Toyota 22R-E - Exhaust Gas Recirculation (EGR) System

Remarks: *Pressure increases → Modulator closes → .EGR valve opens → Pressure drops
EGR Valve closes ← Modulator opens
** When the throttle valve is positioned above the R port, the EGR vacuum modulator will close the atmosphere passage
and open the EGR valve to increase the EGR gas, even if the exhaust pressure is insufficiently low.
To reduce NOx emissions, part of the exhaust gases are recirculated through the EGR valve to the intake manifold to lower the
maximum combustion temperature.
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
*Pressure constantly
alternating
between low and
high
Positioned between
EGR port and R
port
Pressure in the EGR
Valve Pressure Chamber
CLOSES passage to
atmosphere
CLOSES passage to
atmosphere
OPENS passage to
atmosphere
Throttle Valve
Opening Angle
Positioned below
EGR port
Positioned above
R port
Engine
Coolant Temp.
EGR Vacuum
Modulator
Recirculated
(increase)
Below 48C
(118F)
Above 52C
(126F)
Not
recirculated
Note
Recirculated
Exhaust Gas
EG R
Valve
(3)
HIGH
(2)
HIGH
CLOSED
CLOSED
(1)
LOW
CLOSED
CLOSED
OPEN
OPEN
OPEN
VSV
Note
Recirculated
Recirculated
–ENGINE EMISSION CONTROL SYSTEMS
EG2–148