2001 TOYOTA PRIUS Service Repair Manual

B11801
B12240
B11803
B11804
B11805
Port APort C
Port B
EC±10
± EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
2001 PRIUS (RM778U)
(b) Disconnect the air inlet hose from the air cleaner case.
(c) Blow air into the air inlet line hose.
(d) Check that the air flows from the air inlet line hose.
(e) Visually check the air inlet line hoses and pipes.
(f) Check each connection of hoses and pipes.
If there is abnormality, replace the air inlet line hose and pipe.
8. REMOVE CHARCOAL CANISTER ASSEMBLY
(a) Remove the fuel tank (See page SF±17)
(b) Disconnect the 3 hoses from the charcoal canister.
(c) Remove the 2 bolts and charcoal canister from the fuel
tank.
(d) Remove the 2 bolts and VSV for purge flow switching from
the charcoal canister.
9. INSPECT CHARCOAL CANISTER
(a) Visually check the charcoal canister for cracks or dam-
age.
(b) While holding port C closed, using low pressure com-
pressed air (4.9 kPa (50 gf/cm
2, 0.71 psi), blow into port
A and check that air flows without resistance from the port
B.

B11806
Port APort C
Port B
B11807
B11808
B11809
B11810
Port A
Port B
± EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
EC±11
2001 PRIUS (RM778U)
(c) Using low pressure compressed air (4.9 kPa (50 gf/cm2,
0.71 psi), blow into port A and check that air flows without
resistance from the other ports.
If a problem is found, replace the charcoal canister.
10. REINSTALL CHARCOAL CANISTER ASSEMBLY
11. REMOVE TRAP FILTER AND FRESH AIR VALVE
(a) Remove the fuel tank (See page SF±17).
(b) Disconnect the air inlet hoses from the VSV for canister
closed valve.
(c) Disconnect the connector from the fresh air valve.
(d) Remove the bolt and disconnect the air opening valve
from the VSV for canister closed valve.
(e) Remove the 2 bolts and VSV for canister closed valve
with the trap filter.
(f) Remove the 2 bolts and trap filter from the VSV for canis-
ter closed valve.
12. INSPECT TRAP FILTER
(a) Visually check the trap filter for cracks or damage.
(b) Inspect the trap filter operation.
Blow air into port A, check that the air flows from port B.
If a problem is found, replace the trap filter.

B11811
Port APort C
Port B
EC±12
± EMISSION CONTROLEVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM
2001 PRIUS (RM778U)
13. INSPECT FRESH AIR VALVE
(a) Visually check the fresh air valve for cracks or damage.
(b) Inspect the fresh air valve operation.
Blow air into port A, check that the air flows from port B
and C.
If a problem is found, replace the fresh air valve.
14. REINSTALL TRAP FILTER AND FRESH AIR VALVE

EC0HW±01
F12396
TOYOTA
Hand±held Tester
DLC3
B11812
B11813
± EMISSION CONTROLTHREE±WAY CATALYTIC CONVERTER (TWC)
SYSTEMEC±13
1213 Author: Date:
2001 PRIUS (RM778U)
THREE±WAY CATALYTIC
CONVERTER (TWC) SYSTEM
INSPECTION
1. CHECK TWC FOR DENTS OR DAMAGE
If any port of the heat insulator is damaged to the extent that it
contacts the three±way catalytic converter, repair or replace it.
2. CHECK EXHAUST PIPE CONNECTIONS FOR LOOSE-
NESS OR DAMAGE
3. CHECK EXHAUST PIPE CLAMPS FOR WEAKNESS,
CRACKS OR DAMAGE
4. CHECK HEAT INSULATOR FOR DAMAGE
5. CHECK FOR ADEQUATE CLEARANCE BETWEEN
EXHAUST SYSTEM AND HEAT INSULATOR ON THE
BODY
6. INSPECT HC ABSORBER AND CATALYST SYSTEM
(a) Warm up the engine.
(b) TOYOTA hand±held tester:
Forced driving of the VSV for the HC absorber and cata-
lyst system.
(1) Connect a TOYOTA hand±held tester to the DLC3.
(2) Start the engine.
(3) Push the TOYOTA hand±held tester mode on the
TOYOTA hand±held tester to operate the VSV for
the HC absorber and catalyst system.
(c) If you have no TOYOTA hand±held tester:
Forced driving of the VSV for the TOYOTA HC absorption
catalyst system.
(1) Disconnect the VSV connector for the TOYOTA HC
absorption catalyst system.
(2) Connect the positive (+) and negative (±) leads from
the battery to the VSV.
(3) Start the engine.
(d) Check that the rod of the actuator is pulled and the valve
is operating.
If not in operation, check the vacuum hose line or VSV, actuator.

B11814
B11831
EC±14± EMISSION CONTROLTHREE±WAY CATALYTIC CONVERTER (TWC)
SYSTEM
1214 Author: Date:
2001 PRIUS (RM778U)
7. INSPECT ACTUATOR
(a) Remove the front exhaust pipe.
(b) Remove the actuator from the front exhaust pipe.
(c) Connect the MITYVAC (hand±held vacuum pump) to the
actuator port.
(d) Apply vacuum (more than 33.3 kPa, 250 mmHg, 9.83
in.Hg), make sure that the rod is retracted.
If the not, replace the actuator.
(e) Disconnect the MITYVAC (hand±held vacuum pump)
from the actuator port.
8. INSPECT VALVE OPERATION
(a) Turn the valve stay by hand and ensure that it can turn.
If the not, replace the front exhaust pipe.
(b) Install the actuator to the front exhaust pipe.
(c) Install the front exhaust pipe.