2001 TOYOTA AVALON Service Repair Manual

DI-82
- DIAGNOSTICSENGINE
238 Author
: Date
:
2001 AVALON (RM808U)
OK
3 Check that fuel tank cap is correctly installed (See page DI-74, step 3).
NG Correctly install fuel tank cap.
OK
4 Check fuel tank cap (See page EC-6, step 4).
NG Replace fuel tank cap.
OK
5 Check filler neck for damage (See page DI-74, step 5).
NG Replace filler pipe.
OK
6 Check vacuum hoses between vapor pressure sensor and fuel tank, charcoal
canister and VSV for pressure switching valve, and VSV for pressure switching
valve and charcoal canister (See page DI-74, step 6).
NG Repair or connect VSV or sensor connector.
OK
7 Check hose and tube between fuel tank and charcoal canister (See page
DI-74, step 7).

- DIAGNOSTICSENGINE
DI-83
239 Author
: Date
:
2001 AVALON (RM808U)
NG Repair or replace.
OK
8 Check VSV connector for EVAP, VSV connector for CCV, VSV connector for pres-
sure switching valve and vapor pressure sensor connector for looseness and
disconnection.
NG Repair or connect VSV or sensor connector.
OK
9 Check vacuum hoses ((8), (9), (10) and (11) in Fig. 1 in circuit description).
CHECK:
(a) Check that the vacuum hose is connected correctly.
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole, damage and blockage.
NG Repair or replace.
OK
10 Check voltage between terminals VC and E2 of ECM connector (See page
DI-74, step 9).
NG Check and replace ECM (See page IN-30).
OK
11 Check voltage between terminals PTNK and E2 of ECM connectors (See page
DI-74, step 10).
OK Go to step 13.

A00230
VSV is ON
VSV is OFF
DI-84
- DIAGNOSTICSENGINE
240 Author
: Date
:
2001 AVALON (RM808U)
NG
12 Check for open and short in harness and connector between vapor pressure sen-
sor
and ECM (See page IN-30).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
13 Check purge flow.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Select the ACTIVE TEST mode on the TOYOTA hand-
held tester.
(c) Disconnect the vacuum hose for the VSV for the EVAP
from the charcoal canister.
(d) Start the engine.
CHECK:
When the VSV for the EVAP is operated by the TOYOTA hand-
held tester, check whether the disconnected hose applies suc-
tion to your finger.
OK:
VSV is ON:
Disconnected hose applies suction to your finger.
VSV is OFF:
Disconnected hose applies no suction to your finger.
OK Go to step 17.
NG
14 Check vacuum hose between intake manifold and VSV for EVAP, and VSV for
EVAP and charcoal canister.
CHECK:
(a) Check that the vacuum hose is connected correctly.

A10150A10149BE6653
A10281VSV is ONVSV is OFF ON
Air
FAir
E
F E
- DIAGNOSTICSENGINE
DI-85
241 Author
: Date
:
2001 AVALON (RM808U)
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole, damage and blockage.
NG Repair or replace.
OK
15 Check operation of VSV for EVAP (See page SF-65).
OK Go to step 16.
NG
Replace VSV and charcoal canister, and then clean vacuum hoses between throttle body and
VSV for EVAP, and VSV for EVAP and charcoal canister.
16 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for EVAP, and VSV for EVAP and ECM (See page
IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).
17 Check VSV for CCV.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Disconnect the vacuum hose for the VSV for the CCV
from the charcoal canister.
(c) Turn the ignition switch ON and push the TOYOTA hand-
held tester main switch ON.
(d) Select the ACTIVE TEST mode on the TOYOTA hand-
held tester.

DI-86
- DIAGNOSTICSENGINE
242 Author
: Date
:
2001 AVALON (RM808U)
CHECK:
Check the VSV operation when it is operated by the TOYOTA
hand-held tester.
OK:
VSV is ON:
Air does not flow from port E to port F.
VSV is OFF:
Air from port E flows out through port F.
OK Go to step 21.
NG
18 Check vacuum hose between VSV for CCV and charcoal canister.
CHECK:
(a) Check that the vacuum hose is connected correctly.
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole damage, and blockage.
NG Repair or replace.
OK
19 Check operation of VSV for CCV (See page SF-70).
OK Go to step 20.
NG
Replace VSV and charcoal canister, and then
clean vacuum hose between charcoal canis-
ter and VSV for CCV.
20 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for CCV, and VSV for CCV and ECM (See page IN-30).
NG Repair or replace harness or connector.

