2001 TOYOTA HIGHLANDER Engine mount

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

- 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

05-134
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
324 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-16
Fuel system statusClosed Loop
Battery voltage11 V or more
Throttle position learningCompleted
Either of the following conditions is met:Condition 1 or 2
1. Engine RPMLess than 1,100 rpm
2. Intake air amount per revolution0.22 g/rev or more
TYPICAL MALFUNCTION THRESHOLDS
Purge-cutExcecuting
Either of the following conditions is met:Condition 1 or 2
1. Average between short-term fuel trim and long-term fuel
trim34% or more (varies with ECT)
2. Average between short-term fuel trim and long-term fuel
trim-34% or less (varies with ECT)
WIRING DIAGRAM
Refer to DTC P2195 on page 05-269.
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 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

05-148
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
338 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCs
P0300: Multiple cylinder misfire
P0301: cylinder 1 misfire
P0302: cylinder 2 misfire
P0303: cylinder 3 misfire
P0304: cylinder 4 misfire
Required sensors / components (Main)Injector, ignition coil, spark plug
Required sensors / components (Related)CKP, CMP, ECT, IAT and MAF meter
Frequency of operationContinuous
Duration1,000 revolutions: Emission-related-misfire
200 revolutions: Catalyst-damaged-misfire
MIL operation2 driving cycles (MIL flashes immediately when Catalyst-damaged-misfire occurs)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
Battery voltage8 V or more
Throttle position learningCompleted
VVT systemNot operated by scan tool
Engine RPM400 to 6,200 rpm
All of the following conditions are met:Condition 1 and 2
1. Engine Coolant Temperature (ECT)-10C (14F) or more
2. Either of the following conditions is met:Condition (a) or (b)
(a) ECT at engine startMore than -7C (19.4F)
(b) ECTMore than 20C (68F)
Fuel-cutOFF
Monitor Period of Emission-related-misfire:
First 1,000 revolutions after engine start, or check modeCrankshaft 1,000 revolutions
Except aboveCrankshaft 1,000 revolutions y 4
Monitor Period of Catalyst-damage-misfire (MIL blinks):
All of the following conditions 1, 2 and 3 met:Crankshaft 200 revolutions
1. Driving cycles1st
2. Check ModeOFF
3. Engine RPMLess than 3,800 rpm
Except aboveCrankshaft 200 revolutions x 3
TYPICAL MALFUNCTION THRESHOLDS
Monitor Period of Emission-related-misfire:
Misfire rate4.0 % or more
Monitor Period of Catalyst-damage-misfire (MIL blinks):
Number of misfire per 200 revolutions129 or more (varies with intake air amount and engine RPM)

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-197
387 Author
: Date
:
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.

05-564
- DIAGNOSTICSSFI SYSTEM (3MZ-FE)
754 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)DTC No.
DTC Detection ConditionTrouble Area
P0442
P0455
P0456
Cold engine start.
EVAP VSV has been operated and turned OFF, sealing nega-
tive pressure (vacuum) in system.
ECM begins to monitor fuel tank pressure increase and one
of the following occurs (2 trip detection logic):
(a) Rapid, sharp increase in pressure occurs, indicating small
leak in EVAP system. DTC P0442 is set.
(b) Negative pressure (vacuum) is not strong enough, indicat-
ing large hole in EVAP system. DTC P0455 is set.
(c) Increase in pressure above expected amount occurs, indi-
cating small leak in EVAP system. DTC P0456 is set.
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

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)
05-573
763 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0451 EVAPORATIVE EMISSION CONTROL
SYSTEM PRESSURE SENSOR
RANGE/PERFORMANCE
DTC P0452 EVAPORATIVE EMISSION CONTROL
SYSTEM PRESSURE SENSOR/SWITCH
LOW INPUT
DTC P0453 EVAPORATIVE EMISSION CONTROL
SYSTEM PRESSURE SENSOR/SWITCH
HIGH INPUT
MONITOR DESCRIPTION
DTC ºP0451, P0452 or P0453º is recorded by the ECM when the vapor pressure sensor malfunctions.
P0451
The ECM monitors the vapor pressure sensor in two ways. One method examines the fluctuation of the elec-
trical signal while the engine is idling. If the pressure signal varies beyond the specified range more than 7
times, the ECM interprets this as a fault in the vapor pressure sensor. The ECM also verifies that the pressure
signal changes within the specified range. If the output of the sensor does not vary for 5 minutes while the
intake air amount has been changing, the ECM interprets this as a fault in the vapor pressure sensor. DTC
P0451 will be set when either of the faults occurs and the ECM will turn on the MIL.
P0452 and P0453
When pressure indicated by the vapor pressure sensor deviates below -3.999 kPa (-30 mmHg) or above
1.999 kPa (15 mmHg), the ECM interprets this as a malfunction in the vapor pressure sensor. The ECM will
turn on the MIL and a DTC will be set.
05EXW-05