TOYOTA HIGHLANDER 2001 Service Repair Manual

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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377 Author
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:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
1 CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0420)
(a) Read the DTC using the hand-held tester or the OBD II scan tool.
Result:
Display (DTC Output)Proceed to
Only P0420 is outputA
P0420 and other DTCs are outputB
HINT:
If any other codes besides P0420 are output, perform the troubleshooting for those codes first.
B GO TO RELEVANT DTC CHART
(See page 05-48)
A
2 CHECK FOR EXHAUST GAS LEAKAGE
NG REPAIR OR REPLACE EXHAUST GAS
LEAKAGE POINT
OK
3 INSPECT AIR FUEL RATIO SENSOR (BANK 1 SENSOR 1) (See page 12-6)
NG REPLACE AIR FUEL RATIO SENSOR
OK
4 INSPECT HEATED OXYGEN SENSOR (See page 05-1 18)
OK: During air-fuel ratio feedback, the O2S's output alternates between rich and lean.
NG REPLACE HEATED OXYGEN SENSOR
OK
REPLACE EXHAUST MANIFOLD AND FRONT EXHAUST PIPE

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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
HINT:
Hand-held tester only:

The following procedure enables a technician to identify a trouble area if there is a malfunction in front
A/F sensor or rear heated oxygen sensors other than the catalyst converter, or the malfunction that
indicates the actual air-fuel ratio extremely RICH or LEAN.
It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation. The
A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble
areas are malfunctioning or not.
(a) Perform the ACTIVE TEST A/F CONTROL operation.
HINT:
The A/F CONTROL operation lowers the injection volume 12.5 % or increases the injection volume 25 %.
(1) Connect the hand-held tester to the DLC3 on the vehicle.
(2) Turn the ignition switch ON.
(3) Warm up the engine by running the engine speed at 2,500 rpm for approximately 90 seconds.
(4) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
(5) Perform the A/F CONTROL operation with the engine idle (press the right or left button).
Result:
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume
+25 % " rich output: More than 0.5 V
-12.5 % " lean output: Less than 0.4 V

+25 %
-12.5 %
More than 3.35 V
Less than 3.0 V
Case 1
Case 2
Case 3
Case 4
Output voltage of A/F sensor
(sensor 1)
Injection volume
Output voltage
Output voltage of heated oxygen
sensor (sensor 2)Main suspect
trouble area
OK
+25 %
-12.5 %
More than 3.35 V
Less than 3.0V
Injection volume
Output voltage
+25 %
-12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
A/F sensor
(A/F sensor, heater, A/F sen-
sor circuit)
+25 %
-12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
+25 %
-12.5 %
Injection volume
Output voltage
NG
+25 %
-12.5 %
Injection volume
Output voltage
NG
+25 %
-12.5 %
Injection volume
Output voltage
NG
+25 %
-12.5 %
Injection volume
Output voltage
NGExtremely rich or lean actual
air-fuel ratio
(Injector, fuel pressure, gas
leakage in exhaust system,
etc.) OK
OK
OK
Almost
No reaction
Almost
No reaction
Almost
No reaction Almost
No reaction
'
Heated oxygen sensor
(heated oxygen sensor,
heater, heated oxygen sensor
circuit)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
NOTICE:
The A/F sensor output has a few seconds of delay and the heated oxygen sensor output has about
20 seconds of delay at maximum.
The following of A/F CONTROL procedure enables a technician to check and graph the voltage outputs of
both the heated oxygen sensors.
For displaying the graph, enter ºACTIVE TEST / A/F CONTROL / USER DATAº, select ºAFS B1S1 and O2S
B1S2º by pressing ºYESº and push ºENTERº. Then press ºF4º.

