engine TOYOTA HIGHLANDER 2001 Service Repair Manual

A79199
Vehicle Speed
38 to 75 mph
(60 to 120 km/h)
Idling
Ignition Switch OFF
3 to 5 minutes
Time 2 minutes
(a), (b)(c)(d)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
CONFIRMATION DRIVING PATTERN
(a) Connect the hand-held tester to the DLC3.
(b) Switch the hand-held tester from normal mode to check mode (see page 05-40).
(c) Start the engine and warm it up with all the accessory switched OFF.
(d) Drive the vehicle at 38 to 75 mph (60 to 120 km/h) and engine speed at 1,400 to 3,200 rpm for 3 to
5 minutes.
HINT:
If a malfunction exists, the MIL will be illuminated during step (d).
NOTICE:
If the conditions in this test are not strictly followed, detection of a malfunction will not occur. If you
do not have a hand-held tester, turn the ignition switch OFF after performing steps (c) and (d), then
perform steps (c) and (d) again.
INSPECTION PROCEDURE
HINT:
Hand-held tester only:
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 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:
A/F sensor reacts in accordance with increase and decrease of injection volume:
+25 % " RICH output: Less than 3.0 V
-12.5 % " LEAN output: More than 3.35 V
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
+25 % " RICH output: More than 0.55 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) 05-274
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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.
The following A/F CONTROL procedure enables a technician to check and graph the voltage outputs of both
the A/F sensor and the heated oxygen sensor.
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.
HINT:

If DTC P2195 or P2196 is displayed, check bank 1 sensor 1 circuit.

A low A/F sensor voltage could be caused by a RICH air-fuel mixture. Check for conditions that would
cause the engine to run with a RICH air-fuel mixture.

A high A/F sensor voltage could be caused by a LEAN air-fuel mixture. Check for conditions that would
cause the engine to run with a LEAN air-fuel mixture.

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records
the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can
help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel
ratio was lean or rich, and other data from the time the malfunction occurred.

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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
1 CHECK OTHER DTC OUTPUT (IN ADDITION TO A/F SENSOR DTC)
(a) Read the DTC using the hand-held tester or the OBD II scan tool.
Result:
DisplayProceed to
A/F sensor circuit DTC are outputA
A/F sensor circuit DTC and other codes are outputB
HINT:
If any other codes besides A/F sensor DTC are output, perform the troubleshooting for those DTCs first.
B GO TO RELEVANT DTC CHART
(See page 05-48)
A
2 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (OUTPUT VOLT-
AGE OF A/F SENSOR)
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Warm up the A/F sensor (bank 1 sensor 1) by running the engine at 2,500 rpm for approximately 90
seconds.
(c) Read A/F sensor voltage output on the hand-held tester or the OBD II scan tool.
(d) Hand-held tester only:
On the hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / SNAPSHOT
/ MANUAL SNAPSHOT / USER DATA. Read the values.
(e) Select ºAFS B1S1 / ENGINE SPDº and press YES.
(f) Monitor the A/F sensor voltage carefully.
(g) Check the A/F sensor voltage output under the following conditions:
(1) Allow the engine to idle for 30 seconds.
(2) Run the engine at approximately 2,500 rpm. Do not suddenly change the rpm.
(3) Raise the engine to 4,000 rpm and quickly release the accelerator pedal so that the throttle is
fully closed.
Standard:
Condition (1) and (2)
Voltage change of 3.3 V (0.66 V)* (between approximately 3.1 to 3.5 V) as shown in the illustra-
tion.
Condition (3)
A/F sensor voltage increases to 3.8 V (0.76 V)* or more during engine deceleration when fuel
is cut as shown in the illustration.
*: Voltage when using the OBD II scan tool.

A72304
Engine
RPMEngine
RPM (1) Idle (2) Approximately 2,500 rpm
Fuel Cut
When A/F sensor circuit is malfunctioning,
voltage output does not change A/F
Sensor
Voltage A/F
Sensor
Voltage
(1) Idle
Fuel Cut (3) Approximately 4,000 rpm
ºCondition (1), (2)º
Change of approximately 3.3 V Normal Condition
Malfunction Condition
ºCondition (3)º
3.8 V or More(1) Idle (2) Approximately 2,500 rpm(3) Approximately 4,000 rpm
(1) Idle
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
HINT:

Whenever the A/F sensor output voltage remains at approximately 3.3 V (0.660 V)* (see ºMalfunction
Conditionº graphic) under any condition as well as the above conditions, the A/F sensor may have an
open circuit. This will happen also when the A/F sensor heater has an open circuit.

Whenever the A/F sensor output voltage remains at a certain value of approximately 3.8 V (0.76 V)*
or more, or 2.8 V (0.56 V)* or less (see ºMalfunction Conditionº graphic) under any condition as well
as the above conditions, the A/F sensor may have a short circuit.

The ECM will stop fuel injection (fuel is cut) during engine deceleration. This will cause a LEAN condi-
tion and should result in a momentary increase in the A/F sensor output voltage.

The ECM must establish a closed throttle position learned value to perform fuel cut. If the battery termi-
nal has been disconnected, the vehicle must be driven over 10 mph (16 km/h) to allow the ECM to learn
the closed throttle position.

When the vehicle is driven:
The output voltage of the A/F sensor may be below 2.8 V (0.76 V)* during fuel enrichment. For the
vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when
trying to overtake another vehicle. The A/F sensor is functioning normally.

