OFF' (0.0%) at idle, Engine 'OFF'.

☞ Inspect EGR initial actuation signal and monitor position sensor waveform after Engine 'OFF'.

☞ EGR actuation signal is repeated 3 times from 0% to 30~40%.

☞ Position sensor waveform : According to EGR actuation signal, moved open and close 3 times by EGR actuator position sensor.

- EGR actuator 0%(close) : 4.0V

- EGR actuator 30~40%(close) : 2.5V

Symptom		Inspection procedure
Case1	● EGR Actuator valve is open stuck.	● Engine poor acceleration occurs and engine discharges black smoke, etc…because of excessive EGR gas recirculation. ☞ Replace EGR actuator, If symptom occurs again after EGR actuator valve cleaning.
Case2	● In case that EGR Actuator valve is close stuck.	● DTCs of EGR system are displayed and engine discharges excessive NOx, etc... because EGR gas can not be recirculated. ☞ Replace EGR actuator, If symptom occurs again after EGR actuator valve cleaning.
Case3	● In case that EGR Actuator valve is close stuck.	● DTCs of EGR system are displayed and engine discharges excessive NOx, etc... because EGR gas can not be recirculated. ☞ Replace EGR actuator, If symptom occurs again after EGR actuator valve cleaning.
Case3	● EGR Actuator valve operation is normal.	● If EGR Actuator valve operation is normal but MAFS current data is abnormal, ☞ Go to 'MAFS inspection' procedure.