TOYOTA AVALON 2001 Service Repair Manual

EC01H-03
- EMISSION CONTROLEMISSION CONTROL SYSTEM
EC-1
1095 Author
: Date
:
2001 AVALON (RM808U)
EMISSION CONTROL SYSTEM
PURPOSE
The emission control systems are installed to reduce the amount of CO, HC and NOx exhausted from the
engine ((3) (4) and (5)), to prevent the atmospheric release of blow-by gas-containing HC (1) and evapo-
rated fuel containing HC being released from the fuel tank (2).
The function of each system is shown in these table.
SystemAbbreviationFunction
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Warm Up Three-Way Catalytic Converter
(4) Three-Way Catalytic Converter
(5) Sequential Multiport Fuel injection*PCV
EVAP
WU-TWC
TWC
SFIReduces HC
Reduces evaporated HC
Reduces HC, CO and NOx
Reduces HC, CO and NOx
Injects a precisely timed, optimum amount of fuel for reduced
exhaust emissions
Remark: * For inspection and repair of the SFI system, refer to the SF section of this manual.

EC0BF-02
B08627
Vapor Pressure Sensor
ConnectorVapor Pressure SensorEVAP Line Hose
Vent Line Hose
Air Inlet Line Hose
Purge Line Hose
Air Drain Hose
39.2 (400, 29)
N´m (kgf´cm, ft´lbf) : Specified torqueCharcoal Canister
Charcoal Canister
VSV for Pressure Switching Valve
Fuel Hose
VSV Connector for Pressure
Switching Valve
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC-5
1099 Author
: Date
:
2001 AVALON (RM808U)
EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
COMPONENTS

EC0B4-03
B01082
Gasket
B06544
Vacuum
Gauge
A10838
TOYOTA Hand-Held Tester
DLC3
B06722
Battery EC-6
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1100 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION
1. VISUALLY INSPECT LINES AND CONNECTORS
Visually check for loose connections, sharp bends or damage.
2. VISUALLY INSPECT FUEL TANK FILLER PIPE
Visually check for deformation, cracks or fuel leakage.
3. INSPECT FUEL TANK CAP
Visually check if the cap and/or gasket are deformed or dam-
aged.
If necessary, repair or replace the cap.
4. INSPECT EVAP SYSTEM LINE
(a) Warm up the engine and stop the engine.
Allow the engine to warm up to normal operating tempera-
ture.
(b) Install a vacuum gauge (EVAP control system test equip-
ment vacuum gauge) to the EVAP service port on the
purge line.
(c) TOYOTA Hand-Held Tester:
Forced driving of the VSV for the EVAP.
(1) Connect a TOYOTA hand-held tester to the DLC3.
(2) Start the engine.
(3) Push the TOYOTA hand-held tester main switch
ON.
(4) Use the ACTIVE TEST mode on the TOYOTA
hand-held tester to operate the VSV for the EVAP.
(d) If you have no TOYOTA Hand-Held Tester:
Forced driving of the VSV for the EVAP.
(1) Disconnect the VSV connector for the EVAP.
(2) Connect the positive (+) and negative (-) leads from
the battery to the VSV terminals for the EVAP.
(3) Start the engine.

B06545
B08626
Hose Clipper
Air Drain Hose
B06546
Pressure
Gauge
Pressure
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC-7
1101 Author
: Date
:
2001 AVALON (RM808U)
(e) Check the vacuum at idle.
Vacuum:
Maintain at 0.368 - 19.713 in.Hg (5 - 268 in.Aq) for over
5 seconds
HINT:
If the vacuum does not change, you can conclude that the hose
connecting the VSV to the service port has come loose or is
blocked, or the VSV is malfunctioning.
(f) TOYOTA Hand-Held Tester:
Conclude forced driving of the VSV for the EVAP.
(1) Stop the engine.
(2) Disconnect the TOYOTA hand-held tester from the
DLC3.
(g) If you have no TOYOTA Hand-Held Tester:
Conclude forced driving of the VSV for the EVAP.
(1) Stop the engine.
(2) Disconnect the positive (+) and negative (-) leads
from the battery from the VSV terminals for the
EVAP.
(3) Connect the VSV connector for the EVAP.
(h) Disconnect the vacuum gauge from the EVAP service
port on the purge line.
(i) Connect a pressure gauge to the EVAP service port on
the purge line.
(j) Check the pressure.
(1) Close off the air drain hose at the marked position
of the canister with a hose clipper or similar instru-
ment.
(2) Add the pressure (13.5 - 15.5 in.Aq) from the EVAP
service port.
Pressure:
2 minutes after the pressure is added, the gauge
should be over 7.7 - 8.8 in.Aq.
HINT:
If you can't add pressure, you can conclude that the hose con-
necting the VSV
canister
fuel tank has slipped off or the
VSV is open.