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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0441 EVAPORATIVE EMISSION CONTROL
SYSTEM INCORRECT PURGE FLOW
DTC SUMMARY
DTCsMonitoring ItemsMalfunction Detection ConditionsTrouble AreasDetection
TimingsDetection
Logic
P0441
Purge VSV (Vacuum
Switching Valve) stuck
open
Vacuum pump creates negative pressure
(vacuum) in EVAP system and EVAP sys-
tem pressure measured. 0.02 inch leak
pressure standard is measured at the start
and at the end of the leak check.
If stabilized pressure higher than [second
0.02 inch leak pressure standard x 0.2],
ECM determines that purge VSV stuck
open

Purge VSV

Connector/wire harness
(Purge VSV - ECM)

ECM

Pump module

Leakage from EVAP system
While ignition
Switch OFF2 trip
P0441Purge VSV stuck closed
After EVAP leak check performed, purge
VSV turned ON (open), and atmospheric
air introduced into EVAP system. 0.02 inch
leak pressure standard is measured at the
start and at the end of the leak check.
If pressure does not return to near atmo-
spheric pressure, ECM determines that
purge valve stuck closed

Purge VSV

Connector/wire harness
(Purge VSV - ECM)

ECM

Pump module

Leakage from EVAP system
While ignition
Switch OFF2 trip
P0441Purge flow
While engine running, following conditions
successively met:

Negative pressure not created in EVAP
system when purge VSV turned ON
(open)

EVAP system pressure change less than
0.5 kPa (3.75 mmHg) when vent valve
turned ON (closed)

Atmospheric pressure change before and
after purge flow monitor less than 0.1 kPa
(0.75 mmHg)

Purge VSV

Connector/wire harness
(Purge VSV - ECM)

Leakage from EVAP line
(Purge VSV - Intake manifold)

ECM
While engine
running2 trip
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) Inspection Procedure (see page
05-317).
INSPECTION PROCEDURE
Refer to the EVAP Inspection Procedure (see page 05-317).
05HB6-02

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
The two monitors, Key-Off and Purge Flow, are used to detect malfunctions relating to DTC P0441. The
Key-Of f monitor is initiated by the ECM internal timer, known as the soak timer, 5 hours* after the ignition
switch is turned to OFF. The purge flow monitor runs while the engine is running.
1. KEY-OFF MONITOR
5 hours* after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacu-
um) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions
based on the EVAP pressure.
HINT:
*: If the engine coolant temperature is not below 35C (95F) 5 hours after the ignition switch is turned off,
the monitor check starts 2 hours later. If it is still not below 35C (95F) 7 hours after the ignition switch is
turned off, the monitor check starts 2.5 hours later.
SequenceOperationsDescriptionsDuration
-ECM activationActivated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to OFF.-
AAtmospheric pressure
measurement
Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to
register atmospheric pressure.
If EVAP pressure is not between 70 kPa and 110 kPa (525 mmHg and 825 mmHg), ECM
cancels EVAP system monitor.
10 seconds
B
First 0.02 inch leak
pressure measure-
mentIn order to determine 0.02 inch leak pressure standard, vacuum pump creates negative pres-
sure (vacuum) through 0.02 inch orifice and then ECM checks if vacuum pump and vent
valve operate normally.
60 seconds
CEVAP system pres-
sure measurement
Vent valve turned ON (closed) to shut EVAP system.
Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then
measured.
Write down the measured value as it will be used in the leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.
15 minutes*
DPurge VSV monitorPurge VSV opened and then EVAP system pressure measured by ECM.
Large increase indicates normal.10 seconds
E
Second 0.02 inch leak
pressure measure-
mentLeak check is performed after second 0.02 inch leak pressure standard is measured.
If stabilized system pressure higher than second 0.02 inch leak pressure standard, ECM
determines that EVAP system leaking.
60 seconds
FFinal checkAtmospheric pressure measured and then monitoring result recorded by ECM.-
* If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

A96746
Fuel Tank Canister
Vacuum Pump: OFF Pressure Sensor 0.02 Inch Orifice
Pump Module
Operation A: Atmospheric Pressure Measurement
Vent Valve: OFF (vent)
Operation D: Purge VSV monitor Operation B, E: 0.02 Inch Leak Pressure Measurement
Negative
Pressure Atmospheric
Pressure Air Filter
Purge VSV: OFFOFF (vent)
ON
OFF
OFF
ON
ON (closed)ON
ON
ON (closed)
Operation C: EVAP System Pressure Measurement
G36775
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Leak Pressure
sec NegativeONON
Sequence
TimeA
10
sec60
Within 15 minutes
sec ON
First 0.02 inch
BCD
OK Malfunction
ON: Open
OFF: Closed
OFF: Vent ON: Closed
10
Standard
sec60
E EVAP Pressure when Purge VSV Stuck Open:
Leak PressureSecond 0.02 inch
Standard x 0.2
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- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
(a) Purge VSV stuck open
In operation C, the vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission)
system. The EVAP system pressure is then measured by the ECM using the pressure sensor. If the stabilized
system pressure is higher than [second 0.02 inch leak pressure standard x 0.2], the ECM interprets this as
the purge VSV (Vacuum Switching Valve) being stuck open. The ECM illuminates the MIL and sets the DTC
(2 trip detection logic).

