2000 TOYOTA CAMRY check engine

A06551
VSV for
EVAP
Charcoal Canister
Fuel Tank ECM
Vapor Pressure
Sensor
VSV for Vapor
Pressure Sensor
Fuel Tank Over
Fill Check Valve
DI±142
± DIAGNOSTICSENGINE (5S±FE)
377 Author: Date:
DTC P0450 Evaporative Emission Control System
Pressure Sensor Malfunction
DTC P0451 Evaporative Emission Control System
Pressure Sensor Range/Performance
CIRCUIT DESCRIPTION
The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evap-
orative 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 is recorded by the ECM when the vapor pressure sensor malfunction.
DI1K0±04

± DIAGNOSTICSENGINE (5S±FE)
DI±143
378 Author: Date:
DTC No.DTC Detecting ConditionTrouble Area
P0450
10 seconds or more after engine starting codition (a) or (b)
continues for 7 seconds or more:
(2 trip detection logic)
(a) vapor pressure sensor value < ±4 kpa (±30 mmHg,
±1.0 in.Hg)
(b) Vapor pressure sensor value
2.1 kpa (±15 mmHg,
0.4 in.Hg)

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

ECM
F l t k fill h k l k d d d
P0451
Vapor pressure sensor output extremely changes under condi-
tions of (a), (b) and (c):
(2 trip detection logic)
(a) Vehicle speed: 0 km/h (0 mph)
(b) Engine speed: idling
(c) VSV for vapor pressure sensor is ON
Fuel tank over fill check valve cracked or damaged.
WIRING DIAGRAM
Refer to DTC P0440 (Evaporative Emission Control System Malfunction) on page DI±122.
INSPECTION PROCEDURE
HINT:

If DTC P0441 (Evaporative Emission Control System Incorrect Purge Flow), P0446 (Evaporative
Emission Control System Vent Control Malfunction), P0450 (Evaporative Emission Control System
Pressure Sensor Malfunction) or P0451 is output after DTC P0440 (Evaporative Emission Control Sys-
tem Malfunction), first troubleshoot DTC P0441, P0446, P0450 or P0451. If no malfunction is detected,
troubleshoot DTC P0440 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 warmed up or not, the air±fuel
ratio 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±122, step 9).
NG Check and replace ECM (See page IN±31).
OK

DI±144
± DIAGNOSTICSENGINE (5S±FE)
379 Author: Date:
2 Check voltage between terminals PTNK and E2 of ECM connector
(See page DI±122, step 10 ).
OK Check and replace ECM (See page IN±31).
NG
3 Check for open and short in harness and connector between the vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.

DI±146
± DIAGNOSTICSENGINE (5S±FE)
381 Author: Date:
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 warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedmeter 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 combination
meter troubleshooting (See page BE±2).
OK

A03021
A03425
ON
SP1
(+)
SP1
(+)
w/o Immobiliser
w/ Immobiliser
AT7809
4.5 ~ 5.5 V
0
Turn the wheel
± DIAGNOSTICSENGINE (5S±FE)
DI±147
382 Author: Date:
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Shift the shift lever to neutral.
(c) Jack up one of the front wheels.
(d) Turn the ignition switch ON.
CHECK:
Measure voltage between terminal SPD of ECM connector and
body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector
between combination meter and ECM.
OK
Check and replace ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±149
384 Author: Date:
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 warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check idle speed.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all the accessories.
(c) Switch off the air conditioning.
(d) Shift the transmission into N or neutral position.
(e) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3 on the vehicle.
(f) Using SST, connect terminals TE1 and E1 of the DLC1.
CHECK:
Check the difference of engine speed between the ones less than 5 sec. and more than 5 sec. after connect-
ing terminals TE1 and E1 of the DLC1.
OK:
Difference of engine speed: More than 100 rpm
OK Go to step 6.
NG

A00416
A03022A03426
E9 Connector
RSC(+) RSO(+)
E9 Connector
RSO(+)
RSC(+) w/o Immobiliser
w/ Immobiliser
DI±150
± DIAGNOSTICSENGINE (5S±FE)
385 Author: Date:
2 Check voltage between terminals RSO, RSC of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Disconnect the E9 connector of the ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals RSO, RSC of the ECM
connector and body ground,
OK:
Voltage: 9 ~ 14 V
OK Go to step 4.
NG
3 Check IAC valve (See page SF±35).
NG Replace IAC valve.
OK
Check for open and short in harness and connector between engine room J/B No.2 and IAC valve,
and IAC valve and ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±151
386 Author: Date:
4 Check operation of IAC valve (See page SF±35).
NG Repair or replace IAC valve.
OK
5 Check blockage of IAC valve and passage to bypass throttle valve.
NG Repair or replace IAC valve.
OK
Check and replace ECM (See page IN±31).
6 Check for A/C signal circuit (See page AC±84).
NG Repair or replace.
OK
Check air induction system
(See page SF±1).