2001 TOYOTA HIGHLANDER o2 sensor

05-570
- DIAGNOSTICSSFI SYSTEM (3MZ-FE)
760 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0446 EVAPORATIVE EMISSION CONTROL
SYSTEM VENT CONTROL CIRCUIT
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP INSPECTION PROCEDURE (see page 05-679).
INSPECTION PROCEDURE
Refer to the EVAP INSPECTION PROCEDURE (see page 05-679).
MONITOR DESCRIPTION
The ECM tests the Evaporative Emissions (EVAP) system using the fuel tank pressure sensor, Canister
Close Valve (CCV), and EVAP VSV. The ECM closes the EVAP system and creates negative pressure (vacu-
um) into it. The ECM then monitors the internal pressure using the fuel tank pressure sensor (refer to the
graphic on page 05-557).
P0446 (FOR SYSTEM DIAGRAM AND DTC DETECTION TIMING CHART, REFER TO DTC P0441
(see page 05-557))
The CCV is open under normal conditions. The CCV has the following features:
(1) After the EVAP VSV purges the EVAP from the fuel tank into the intake manifold, the CCV draws
fumes from the fuel tank into the charcoal canister.
(2) Relieves pressure inside the fuel tank when the pressure has suddenly risen.
(3) Along with the EVAP VSV, creates negative pressure (vacuum) inside the fuel tank and performs
leak tests.
The ECM checks if the CCV is ºstuck closedº. The ECM commands the CCV to open while the EVAP VSV
is open. If high negative pressure (vacuum) develops in the fuel tank and stays for more than 4 seconds,
the ECM determines that the CCV remains closed despite the open command. The ECM would then turn
on the MIL and output a DTC. The engine coolant temperature is not related to the output of this DTC.
The ECM also has a method for checking if the CCV is ºstuck openº. The ECM commands the CCV to close
while the EVAP VSV is open. If a sufficient amount of negative pressure dose not develop in the fuel tank,
the ECM determines that the CCV remains open despite the close command. The ECM would then turn on
the MIL and output a DTC.
DTC No.DTC Detection ConditionTrouble Area
P0446Open or close malfunction in CCV (2 trip detection logic)

Vacuum hose has cracks, holes, or is blocked, damaged or
disconnected

Fuel tank cap incorrectly installed

Fuel tank cap has cracks or is damaged

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

Open or short in EVAP VSV circuit

EVAP VSV

Open or short in CCV circuit

CCV

Fuel tank has cracks, holes, or is damaged

Charcoal canister has cracks, holes, or is damaged

Fuel tank over fill check valve cracks, or is damaged

ECM
05MOR-01

- DIAGNOSTICSSFI SYSTEM (3MZ-FE)
05-571
761 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCsP0446: CCV stuck open
P0446: CCV stuck close
Required sensors / components (Main)CCV, EVAP canister, EVAP hose, Fuel cap, Fuel tank and Purge VSV
Required sensors / components (Related)ECT sensor, FTP sensor, IAT sensor, MAF meter, Vehicle speed sensor
Frequency of operationOnce per driving cycle
DurationWithin 60 seconds
MIL operation2 driving cycles
Sequence operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-377
AltitudeLess than 7,870 ft. (2,400 m)
Battery voltage11 V or more
Throttle position learningCompleted
IAT at engine start - ECT at engine start-7 to 11.1C (-12.6 to 20F)
EVAP VSV and CCVNot operated test by scan tool
Either of the following conditions is metCondition 1 or 2
1. Purge duty cycle8% or more (vary with MAF)
2. Purge concentration for 30 seconds-5 %/% or more when vehicle speed is less than 10 km/h (6.25 mph)
RefuelNot refueled with engine running
FTP12.75 mmHg (-1.7 kPa) or more
ECT at engine start4.4 to 35C (39.9 to 95F)
IAT at engine start4.4 to 35C (39.9 to 95F)
IAT4.4C (39.9F) or more
Vehicle speed changeVehicle is driven by steady speed
Fuel sloshNo sloshing (i.e. fairly smooth road)
Time after engine startWithin 50 minutes
FTP change before vacuum introductionMinimum change
Fuel levelLess than 90 %
TYPICAL MALFUNCTION THRESHOLDS
CCV stuck close P0446:
Duration that the following conditions 1 and 2 are met:4 seconds or more
1. Accumulated purge volume0.5 g or more
2. FTPLess than -12.75 mmHg (-1.7 kPa)
CCV stuck open P0446:
Purge VSV stuck closedDetected

