o2 sensor TOYOTA HIGHLANDER 2001 Service Repair Manual

A80018
H10
Heated Oxygen Sensor
+B HT
E1 OX
05-78
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
268 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR RESULT
Refer to page 05-24 for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (see page 05-26).

TID (Test Identification Data) is assigned to each emissions-related component.

TLT (Test Limit Type):
If TLT is 0, the component is malfunctioning when the test value is higher than the test limit.
If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.

CID (Component Identification Data) is assigned to each test value.

Unit Conversion is used to calculate the test value indicated on generic OBD ll scan tools.
TID $04: HO2S heater
TLTCIDUnit ConversionDescription of Test DataDescription of Test Limit
1$02Multiply by 0.000076
(A)Maximum HO2S heater current
(Bank 1 Sensor 2)Malfunction threshold for HO2S heater
WIRING DIAGRAM
Refer to DTC P0136 on page 05-1 18.
INSPECTION PROCEDURE
HINT:
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 deter-
mine 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.
1 INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
(a) Disconnect the H10 heated oxygen sensor connector.
(b) Measure the resistance of the heated oxygen sensor ter-
minals.
Standard:
Tester ConnectionConditionSpecified Condition
H10-2 (HT) - H10-1 (+B)20C (68F)11 to 16 W
H10-2 (HT) - H10-1 (+B)800C (1,472F)23 to 32 W
NG REPLACE HEATED OXYGEN SENSOR
OK

A81695
A80019A91528
Wire Harness Side
E8
ECM
H10
Heated Oxygen Sensor
HT +B
OX E1 HT1B
A80019
A90291A91529
Wire Harness Side
H10
Heated Oxygen Sensor
HT
+B
OX
E1
EFI RelayEngine Room J/B
05-80
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
270 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 CHECK WIRE HARNESS (ECM - HEATED OXYGEN SENSOR, HEATED OXYGEN
SENSOR - EFI RELAY)
(a) Check the wire harness between the ECM and heated ox-
ygen sensor.
(1) Disconnect the E8 ECM connector.
(2) Disconnect the H10 heated oxygen sensor connec-
tor.
(3) Measure the resistance of the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
H10-2 (HT) - E8-21 (HT1B)Below 1 W
H10-2 (HT) or E8-21 (HT1B) - Body ground10 kW or higher
(b) Check the wire harness between the heated oxygen sen-
sor and EFI relay.
(1) Disconnect the H10 heated oxygen sensor connec-
tor.
(2) Remove the EFI relay from the engine room J/B.
(3) Measure the resistance of the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
H10-1 (+B) - J/B EFI relay terminal 3Below 1 W
H10-1 (+B) or J/B EFI relay terminal 3 -Body ground10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
REPLACE ECM (See page 10-9)

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
Operation C: EVAP System Pressure Measurement
Air Filter
Purge VSV: OFFOFF (vent)
ON
OFF
OFF
ON
ON (closed)ON
ON
ON (closed)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)(From August, 2004)
05-191
381 Author
: Date
:
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) after 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.

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)(From August, 2004)
05-193
383 Author
: Date
:
OBD II MONITOR SPECIFICATIONS
Monitor Strategy
Required Sensors/ComponentsPump module
Frequency of OperationOnce per driving cycle
DurationWithin 15 minutes (varies with amount of 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

A80089
AB B+
Power Transistor
Platinum Hot Wire
(Heater)
Output
Voltage
Temperature
Sensor
Platinum Hot Wire (Heater)
Temperature Sensor
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-81
271 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0100 MASS OR VOLUME AIR FLOW CIRCUIT
DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT
LOW INPUT
DTC P0103 MASS OR VOLUME AIR FLOW CIRCUIT
HIGH INPUT
CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses
this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MAF meter,
there is a heated platinum wire exposed to the flow of intake air.
By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incom-
ing air cools the wire and an internal thermistor, changing their resistance. To maintain a constant current
value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is pro-
portional to the air flow through the sensor. The ECM interprets this voltage as the intake air amount.
The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No.DTC Detection ConditionTrouble Area
P0100When MAF meter circuit has an open or a short for more than
3 seconds
Open or short in MAF meter circuit