B06547
Fuel Tank Cap
B08623
Air
Disconnect
EVAP Line Hose
B08624Air
Disconnect
Cap
Disconnect
EVAP Line HosePurge Line
Hose
Purge Port
EC-8
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1102 Author
: Date
:
2001 AVALON (RM808U)
(3) Check if the pressure decreases when the fuel tank
cap is removed while adding pressure.
HINT:
If the pressure does not decrease when the filler cap is re-
moved, then you can conclude that the hose connecting the
service port to the fuel tank is blocked, etc.
(k) Disconnect the pressure gauge from the EVAP service
port on the purge line.
5. CHECK AIRTIGHTNESS IN FUEL TANK AND FILLER
PIPE
(a) Disconnect the EVAP line hose from the charcoal canister
side and then pressurize and make the internal pressure
in the fuel tank 4 kPa (41 gf/cm
2, 0.58 psi).
(b) Check that the internal pressure of the fuel tank can be
hold for 1 minute.
(c) Check the connected portions of each hose and pipe.
(d) Check the installed parts on the fuel tank.
If there is no abnormality, replace the fuel tank and filler pipe.
(e) Reconnect the EVAP line hose to the charcoal canister.
6. INSPECT FUEL CUTOFF VALVE AND FILL CHECK
VA LV E
(a) Disconnect the purge line hose and EVAP line hose from
the charcoal canister.
(b) Plug the cap to the air drain hose.
(c) Pressurize 4 kPa (41 gf/cm
2, 0.58 psi) to the purge port
and check that there is ventilation through the EVAP line
hose.
HINT:
In the condition that the fuel fuel is full, as the float value of the
fill check valve is closed and has no ventilation, it is necessary
to check the fuel amount (volume).
(d) Check if there is any struck in the vent line hose and EVAP
line hose.
If there is no stuck in hoses, replace the fuel cutoff valve and fill
check valve.
(e) Reconnect the purge line hose and EVAP line hose to the
charcoal canister.

B08625AirDisconnect
Air Inlet
Line Hose
B01253
Pinch
Push
AA
Pinch
B08620
B08621
Purge Port
Vent Port
Cap EVAP Port
Air Drain Port
Air
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC-9
1103 Author
: Date
:
2001 AVALON (RM808U)
7. CHECK AIR INLET LINE
(a) Disconnect the air inlet line hose from the charcoal canis-
ter.
(b) Check that there is ventilation in the air inlet line.
(c) Reconnect the air inlet line hose to the charcoal canister.
8. REMOVE CHARCOAL CANISTER ASSEMBLY
(a) Disconnect the VSV connector for the pressure switching
valve.
(b) Disconnect the vapor pressure sensor connector.
(c) Disconnect the fuel hose from the vapor pressure sensor.
(d) Disconnect the purge line hose, EVAP line hose and air
inlet line hose from the charcoal canister.
(e) Disconnect the vent line hose from the charcoal canister.
(1) Push the connector deep inside.
(2) Pinch portion A.
(3) Pull out the connector.
(f) Remove the 2 charcoal canister mounting bolts.
(g) Remove the vapor pressure sensor mounting bolt.
(h) Remove the charcoal canister assembly.
9. INSPECT CHARCOAL CANISTER
(a) Visually check the charcoal canister for cracks or dam-
age.
(b) Inspect the charcoal canister operation.
(1) Plug the vent port with the cap.
(2) While holding the purge port closed, blow air (1.76
kPa, 18 gf/cm
2, 0.26 psi) into the EVAP port and
check that air flows from the air drain port.

