WML 213
WML 213
WML 213
1. SPECIFICATION
Item
Motor
E-EGR valve
Valve
E-EGR cooler
Solenoid valve
Specification
EGR response time
50 ms
Driven by
DC motor
120 kg/h
Cooling capacity
8.3 kW or more
Wavy fin
Cooler type
U-shaped
Drivien by
Vacuum
(Solenoid valve)
13-3
13-4
1. SYSTEM DESCRIPTION
1) Overview
The EGR (Electric-Exhaust Gas Recirculation) valve reduces the NOx emission level by recirculating
some of the exhaust gas to the intake system.
To meet Euro-V regulation, the capacity and response rate of E-EGR valve in D20DTR engine have been
greatly improved. The EGR cooler with high capacity reduces the Nox, and the bypass valve reduces the
CO and HC due to EGR gas before warming up.
Also, the engine ECU adjusts the E-EGR opening by using the air mass signal through HFM sensor. If
the exhaust gas gets into the intake manifold when the EGR valve is open, the amount of fresh air
through HFM sensor should be decresed.
Benefits of E-EGR valve
-
1793-00
13-5
EGR cooler
E-EGR valve
EGR bypass
EGR pipe
13-6
2. OPERATING PROCESS
1) Schematic Diagram
1793-00
2) Input/Output Devices
13-7
13-8
3) Control Logic
The EGR system controls the EGR amount based on the map values shown below:
Main map value: Intake air volume
Auxiliary map value:
- Compensation by the coolant temperature
- Compensation by the atmospheric pressure: Altitude compensation
- Compensation by the boost pressure deviation (the difference between the requested value and the
measured value of boost pressure)
- Compensation by the engine load: During sudden acceleration
- Compensation by the intake air temperature
The engine ECU calculates the EGR amount by adding main map value (intake air volume) and auxiliary
map value and directly drives the solenoid valve in the E-EGR to regulate the opening extent of the EGR
valve and sends the feedback to the potentiometer.