BE6653A10143A10144A10801VSV is ONVSV is OFF ON
Air
Air
E
FE
F
- DIAGNOSTICSENGINE
DI-87
243 Author
: Date
:
2001 AVALON (RM808U)
OK
Check and replace ECM (See page IN-30).
21 Check VSV for pressure switching valve.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand-
held tester main switch ON.
(c) Select the ACTIVE TEST mode on the TOYOTA hand-
held tester.
CHECK:
Check the VSV operation when it is operated by the TOYOTA
hand-held tester.
OK:
VSV is ON:
Air from port E flows out through port F.
VSV is OFF:
Air does not flow from port E to port F.
OK Go to step 24.
NG
22 Check operation of VSV for pressure switching valve (See page SF-72).
OK Go to step 23.
NG
Replace VSV and charcoal canister, and then clean vacuum hoses between charcoal canister
and VSV for pressure switching valve, and VSV for pressure switching valve and fuel tank.
23 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for pressure switching valve, and VSV for pressure
switching valve and ECM (See page IN-30).

A10620A10574A11937
ON
VSV for pressure
Switching Valve
OFF
VSV for EVAP
1.2 V ON
OFF
E2
PTNK (-) (+)
ON
OFF
VSV for CCV
Measure
Voltage30 sec.
DI-88
- DIAGNOSTICSENGINE
244 Author
: Date
:
2001 AVALON (RM808U)
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).
24 Check fuel tank.
PREPARATION:
(a) Remove the grove compartment (See page SF-82).
(b) Connect the TOYOTA hand-held tester to the DLC3.
(c) Select the ACTIVE TEST mode on the TOYOTA hand-
held tester.
(d) Start the engine.
(e) The VSV for the CCV is ON by the TOYOTA hand-held
tester.
(f) The VSV for the EVAP and the VSV for the pressure
switching valve are ON by the TOYOTA hand-held tester
and hold the VSV for the EVAP until voltage between ter-
minals PTNK and E2 becomes 1.2 V.
CHECK:
Measure the voltage between terminals PTNK and E2 of the
ECM connectors 30 sec. after switching the VSV for the EVAP
and the VSV for the pressure switching valve from ON to OFF.
OK:
Voltage:
When there is no sharp change of the voltage with the
voltage of more or less 1.2 V
NG Replace fuel tank.
OK

A10574 A10621A11938 ON
OFF
ON
OFF
E2
PTNK (-) (+)
ON
OFF VSV for pressure
Switching Valve VSV for EVAP
VSV for CCV
1.2 V Measure
Voltage30 sec.
- DIAGNOSTICSENGINE
DI-89
245 Author
: Date
:
2001 AVALON (RM808U)
25 Check charcoal canister.
PREPARATION:
(a) Remove the grove compartment (See page SF-82).
(b) Connect the TOYOTA hand-held tester to the DLC3.
(c) Select the ACTIVE TEST mode on the TOYOTA hand-
held tester.
(d) Start the engine.
(e) The VSV for the CCV and the VSV for the pressure
switching valve are ON by the TOYOTA hand-held tester.
(f) The VSV for the EVAP is ON by the TOYOTA hand-held
tester and hold the VSV for the EVAP until voltage be-
tween terminals PTNK and E2 becomes 1.2 V.
CHECK:
Measure the voltage between terminals PTNK and E2 of the
ECM connectors 30 sec. after switching the VSV for the EVAP
from ON to OFF.
OK:
Voltage:
When there is no sharp change of the voltage with the
voltage of more or less 1.2 V
NG Replace charcoal canister.
OK
26 Remove charcoal canister and check it (See page EC-6).
NG Replace charcoal canister.
OK
27 Check fuel tank over fill check valve (See page EC-6).
NG Replace fuel tank over fill check valve or fuel
tank.
OK