Page 953 of 1897
A10140
ECM
VSV
for EVAP
Charcoal Canister
Fuel Tank Fig. 1
(2)
(3) (4) (6)
(8)
(9)(1)
(5)
Fuel Tank Over
Fill Check Valve
(7)Vapor Pressure
Sensor
VSV for
CCVVSV for
Pressure
Switching
Valve
(10)
(11) DI-74
- DIAGNOSTICSENGINE
230 Author: Date:
2001 AVALON (RM808U)
DTC P0440 Evaporative Emission Control System Mal-
function
DTC P0442 Evaporative Emission Control System Leak
Detected (Small Leak)
CIRCUIT DESCRIPTION
The vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for pressure switching valve are
used to detect abnormalities in the evaporative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTC P0440 or P0442 is recorded by the ECM when evaporative emissions leak from the components within
the dotted line in Fig. 1 below, or when the vapor pressure sensor malfunctions.
DTC No.DTC Detecting ConditionTrouble Area
P0440
P0442After cold starting and when generating certain swift pressure
value in fuel tank enabling not to hold that value (2 trip detec-
tion logic)
Hose or tube cracked, hole, damaged or loose seal ((3) in
Fig. 1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or discon-
nected ((1) or (2) in Fig. 1)
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Fuel tank over fill check valve cracked or damaged
ECM
DI6T6-01
Page 954 of 1897
A11666
ECM
Vapor Pressure Sensor
2B6
P-B
VSV for EVAP
B-R
2
15 V
VC
PTNK
E1
E2
EVP1
E01
E01
TBP
3
2
Engine Room J/B
B-W
W-B
P
1
WE5
E82
17
18
7
3
E7
EFI Relay
PL-R
ID1 II215 4
5
E5
ID1 9
6 2G
4 2
53
2
1 EFI
No.1
From
Battery
20
G
VSV for Pressure
Switching ValveCCV
2
110
318
1
VSV for CCV
14
E01 L-R L-R
W WID1
ID1 II2
E5
E8 B-W
2B
2B 2FEFI
No.2
4
EDID1II1 G
B-W B-W
2
P-B
L-OFrom
Terminal
MREL of
ECM
B
B-W
- DIAGNOSTICSENGINE
DI-75
231 Author: Date:
2001 AVALON (RM808U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 or P0442, first troubleshoot DTC
P0441, P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 or P0442 next.
Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tight-
ened it. Also ask the customer whether the fuel tank cap was loose when refuelling. If the fuel tank cap
was loose, it was the cause of the DTC. If the fuel tank cap was not loose or if the customer was not
sure if it was loose, troubleshoot according to the following procedure.
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
vapor pressure sensor.
Page 956 of 1897
- DIAGNOSTICSENGINE
DI-77
233 Author: Date:
2001 AVALON (RM808U)
5 Check filler neck for damage.
PREPARATION:
Remove the fuel tank cap.
CHECK:
Visually inspect the filler neck for damage.
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.
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 and damage.
NG Repair or replace.
OK
7 Check hose and tube between fuel tank and charcoal canister.
CHECK:
(a) Check for proper connection of the fuel tank and fuel evap pipe (See page EC-6), fuel evap pipe and
fuel tube under the floor, fuel tube under the floor and charcoal canister.
(b) Check the hose and tube for cracks, hole and damage.
NG Repair or replace.
OK
8 Check charcoal canister for cracks, hole and damage (See page EC-6).
NG Replace charcoal canister.
Page 958 of 1897
- DIAGNOSTICSENGINE
DI-79
235 Author: Date:
2001 AVALON (RM808U)
11 Check for open and short in harness and connector between vapor pressure
sensor and ECM (See page IN-30).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
12 Check fuel tank and fuel tank over fill check valve for cracks and damage.
NG Replace fuel tank or fuel tank over fill check
valve.
OK
It is likely that vehicle user did not properly close fuel tank cap. Please explain to customer how
to properly install fuel tank cap.
Page 959 of 1897
A10142
ECM
Fuel Tank Charcoal Canister VSV for
EVAP
(1) Fig. 1
(2)
(3) (4)
(5)(6)
(7)
Fuel Tank Over
Fill Check Valve
(10)
(9)
Vapor Pressure
Sensor
VSV for
CCVVSV for
Pressure
Switching Valve
(8)
(11) DI-80
- DIAGNOSTICSENGINE
236 Author: Date:
2001 AVALON (RM808U)
DTC P0441 Evaporative Emission Control System Incor-
rect Purge Flow
DTC P0446 Evaporative Emission Control System Vent
Control Malfunction
CIRCUIT DESCRIPTION
The vapor pressure sensor, VSV for canister closed valve (CCV), VSV for pressure switching valve are used
to detect abnormalities in the evaporative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components
within the dotted line in Fig. 1 below, or when there is a malfunction in either the VSV for EVAP, the VSV for
pressure switching valve, or in the vapor pressure sensor itself.
DI6T7-01
Page 960 of 1897
- DIAGNOSTICSENGINE
DI-81
237 Author: Date:
2001 AVALON (RM808U)DTC No.
DTC Detecting ConditionTrouble Area
P0441
Pressure in charcoal canister and fuel tank does not drop dur-
ing purge control (2 trip detection logic)Vacuum hose cracks, holed blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8), (9), (10) and (11) in
Fig 1)P0441
During purge cut-off, negative pressure incomming in the char-
coal canister and fuel tank will not stop. (2 trip detection logic)
Fig. 1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Open or short in vaporpressure sensorcircuit
When VSV for pressure switching valve is ON, ECM judges
that there is no continuity between vapor pressure sensor, fuel
tank and charcoal canister (2 trip detection logic)
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
O h t i VSV i it f CCV
P0446
When VSV for pressure switching valve is turned OFF, pres-
sure in fuel tank is maintained at atmospheric pressure (2 trip
detection logic)
Open or short in VSV circuit for CCV
VSV for CCV
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
When VSV for CCV is ON, pressure in charcoal canister and
fuel tank is maintained at atmospheric pressure (2 trip detec-
tion logic)
g
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked damaged
ECM
WIRING DIAGRAM
Refer to DTC P0440 or P0442 on page DI-74.
INSPECTION PROCEDURE
HINT:
If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 or P0442,first troubleshoot DTC
P0441, P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 or P0442 next.
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
vapor pressure sensor.
TOYOTA hand-held tester:
1 Check whether hose close to fuel tank have been modified, and check whether
there are signs of any accident near fuel tank or charcoal canister (See page
DI-74, step 1).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts (See page DI-74, step 2).
NG Replace to TOYOTA genuine parts.
Page 961 of 1897
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).
Page 966 of 1897
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).
