Toyota 1 MZ–FE Manual page 207

Engine
Coolant
VSV
Temp.
Below ON
55°C OPENS passage
(131°F) to atmosphere
Above
OFF
60°C
CLOSED passage
(140°F)
to atmosphere
* Pressure increase Modulator closes
EGR valve closes
** When the throttle valve is positioned above port R, 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.
1MZ–FE ENGINE
Throttle Valve Pressure in the EGR
Position
Valve Pressure Chamber
Positioned below
port E
(1)
LOW
Positioned between
port E and port R
(2)
HIGH
(3)
Positioned above
port R HIGH
EGR valve opens
Modulator opens
EGR SYSTEM INSPECTION
1. CHECK AND CLEAN FILTER IN EGR VACUUM
MODULATOR
(a) Remove the cap and filter.
(b) Check the filter for contamination or damage.
(c) Using compressed air, clean the filter.
(d) Reinstall the filter and cap.
HINT: Install the filter with the coarser surface facing
out to the atmospheric side.
2. INSTALL VACUUM GAUGE
Using a 3–way connector, connect a vacuum gauge
to the hose between the EGR valve and EGR VSV.
3. INSPECT SEATING OF EGR VALVE
Check that the engine starts and runs at idle.
4. CONNECT TERMINALS TE1 AND E1
Using SST, connect terminal TE1 and E1 of the data
link connector 1.
SST 09843–18020
– EMISSION CONTROL SYSTEMS
EG R Vacuum
Modulator
OPENS passage
*Pressure con–
to atmosphere
stantly alternating
between low and
CLOSES passage
high
to atmosphere'
CLOSES passage,
to atmosphere
Pressure drops
EG2–207
Exhaust
EG R
Gas
Valve
Not
CLOSED
recirculated
Not
CLOSED
recirculated
Not
CLOSED
recirculated
Recirculated
OPEN
Recirculated
OPEN
(increase)