The A/F sensor is a current output element, and therefore the current is converted into voltage inside
the ECM. If measuring voltage at connectors of A/F sensor or ECM, you will observe a constant volt-
age.
*: Voltage when using the OBD II scan tool.
OK Go to step 13
NG

A52607
AF-AF+
A6
A/F sensor
B60778
5
12 312
5
3
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
(a) Disconnect the A6 A/F sensor connector.
(b) Measure the resistance of the A/F sensor terminals.
Standard:
Tester ConnectionConditionSpecified Condition
1 (HT) - 2 (+B)20C (68F)1.8 to 3.4 W
1 (HT) - 4 (AF-)-10 kW or higher
NG REPLACE AIR FUEL RATIO SENSOR
OK
4 INSPECT RELAY (EFI)
(a) Remove the EFI relay from the engine room J/B.
(b) Measure the resistance of the EFI relay.
Standard:
Tester ConnectionSpecified Condition
3 - 510 kW or higher
3 - 5Below 1 W
(when battery voltage is applied to terminals 1 and 2)
NG REPLACE RELAY
OK

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MONITOR DESCRIPTION
The air-fuel ratio (A/F) sensor varies its voltage output in proportion to the air-fuel ratio. If impedance (alter-
nating current resistance) or voltage output of the sensor deviates greatly from the standard, the ECM deter-
mines that an open or short is in the A/F sensor circuit.
MONITOR STRATEGY
Related DTCs
P2238: A/F sensor (Bank1) open circuit between AF+ and AF-
P2238: A/F sensor (Bank1) short circuit between AF+ and AF-
P2238: A/F sensor (Bank 1) short circuit between AF+ and GND
P2239: A/F sensor (Bank 1) short circuit between AF+ and +B
P2252: A/F sensor (Bank 1) short circuit between AF- and GND
P2253: A/F sensor (Bank 1) short circuit between AF- and +B
Required sensors/ components (Main)A/F sensor
Required sensors/ components (Related)ECT sensor, CKP sensor
Frequency of operationOnce per driving cycle
Duration10 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
P2238 (open circuit between AF+ and AF-):
Duration while all of the following conditions are met:20 seconds or more
AF+ terminal voltage0.5 to 4.5 V
AF- terminal voltage0.5 to 4.5 V
Difference between AF+ terminal and AF- terminal voltages0.1 to 0.8 V
ECT20C (68F) or more
Engine conditionRunning
Time after engine start20 seconds or more
Fuel-cutOFF
A/F sensor heater duty cycle0.5% or more
Time after A/F sensor heating20 seconds or more
Battery voltage10.5 V or more
Ignition switchON
Others:
Battery voltage10.5 V or more
Ignition switchON

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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TYPICAL MALFUNCTION THRESHOLDS
P2238 (Open circuit between AF+ and AF-):
A/F sensor admittanceBelow 0.022 1/ohm
P2238 (Short circuit between AF+ and GND):
AF+ terminal voltage0.5 V or less
P2238 (Short circuit between AF+ and AF-):
Difference between AF+ terminal and AF- terminal voltages0.1 V or less
P2239 (Short circuit between AF+ and +B):
AF+ terminal voltageMore than 4.5 V
P2252 (Short circuit between AF- and GND):
AF- terminal voltage0.5 V or less
P2253 (Short circuit between AF- and +B):
AF- terminal voltageMore than 4.5 V
WIRING DIAGRAM
Refer to DTC P2195 on page 05-269.
INSPECTION PROCEDURE
HINT:
Hand-held tester only:
The malfunctioning area can be found by the ACTIVE TEST A/F CONTROL operation. The A/F CONTROL
operation can determine if the A/F sensor, heated oxygen sensor or other suspected trouble areas are mal-
functioning or not.
(a) Perform the ACTIVE TEST A/F CONTROL operation.
HINT:
The A/F CONTROL operation lowers the injection volume by 12.5 % or increases the injection volume by
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 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 idling (press the right or left button).
Result:
A/F sensor reacts in accordance with increase and decrease of injection volume:
+25 % " RICH output: Less than 3.0 V
-12.5 % " LEAN output: More than 3.35 V
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
+25 % " RICH output: More than 0.55 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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475 Author
: Date
:
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 A/F CONTROL procedure enables a technician to check and graph the voltage outputs of both
the A/F sensor and the heated oxygen sensor.
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.
HINT:

If DTC P2237, P2238, P2239, P2251, P2252 or P2253 is displayed, check the bank 1 sensor 1 circuit.

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records
the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can
help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel
ratio was lean or rich, and other data from the time the malfunction occurred.

A52607
AF-AF+
A6
A/F sensor
B60778
5
12 312
5
3
05-286
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
1 INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
(a) Disconnect the A6 A/F sensor connector.
(b) Measure the resistance of the A/F sensor terminals.
Standard:
Tester ConnectionConditionSpecified Condition
1 (HT) - 2 (+B)20C (68F)1.8 to 3.4 W
1 (HT) - 4 (AF-)-10 kW or higher
NG REPLACE AIR FUEL RATIO SENSOR
OK
2 INSPECT RELAY (EFI)
(a) Remove the EFI relay from the engine room J/B.
(b) Measure the resistance of the EFI relay.
Standard:
Tester ConnectionSpecified Condition
3 - 510 kW or higher
3 - 5Below 1 W
(when battery voltage is applied to terminals 1 and 2)
NG REPLACE RELAY
OK

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
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)(From August, 2004)
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:
MONITOR DESCRIPTION
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 them 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.