G36776
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Leak Pressure
sec NegativeONON
Sequence
TimeA
10
sec60
Within 15 minutesON
First 0.02 inch
BCD
OK
Malfunction
ON: Open
OFF: Closed
OFF: Vent ON: Closed
10
Standard
sec60
E EVAP Pressure when Purge VSV Stuck Closed:
A71563
EVAP Pressure
During Purge Flow Monitor:
VSV
EVAP
PressureOpen
1st
Monitor2nd
Monitor
ON (closed)
Purge
Valve Vent
OK
OK
Malfunction
0.1 kPa
0.5 kPa
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(b) Purge VSV stuck closed
In operation D, the pressure sensor measures the EVAP system pressure. The pressure measurement for
purge VSV monitor is begun when the purge VSV is turned ON (open) after the EVAP leak check. When
the measured pressure indicates an increase of 0.3 kPa (2.25 mmHg) or more, the purge VSV is functioning
normally. If the pressure does not increase, the ECM interprets this as the purge VSV being stuck closed.
The ECM illuminates the MIL and sets the DTC (2 trip detection logic).
2. PURGE FLOW MONITOR
The purge flow monitor consists of the two step monitors. The
1st monitor is conducted every time and the 2nd monitor is acti-
vated if necessary.

The 1st monitor
While the engine is running and the purge VSV
(Vacuum Switching Valve) is ON (open), the ECM
monitors the purge flow by measuring the EVAP
pressure change. If negative pressure is not
created, the ECM begins the 2nd monitor.

The 2nd monitor
The vent valve is turned ON (closed) and the EVAP
pressure is then measured. If the variation in the
pressure is less than 0.5 kPa (3.75 mmHg), the
ECM interprets this as the purge VSV being stuck
closed, and illuminates the MIL and sets DTC
P0441 (2 trip detection logic).
Atmospheric pressure check:
In order to ensure reliable malfunction detection, the variation
between the atmospheric pressures, before and after conduc-
tion of the purge flow monitor, is measured by the ECM.

05-200
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
OBD II MONITOR SPECIFICATIONS (Key-off Monitor)
Monitor Strategy
Required Sensors/ComponentsPurge VSV and pump module
Frequency of OperationOnce per driving cycle
DurationWithin 15 minutes (varies with fuel in tank)
MIL Operation2 driving cycles
Sequence of OperationNone
Typical Enabling Conditions
The monitor will run whenever these DTCs are not presentSee page 05-16
EVAP key-off monitor runs when all of the following condi-
tions met-
Atmospheric pressure525 to 825 mmHg (70 to 110 kPa)
Battery voltage10.5 V or more
Vehicle speedBelow 4 km/h (2.5 mph)
Ignition switchOFF
Engine conditionNot running
Time after engine stopped5 hours
FTP sensor malfunction (P0450, P0452, P0453)Not detected
Purge VSVNot operated by scan tool
Vent valveNot operated by scan tool
Leak detection pumpNot operated by scan tool
Both of the following conditions are met before IG switch
OFF:Condition 1 and 2
1. Duration that vehicle is driven5 min. or more
2. Purge flowExecuted
ECT4.4 to 35C (40 to 95F)
IAT4.4 to 35C (40 to 95F)
Example of re-start time
First time7 hours
Second time9 hours and 30 min.
Key-of f monitor sequence: 1 to 8
1. Atmospheric pressure
Next sequence is run if following condition met-
Atmospheric pressure change for 10 sec.Within 2.25 mmHg (0.3 kPa) for 1 sec.
2. First reference pressure
Next sequence is run if all of following conditions metCondition 1, 2 and 3
1. FTP when 4 sec. after reference pressure measurement-7.5 mmHg (-1 kPa) or less
2. Reference pressure-36.47 to -7.93 mmHg (-4.85 to -1.057 kPa)
3. Reference pressureSaturated
3. Vent valve stuck closed check
Next sequence is run if following condition met-
FTP change for 10 sec. after vent valve ON (closed)2.25 mmHg (0.3 kPa) or more
4. Vacuum introduction and leak
Next sequence is run if both of following conditions metCondition 1 and 2
1. Vacuum introduction timeWithin 15 min.
2. FTPFTP was saturated
5. Purge VSV stuck closed check
Next sequence is run if following condition met-
FTP change for 10 sec. after purge VSV ON (open)2.25 mmHg (0.3 kPa) or more