05-202
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
392 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0450 EVAPORATIVE EMISSION CONTROL SYS-
TEM PRESSURE SENSOR/SWITCH
DTC P0451 EVAPORATIVE EMISSION CONTROL SYS-
TEM PRESSURE SENSOR RANGE/PER-
FORMANCE
DTC P0452 EVAPORATIVE EMISSION CONTROL SYS-
TEM PRESSURE SENSOR/SWITCH LOW IN-
PUT
DTC P0453 EVAPORATIVE EMISSION CONTROL SYS-
TEM PRESSURE SENSOR/SWITCH HIGH IN-
PUT
DTC SUMMARY
DTCMonitoring ItemsMalfunction Detection ConditionsTrouble AreasDetection Tim-
ingsDetection
Logic
P0450Pressure sensor voltage ab-
normal fluctuationSensor output voltage rapidly fluctuates
beyond upper and lower malfunction
thresholds for 0.5 seconds.
Pump module

Connector/Wire harness
(Pump module - ECM)

ECM
EVAP monitor-
ing (ignition
OFF)

Ignition ON
1 trip
P0451Pressure sensor noisingSensor output voltage fluctuates fre-
quently in certain time period.

Pump module

Connector/Wire harness
(Pump module - ECM)

ECM
EVAP monitor-
ing (ignition
OFF)

Engine running
2 trip
P0451Pressure sensor stuckSensor output voltage does vary in cer-
tain time period.

Pump module

Connector/Wire harness
(Pump module - ECM)

ECM
EVAP monitor-
ing (ignition
OFF)
2 trip
P0452Pressure sensor voltage lowSensor output voltage is less than 0.45
V for 0.5 seconds.

Pump module

Connector/Wire harness
(Pump module - ECM)

ECM
Ignition ON

EVAP monitor-
ing (ignition
OFF)
1 trip
P0453Pressure sensor voltage highSensor output voltage is more than 4.9
V for 0.5 seconds.

Pump module

Connector/Wire harness
(Pump module - ECM)

ECM
Ignition ON

EVAP monitor-
ing (ignition
OFF)
1 trip
HINT:
The pressure sensor is built into the pump module.
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) Inspection Procedure (see page
05-317).
05IR9-02

A71562
Pressure Sensor Specification:
Output Voltage
Usable Range
4.900 V
4.150 V
1.425 V
0.450 V
Malfunction Area
Pressure
60
kPa11 0
kPa
Malfunction Area
Standard atmospheric pressure is 101.3 kPaHINT:
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-203
393 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
(a) DTC P0450: Pressure sensor voltage abnormal fluctua-
tion.
If the pressure sensor voltage output rapidly fluctuates
between less than 0.45 V and more than 4.9 V, the ECM
interprets this as an open or short circuit malfunction in
the pressure sensor or its circuit, and stops the EVAP
(Evaporative Emission) system monitor. The ECM then il-
luminates the MIL and sets the DTC (1 trip detection log-
ic).
(b) DTC P0451: Pressure sensor noising or stuck
If the pressure sensor voltage output fluctuates rapidly for
10 seconds, the ECM stops the EVAP system monitor.
The ECM interprets this as noise from the pressure sen-
sor, and stops the EVAP system monitor. The ECM then
illuminates the MIL and sets the DTC.
Alternatively, if the sensor voltage output does not
change for 10 seconds, the ECM interprets this as the
sensor being stuck, and stops the monitor. The ECM then
illuminates the MIL and sets the DTC.
(Both the malfunctions are detected by 2 trip detection
logic)
(c) DTC P0452: Pressure sensor voltage low
If the pressure sensor voltage output is below 0.45 V, the
ECM interprets this as an open or short circuit malfunction
in the pressure sensor or its circuit, and stops the EVAP
system monitor. The ECM then illuminates the MIL and
sets the DTC (1 trip detection logic).
(d) DTC P0453: Pressure sensor voltage high
If the pressure sensor voltage output is 4.9 V or more, the
ECM interprets this as an open or short circuit malfunction
in the pressure sensor or its circuit, and stops the EVAP
system monitor. The ECM then illuminates the MIL and
sets the DTC (1 trip detection logic).

