TOYOTA AVALON 2001 Service Repair Manual
Page 971 of 1897
DI-92
- DIAGNOSTICSENGINE
248 Author: Date:
2001 AVALON (RM808U)
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.
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.
Page 972 of 1897
A02028
ON
EVP1
Air
Air
F
F E
E ONOFF
VSV is ON
VSV is OFF
- DIAGNOSTICSENGINE
DI-93
249 Author: Date:
2001 AVALON (RM808U)
13 Check VSV for EVAP.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Check the VSV function.
(1) Connect between terminal EVP1 of the ECM con-
nector and body ground (ON).
(2) Disconnect between terminal EVP1 of the ECM
connector and body ground (OFF).
OK:
(1) VSV is ON:
Air from port E flows out through port F.
(2) VSV is OFF:
Air does not flow from port E to port F.
OK Go to step 16.
NG
14 Check operation of VSV for EVAP (See page SF-65).
OK Go to step 15.
NG
Replace VSV and clean vacuum hoses between throttle body and VSV for EVAP, and VSV for
EVAP and charcoal canister, and then check charcoal canister.
15 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.
Page 973 of 1897
BE6653
A10281A10310
A10951
VSV is ON
VSV is OFF ON
CCV
OFF ON
Air
E Air
E
FF
DI-94
- DIAGNOSTICSENGINE
250 Author: Date:
2001 AVALON (RM808U)
OK
Check and replace ECM (See page IN-30).
16 Check VSV for CCV.
PREPARATION:
(a) Remove the grove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Check the VSV function.
(1) Connect between terminal CCV of the ECM con-
nector and body ground (ON).
(2) Disconnect between terminal CCV of the ECM con-
nector and body ground (OFF).
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 19.
NG
17 Check operation of VSV for CCV (See page SF-70).
OK Go to step 18.
NG
Replace VSV and charcoal canister, and then
clean vacuum hose between charcoal canis-
ter and VSV for CCV.
Page 974 of 1897
BE6653
A10278A10604A10952
VSV is ONVSV is OFF ON
TBP
OFFON
Air
E Air
E
FF
- DIAGNOSTICSENGINE
DI-95
251 Author: Date:
2001 AVALON (RM808U)
18 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.
OK
Check and replace ECM (See page IN-30).
19 Check VSV for pressure switching valve.
PREPARATION:
(a) Remove the grove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Check the VSV function.
(1) Connect between terminal TBP of the ECM connec-
tor and body ground (ON).
(2) Disconnect between terminal TBP of the ECM con-
nector and body ground (OFF).
OK:
(1) VSV is ON:
Air from port E flows out through port F.
(2) VSV is OFF:
Air does not from flow port E to port F.
OK Go to step 22.
NG
20 Check operation of VSV for pressure switching valve (See page SF-72).
OK Go to step 21.
Page 975 of 1897
DI-96
- DIAGNOSTICSENGINE
252 Author: Date:
2001 AVALON (RM808U)
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.
21 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).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).
22 Check the fuel tank over fill check valve (See page EC-6).
NG Replace fuel tank over fill check valve or fuel
tank.
OK
Check and replace charcoal canister (See
page IN-30).
Page 976 of 1897
A10145
ECM
Fuel Tank Charcoal Canister VSV for
EVAPFuel Tank Over
Fill Check Valve
Vapor Pressure Sensor
VSV for
CCVVSV for
Pressure
Switching Valve
- DIAGNOSTICSENGINE
DI-97
253 Author: Date:
2001 AVALON (RM808U)
DTC P0450 Evaporative Emission Control System Pres-
sure Sensor Malfunction
DTC P0451 Evaporative Emission Control System Pres-
sure Sensor Range/Performance
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 P0450 or P0451 is recorded by the ECM when the vapor pressure sensor malfunction.
DTC No.DTC Detecting ConditionTrouble Area
P0450
10 seconds or less after engine starting condition vapor pres-
sure sensor fixed value continues for fixed value or more: (2
trip detection logic)
P0451
Vapor pressure sensor output extremely changes under condi-
tions of (a) and (b): (2 trip detection logic)
(a) Vehicle speed: 0 km/h (0mph), Engine speed: Idling and
VSV for pressure switching valve is OFF
(b) vavor pressure sensor value opening pressure valve of
charcoal canisterOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM
DI081-04
Page 977 of 1897
DI-98
- DIAGNOSTICSENGINE
254 Author: Date:
2001 AVALON (RM808U)
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 trouble shoot 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
VSV for EVAP, charcoal canister and vapor pressure sensor.
1 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
2 Check voltage between terminals PTNK and E2 of ECM connectors (See page
DI-74, step 10).
OK Check and replace ECM (See page IN-30).
NG
3 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.
Page 978 of 1897
A00022
4-Pulse
Engine
ECM
Multi Display From
Speed Sensor4-Pulse
ABS Actuator
& ECU
A11086
Multi Display
18
M3 E73F V-W V-WECM
SPD5 V
122
3C 1J/B No.3
- DIAGNOSTICSENGINE
DI-99
255 Author: Date:
2001 AVALON (RM808U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This sensor is mounted in the combination meter. It contains a magnet which is rotated by the speedometer
cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedometer.
It is then transmitted to the Engine ECM. The Engine ECM determines the vehicle speed based on the fre-
quency of these pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
No vehicle speed sensor signal to Engine & ECT ECU underCombination meter
P0500/61
No vehicle speed sensor signal to Engine & ECT ECU under
th f ll i diti (2 t i d t ti l i )
Combination meter
Ohtid iitP0500/61the following conditions: (2 trip detection logic)Open or short in speed sensor circuitg( g)
Vehicle is being drivenECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
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.
DI082-09
Page 979 of 1897
A02030
E7 Connector
SPD
A02029
E7 ConnectorON
SPD(-) (+)
DI-100
- DIAGNOSTICSENGINE
256 Author: Date:
2001 AVALON (RM808U)
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit (See page BE-43).
OK
2 Check for short in harness and connector between terminal SPD of ECM and
body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF-83).
(b) Disconnect the E7 connector from the ECM.
CHECK:
Check the continuity between terminal SPD of the ECM con-
nector and body ground.
OK:
No continuity (1 MW or higher)
NG Repair or replace harness or connector.
OK
3 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF-83).
(b) Disconnect the E7 connector from the ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal SPD of the ECM con-
nector and body ground.
OK:
Voltage: 9 - 14 V
NG Check for open in harness and connector be-
tween J/B No.3 and ECM (See page IN-30).
Page 980 of 1897
- DIAGNOSTICSENGINE
DI-101
257 Author: Date:
2001 AVALON (RM808U)
OK
4 Check for open in harness and connector between J/B No.3 and combination
meter (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).