B08622
Air
Purge Port
EVAP
Port Air Drain PortAir Inlet Port
B08673
Vacuum
Purge PortAir Inlet Port
B08670Vacuum
Purge Port
EVAP
Port
Air Inlet Port
EC-10
- EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
1104 Author
: Date
:
2001 AVALON (RM808U)
(3) While holding the purge port and the air drain port
closed, blow air (1.76 kPa, 18 gf/cm
2, 0.26 psi) into
the EVAP port and check that air does not flow from
the air inlet port.
(4) Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg)
to the purge port, check that the vacuum does not
decrease when the air inlet port is closed, and
check that the vacuum decreases when the air inlet
port is released.
(5) While holding the air inlet port closed, apply vacuum
(3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port
and check that air flows into the purge port.
If operation is not as specified, replace the charcoal canister.
(6) Remove the hose and cap from vent port.
10. INSPECT VSV FOR EVAP (See page SF-65)
11. INSPECT VSV FOR CANISTER CLOSED VALVE (CCV)
(See page SF-70)
12. INSPECT VSV FOR PRESSURE SWITCHING VALVE
(See page SF-72)
13. INSPECT VAPOR PRESSURE SENSOR
(See page SF-75)
14. REINSTALL CHARCOAL CANISTER ASSEMBLY

S05053
PCV Valve
EC04N-02
P02006Cylinder Head sideClean Hose
P02477
Intake Manifold
Side
P12931
EC-4- EMISSION CONTROLPOSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM
1098 Author
: Date
:
2001 AVALON (RM808U)
POSITIVE CRANKCASE
VENTILATION (PCV) SYSTEM
INSPECTION
1. INSPECT PCV VALVE
(a) Remove the PCV valve.
(b) Install clean hose to the PCV valve.
(c) Inspect the PCV valve operation.
(1) Blow air into the cylinder head side, and check that
air passes through easily.
CAUTION:
Do not suck air through the valve.
Petroleum substances inside the valve are harmful.
(2) Blow air into the intake manifold side, and check
that air passes through with difficulty.
If operation is not as specified, replace the PCV valve.
(d) Remove clean hose from the PCV valve.
(e) Reinstall the PCV valve.
2. VISUALLY INSPECT HOSES, CONNECTIONS AND
GASKETS
Check for cracks, leaks or damage.

EC01J-03
B08913
Vapor
Pressure
Sensor
A/F Sensor
(Bank 2 Sensor 1)A/F Sensor
(Bank 1 Sensor 1)
TWCVSV for EVAP
Fuel Tank
Charcoal
Canister
WU-TWCHeated Oxygen Sensor
(Bank 1 Sensor 2)
WU-TWC
EVAP Service Port
Purge Line
Air Inlet Line Air Drain
HoseEVAP Line
Vent Line
VSV for Canister
Closed Valve (CCV) VSV for Pressure
Switching Valve
Air Cleaner
- EMISSION CONTROLPARTS LAYOUT AND SCHEMATIC DRAWING
EC-3
1097 Author
: Date
:
2001 AVALON (RM808U)
DRAWING

EC04L-03
B07254
Vent LineCharcoal Canister
Fuel Tank
EVAP Line
Air Drain Hose
Filler Pipe
Air Inlet Line
Purge Line
Cut Off Valve
Fill Check Valve
VSV for EVAPVacuum Surge TankEVAP Service Port
Vapor Pressure Sensor
Fuel Tank Cap
VSV for Pressure Switching Valve PCV Valve
VSV for Canister Closed Valve (CCV)
EC-2
- EMISSION CONTROLPARTS LAYOUT AND SCHEMATIC DRAWING
1096 Author
: Date
:
2001 AVALON (RM808U)
PARTS LAYOUT AND SCHEMATIC DRAWING
LOCATION