05-204
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
394 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
OBD II MONITOR SPECIFICATIONS
Monitor Strategy
Required Sensors/ComponentsPump module
Frequency of OperationOnce per driving cycle: P0451 FTP sensor output ºStuckº
Continuous: P0451 FTP sensor ºNoiseº, P0450, P0452 and P0453
Duration0.5 sec.: P0450, P0452 and P0453
10 sec.: P0451
MIL OperationImmediate: P0450, P0452 and P0453
2 driving cycles: P0451
Sequence of OperationNone
Typical Enabling Conditions
P0451: FTP sensor ºNoiseº
Monitor runs whenever these DTCs are not presentSee page 05-16
Atmospheric pressure (absolute pressure)70 kPa (525 mmHg) or more, less than 110 kPa (825 mmHg)
Battery voltage10.5 V or more
Intake air temperature4.4 to 35C (40 to 95F)
FTP sensor malfunction (P0450, P0452, P0453)Not detected
Either of following conditions is met:Condition 1 or 2
1. EngineRunning
2. Time after engine stopped5 hours
Example of re-start time
First time7 hours
Second time9 hours and 30 min.
P0451: FTP sensor output ºStuckº
Monitor runs whenever these DTCs are not presentSee page 05-16
Battery voltage10.5 V or more
Intake air temperature4.4 to 35C (40 to 95F)
FTP sensor malfunction (P0450, P0452, P0453)Not detected
Atmospheric pressure (absolute pressure)Less than 70 kPa (525 mmHg), or 110 kPa (825 mmHg) or more
Time after engine stopped5 hours
Example of re-start time
First time7 hours
Second time9 hours and 30 min.
P0450, P0452 and P0453:
Monitor runs whenever these DTCs are not presentSee page 05-16
Ignition switchON
Battery voltage8 V or more
StarterOFF
Typical Malfunction Thresholds
P0450: Pressure sensor chattering
Pressure sensor voltageLess than 0.45 V, or more than 4.9 V
P0451: FTP sensor ºNoiseº
Frequency that FTP change is 2.25 mmHg (0.3 kPa) or
more10 times or more in 10 sec.
P0451: FTP sensor output ºStuckº
FTP change for 10 sec. during EVAP monitor (Reference
pressure)Less than 4.88 mmHg (0.65 kPa)
P0452: Pressure sensor low voltage
Pressure sensor voltageLess than 0.45 V

A85256
C17
Pump Module
BJ1 IO1 IM1E7
E5
E7
E5
E5
E7
E5 18
21
28
4
27
34
8VC
PPMP
E2
MPMP
VPMP
PRG
MRELECM
5V
Pressure Sensor
BJ1 IO1 IM1
BJ1 IO1 IM1
BJ1 IO1 IM1 BJ1 IO1 BJ1 IO1
EB1 16 7 13
12 3
17 15 12
14 5 14
18 16 513 4
1S28
S295 5
LG
BJ1 15
J19
J/C
BFBatteryEH
J2
J/C A AFL MAIN
W
W-B W-B
W-B
2
2I1
2F4EFI No. 2
EFI No. 1EFI Relay
2 53
113
IK3 P-L B
2B2D3
52
Y Engine Room J/BB-R
B-R
Vacuum Pump
Vent Valve
4
3
2
1
8
9Y
YY LLP
L
BRBRBR
WW
BR
RVSB
GRY-G BRBR
B-R
G 12
V4
Purge VSV 6
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-205
395 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
P0453: Pressure sensor high voltage
Pressure sensor voltageMore than 4.9 V
WIRING DIAGRAM

05-206
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
396 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
NOTICE:

When a vehicle is brought into the workshop, leave it as it is. Do not change the vehicle condi-
tion. For example, do not tighten the fuel tank cap.

Do not disassemble the pump module.

A hand-held tester is required to conduct the following diagnostic troubleshooting procedure.
1 CONFIRM DTC AND EVAP PRESSURE
(a) Connect a hand-held tester to the DLC3.
(b) Turn the ignition switch to ON (do not start the engine).
(c) Turn the tester ON.
(d) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(e) Read DTCs.
(f) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / VAPOR
PRESS.
(g) Read the EVAP (Evaporative Emission) pressure displayed on the tester.
Result:
Display (DTC Output)Test ResultsSuspected Trouble AreasProceed To
P0451'
Pressure sensorC
P0452Less than 45 kpa (430 mmHg)

Wire harness/connector (ECM - pressure
sensor)

Pressure sensor

Short in ECM circuit
A
P0453More than 120 kPa (900 mmHg)

Wire harness/connector (ECM - pressure
sensor)

Pressure sensor

Open in ECM circuit
B
B Go to step 4
C Go to EVAP INSPECTION PROCEDURE
(See page 05-317)
A

A54404
ECM
E5
21 (PPMP)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-207
397 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 CHECK HARNESS AND CONNECTOR(PUMP MODULE - ECM)
(a) Turn the ignition switch to OFF.
(b) Disconnect the E5 ECM connector.
(c) Measure the resistance between PPMP terminal of the
ECM connector and the body ground.
Result:
Test ResultsSuspected Trouble AreasProceed To
10 W or less
Wire harness/connector (ECM - pressure sensor)

Short in pressure sensor circuitA
10 kW or more
Wire harness/connector (ECM - pressure sensor)

Short in ECM circuitB
(d) Reconnect the ECM connector.
B Go to step 7
A