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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6. Second reference pressure measurement
Next sequence is run if all of following conditions metCondition 1, 2, 3 and 4
1. FTP when 4 sec. after reference pressure measurement-7.5 mmHg (-1 kPa) or less
2. Reference pressure-36.47 to -7.93 mmHg (-4.85 to -1.057 kPa)
3. Reference pressureSaturated
4. Reference pressure difference between first and secondLess than 5.25 mmHg (0.7 kPa)
7. Leak check
Next sequence is run if following condition met-
FTP when vacuum introduction was completeLower than second reference pressure
8. Atmospheric pressure
Monitor is complete if following-
Atmospheric pressure difference between sequence 1 and 8Within 2.25 mmHg (0.3 kPa)
Typical Malfunction Thresholds
Purge VSV stuck open
FTP when vacuum introduction was completeHigher than reference pressure x 0.2
Purge VSV stuck closed
FTP change for 10 seconds after purge VSV ON (open)Less than 2.25 mmHg (0.3 kPa)
OBD II MONITOR SPECIFICATIONS (Purge Flow Monitor)
Monitor Strategy
Required Sensors/ComponentsPurge VSV and pump module
Frequency of OperationOnce per driving cycle
DurationWithin 30 seconds
MIL Operation2 driving cycles
Sequence OperationNone
Typical Enabling Conditions
The monitor will run whenever these DTCs are not presentSee page 05-16
EngineRunning
ECT4.4C (40F) or more
IAT4.4C (40F) or more
FTP sensor malfunctionNot detected
Purge VSVNot operated by scan tool
EVAP system checkNot operated by scan tool
Battery voltage10 V or more
Purge duty cycle8 % or more
Typical Malfunction Thresholds
Both of the following conditions are met:Condition 1 or 2
1. FTP change when purge operation is startedLess than 0.75 mmHg (0.1 kPa)
2. FTP change during purge operation when vent valve is
closedLess than 3.75 mmHg (0.5 kPa)
MONITOR RESULT (MODE 06)
Refer to page 05-317 for detailed information on Monitor Result.

- DIAGNOSTICSSFI SYSTEM (3MZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0442 EVAPORATIVE EMISSION CONTROL
SYSTEM LEAK DETECTED (SMALL LEAK)
DTC P0455 EVAPORATIVE EMISSION CONTROL
SYSTEM LEAK DETECTED (GROSS LEAK)
DTC P0456 EVAPORATIVE EMISSION CONTROL
SYSTEM LEAK DETECTED (VERY SMALL
LEAK)
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
Leak Check graphic).
P0442, P0455 and P0456
A leak in the evaporative emission system prompts the ECM to set DTC P0442, P0455 or P0456.
The ECM checks if the EVAP has leaks. First, the ECM opens the EVAP VSV while the CCV is closed. After
a sufficient amount of time has passed, a high negative pressure(vacuum) will develop in the fuel tank as
air is drawn into the intake manifold. The EVAP VSV is then closed. The ECM then monitors the pressure
increase (loss of vacuum) in the fuel tank. If the pressure rises beyond a specified amount, the ECM deter-
mines that the system has a leak, turns on the MIL and outputs a DTC.
The ECM has separate DTCs for small and large leaks:
(1) DTC P0442 is set when the internal fuel tank pressure has a large increase and the EVAP system
has a small leak.
(2) DTC P0455 is set when the EVAP system has a very large leak. The ECM tries to create negative
pressure (vacuum) in the fuel tank by opening the EVAP VSV while the CCV is closed. However,
the fuel tank pressure does not decrease beyond a specified threshold.
(3) DTC P0456 is set when the internal fuel tank pressure increases slightly and the EVAP system
has a very small leak.
05MOQ-01