TOYOTA CAMRY 1999 Service Repair Manual

A06550
ECM
(1)Vapor Pressure
Sensor
VSV for Vapor
Pressure Sensor
(2)
(3) (4)
(5) VSV for
EVAP
Charcoal Canister Fuel Tank fig.1
(6)
(7)
(8)
(9) Fuel Tank Over
Fill Check Valve
± DIAGNOSTICSENGINE (5S±FE)
DI±129
364 Author: Date:
DTC P0441 Evaporative Emission Control System
Incorrect Purge Flow
DTC P0446 Evaporative Emission Control System Vent
Control Malfunction
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.
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
vapor pressure sensor, or in the vapor pressure sensor itself.
DI019±10

DI±130
± DIAGNOSTICSENGINE (5S±FE)
365 Author: Date:
DTC No.DTC Detecting ConditionTrouble Area
P0441
Pressure in the charcoal canister does not drop during purge
control
(2 trip detection logic)
P0441During purge cut±off, pressure in charcoal canister is very low
compared with atmospheric pressure
(2 trip detection logic)

Open or short in VSV circuit for vapor pressure sensor

VSV for vapor pressure sensor
When VSV for vapor pressure sensor is OFF, ECM judges that
there is no continuity between vapor pressure sensor 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

Vacuum hose cracks hole blocked damaged or
P0446
When VSV for vapor pressure sensor is ON, ECM judges that
there is no continuity between vapor pressure sensor and fuel
tank
(2 trip detection logic)
Vacuum hose cracks, hole, blocked, damaged or
disconnected ((1), (4), (5) holed (6) and (7) in fig. 1)

Charcoal canister cracked, holed or damaged

Fuel tank over fill check valve cracked or damaged
After purge cut off operates, pressure in charcoal canister is
maintained at atmospheric pressure
(2 trip detection logic)
WIRING DIAGRAM
Refer to DTC P0440 (Evaporative Emission Control System Malfunction) on page DI±122.
INSPECTION PROCEDURE
TOYOTA hand±held tester:
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.

± DIAGNOSTICSENGINE (5S±FE)
DI±131
366 Author: Date:
1 Check VSV connector for EVAP, VSV connector for vapor pressure sensor and
vapor pressure sensor connector for looseness and disconnection.
NG Repair or connect VSV or sensor connector.
OK
2 Check vacuum hoses (1), (4), (5), (6), (7), (8) and (9) on page DI±122).
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
3 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
4 Check voltage between terminals PTNK and E2 of ECM connector
(See page DI±122, step 10).
OK Go to step 6.
NG

A03278A03279A03456
VSV is ON
VSV is OFFTo
Suction
No SuctionThrottle
Body
To
Throttle
Body
DI±132
± DIAGNOSTICSENGINE (5S±FE)
367 Author: Date:
5 Check for open and short in harness and connector between vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.
6 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 EVAP from
the charcoal canister.
(d) Start the engine.
CHECK:
When the VSV for 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 10.
NG

± DIAGNOSTICSENGINE (5S±FE)
DI±133
368 Author: Date:
7 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.
(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
8 Check operation of VSV for EVAP (See page SF±45).
OK Go to step 9.
NG
Replace VSV, charcoal canister and then clean the vacuum hose between throttle body and VSV
for EVAP, and VSV for EVAP and charcoal canister.
9 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±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).

A00472
ON
FE
G
FE
G
VSV is ON
VSV is OFF
DI±134
± DIAGNOSTICSENGINE (5S±FE)
369 Author: Date:
10 Check the VSV for vapor pressure sensor.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool
or 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 TOYOTA
hand±held tester.
OK:
(1) VSV is ON:
Air from port E is flowing out through port F.
(2) VSV is OFF:
Air from port E is flowing out through port G.
OK Go to step 13.
NG
11 Check operation of VSV for vapor pressure sensor (See page SF±47).
OK Gp to step 12.
NG
Replace VSV charcoal canister, and then clean the vacuum hoses between charcoal canister and
VSV for vapor pressure sensor, and VSV for vapor pressure sensor and vapor pressure sensor.

A03018
A03280
A03421
VSV Connector for
PTNK (+)
E2 (±)
E2 (±) w/o Immobiliser
w/ Immobiliser
PTNK (+)
Vapor Pressure Sensor
± DIAGNOSTICSENGINE (5S±FE)
DI±135
370 Author: Date:
12 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for vapor pressure sensor, and VSV for vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).
13 When VSV connector for vapor pressure sensor is disconnected and VSV for
EVAP is ON, measure voltage between terminals PTNK and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Disconnect the VSV connector for the vapor pressure
sensor.
(d) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
(e) Start the engine.
CHECK:
Measure voltage between terminals PTNK and E2 of the ECM
connector using the TOYOTA hand±held tester when the VSV
for the EVAP is ON.
OK:
Voltage: 2.0 V or less
OK Go to step 15.
NG

A03018A03422
ON EngineStart
Stop
VSV for Vapor
Pressure
Sensor
OFFOFF
ON
VSV for
EVAP
5 sec. 5 sec.
PTNK
(+)E2
(±) w/o Immobiliser
w/ Immobiliser
PTNK (+) E2(±)
DI±136
± DIAGNOSTICSENGINE (5S±FE)
371 Author: Date:
14 Check vacuum hoses between charcoal canister and VSV for vapor pressure
sensor, and vapor pressure sensor and VSV for vapor pressure sensor.
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
15 Check the charcoal canister.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Remove the fuel tank cap.
(d) Disconnect the VSV connector for the vapor pressure
sensor.
(e) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
(f) Start the engine.
(g) The VSV for the EVAP is ON by the TOYOTA hand±held
tester and remains on for 5 sec.
CHECK:
Measure voltage between terminals PTNK and E2 of the ECM
connector 5 sec. after switching the VSV for the EVAP from ON
to OFF.
OK:
Voltage: 2.5 V or less
NG Replace charcoal canister.
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±137
372 Author: Date:
16 Remove charcoal canister and check it (See page EC±5)
NG Replace charcoal canister.
OK
17 Check 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 ECM (See page IN±31).
OBD II scan tool (excluding TOYOTA hand±held tester):
HINT:
If DTC P0441 (Evaporative Emission Control System Incorrect Purge Flow), P0446 (Evaporative Emission
Control System Vent Control Malfunction) or P0450 (Evaporative Emission Control System Pressure Sensor
Malfunction) is output after DTC P0440 (Evaporative Emission Control System Malfunction), first trouble-
shoot DTC P0441, P0446 or P0450. If no malfunction is detected, troubleshoot DTC P0440 next.
1 Check VSV connector for EVAP, VSV connector for vapor pressure sensor and
vapor pressure sensor connector for looseness and disconnection.
NG Repair or connect VSV or sensor connector.
OK

DI±138
± DIAGNOSTICSENGINE (5S±FE)
373 Author: Date:
2 Check vacuum hoses ((1), (4), (5), (6), (7), (8) and (9) on page DI±122).
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
3 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
4 Check voltage between terminals PTNK and E2 of ECM connector
(See page DI±122, step 10).
OK Go to step 6.
NG
5 Check for open and short in harness and connector between vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.