MAF meter

ECM
P0102When MAF meter circuit has an open for more than 3 seconds
Same as DTC No. P0100
P0103When MAF meter circuit has a short for more than 3 seconds
Same as DTC No. P0100
HINT:
After confirming DTC P0100, P0102 or P0103, use the hand-held tester or the OBD II scan tool to confirm
the MAF ratio from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL).
Air Flow Value (g/s)Malfunction
Approximately 0.0
Open in MAF meter power source circuit

Open or short in VG circuit
271.0 or more
Open in EVG circuit
05ESV-05

05-82
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
272 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
If there is a defect in the sensor, or an open or short circuit, the voltage level will deviate from the normal
operating range. The ECM interprets this deviation as a defect in the MAF meter and sets a DTC.
Example:
The sensor voltage output is less than 0.2 V or more than 4.9 V and either condition continues for more than
3 seconds.
MONITOR STRATEGY
Related DTCs
P0100: MAF meter range check (Chattering)
P0102: MAF meter range check(Low voltage)
P0103: MAF meter range check (High voltage)
Required sensors / components (Main)MAF Meter
Required sensors / components (Related)CKP (Crank shaft position) sensor
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate: Engine RPM is less than 4,000 rpm
2 driving cycles: Engine RPM is 4,000 rpm or more
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-16
TYPICAL MALFUNCTION THRESHOLDS
P0100:
MAF meter voltageLess than 0.2 V, or more than 4.9 V
P0102:
MAF meter voltageLess than 0.2 V
P0103:
MAF meter voltageMore than 4.9 V
COMPONENT OPERATING RANGE
MAF meter voltageBetween 0.4 and 2.2 V

A54396
A90291A90959
Wire Harness Side
M1
MAF Meter
+B (+)
EFI RelayEngine Room J/B
A76903
EVG
E7
ECM
05-86
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
276 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
5 CHECK WIRE HARNESS (MAF METER - EFI RELAY)
(a) Disconnect the M1 MAF meter connector.
(b) Remove the EFI relay from the engine room J/B.
(c) Measure the resistance of the wire harness side connec-
tors.
Standard:
Tester ConnectionSpecified Condition
M1-1 (+B) - J/B EFI relay terminal 3Below 1 W
M1-1 (+B) or J/B EFI relay terminal 3 -Body ground10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
INSPECT ECM POWER SOURCE CIRCUIT (See page 05-312)
6 INSPECT ECM (SENSOR GROUND)
(a) Measure the resistance of the ECM connector.
Standard:
Tester ConnectionSpecified Condition
E7-29 (EVG) - Body groundBelow 1 W
NG REPLACE ECM (See page 10-9)
OK

05-88
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
278 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0101 MASS OR VOLUME AIR FLOW CIRCUIT
RANGE/PERFORMANCE PROBLEM
CIRCUIT DESCRIPTION
Refer to DTC P0100 on page 05-81.
DTC No.DTC Detection ConditionTrouble Area
P0101

High voltage:
Conditions (a), (b) and (c) continue for more than 10 seconds
(2 trip detection logic):
(a) Engine speed less than 2,000 rpm
(b) Engine coolant temperature 70C (158F) or higher
(c) Voltage output of Mass Air Flow (MAF) meter more than 2.2
V (varies with Throttle Position [TP] sensor voltage)

Low voltage:
Conditions (a) and (b) continue for more than 10 seconds
(2 trip detection logic):
(a) Engine speed more than 300 rpm
(b) Voltage output of MAF meter less than 0.65 V
(varies with TP sensor voltage)

MAF meter
MONITOR DESCRIPTION
The MAF meter is a sensor that measures the amount of air flowing through the throttle valve. The ECM uses
this information to determine the fuel injection time and to provide an appropriate air-fuel ratio.
Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air. By applying
a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of incoming air
cools both the wire and an internal thermistor, changing their resistance. To maintain a constant current val-
ue, the ECM varies the voltage applied to these components of the MAF meter. The voltage level is propor-
tional to the air flow through the sensor, and the ECM uses it to calculate the intake air volume.
If there is a defect in the sensor, or an open or short in the circuit, the voltage level deviates from the normal
operating range. The ECM interprets this deviation as a malfunction in the MAF meter and sets the DTC.
Example:
If the voltage is more than 2.2 V, or less than 0.65 V while idling, the ECM determines that there is a malfunc-
tion in the MAF meter and sets the DTC.
MONITOR STRATEGY
Related DTCsP0101: MAF Meter Rationality (Low voltage)
P0101: MAF Meter Rationality (High voltage)
Required sensors/ components (Main)MAF meter
Required sensors/ components (Related)Crankshaft position sensor, ECT sensor, Throttle position sensor
Frequency of operationContinuous
Duration10 seconds
MIL operation2 driving cycles
Sequence of operationNone
051ZM-14

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-89
279 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever this DTC is not presentSee page 05-16
MAF Meter Rationality (High Voltage):
Engine RPMLess than 2,000 rpm
ECT70°C (158°F) or more
MAF meter voltage4.9 V or less
MAF Meter Rationality (Low Voltage):
Engine RPMMore than 300 rpm
MAF meter voltage0.2 V or more
Fuel cutOFF
TYPICAL MALFUNCTION THRESHOLDS
MAF Meter Rationality (High Voltage):
MAF meter voltageMore than 2.2 V (varies with throttle position sensor voltage)
MAF Meter Rationality (Low Voltage):
MAF meter voltageLess than 0.65 V (varies with throttle position sensor voltage)
WIRING DIAGRAM
Refer to DTC P0100 on page 05-81.
INSPECTION PROCEDURE
HINT:
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 deter-
mine 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.
1 CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0101)
(a) Read the DTC using the hand-held tester or the OBD II scan tool.
Result:
Display (DTC Output)Proceed to
P0101 and other DTCs are outputA
Only P0101 is outputB
HINT:
If any other codes besides P0101 are output, perform the troubleshooting for those codes first.
B REPLACE MASS AIR FLOW METER
A
GO TO RELEVANT DTC CHART (See page 05-48)

- 20 0 20 40 60 80 100
(- 4) 32 68 104 140 176 212 30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
A67628
Acceptable Fig. 1
Resistance kW
Temperature C (F)
05-90
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
280 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0110 INTAKE AIR TEMPERATURE CIRCUIT
DTC P0112 INTAKE AIR TEMPERATURE CIRCUIT LOW
INPUT
DTC P0113 INTAKE AIR TEMPERATURE CIRCUIT HIGH
INPUT
CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor, mounted on the Mass
Air Flow (MAF) meter, monitors the intake air temperature. The
IAT sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermistor increases. When the tem-
perature is high, the resistance drops. The variations in resis-
tance are reflected as changes in voltage applied to the ECM
terminal (see Fig. 1).
The IAT sensor is connected to the ECM (see below). The 5 V
power source voltage in the ECM is applied to the IAT sensor
from terminal THA via resistor R.
That is, the resistor R and the IAT sensor are connected in se-
ries. When the resistance value of the IAT sensor changes in
accordance with changes in the IAT, the voltage at terminal THA
also changes. Based on this signal, the ECM increases the fuel
injection volume to improve the driveability during cold engine
operation.
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0110Step 1
Open or short in IAT (Intake
air temperature) sensor cir-
cuit for 0.5 seconds
(1 trip detection logic)
Open or short in IAT sensor circuit

IAT sensor (built-in MAF meter)

ECM
P0112Step 4
Short in IAT sensor circuit for
0.5 seconds
(1 trip detection logic)

Same as DTC No. P0110
P0113Step 2
Open in IAT sensor circuit for
0.5 seconds
(1 trip detection logic)

Same as DTC No. P0110
HINT:
After confirming DTC P0110, P0112 or P0113, use the hand-held tester or the OBD II scan tool to confirm
the IAT from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL).
Temp. DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
0596B-07