2001 TOYOTA HIGHLANDER heating

'05 HIGHLANDER_U (L/O 0409)
252
2005 HIGHLANDER from Nov. '04 Prod. (OM48570U)

If following another vehicle on a dusty
road, or driving in windy and dusty
conditions, it is recommended that the
air intake selector be temporarily set to
RECIRCULATE, which will close off the
outside passage and prevent outside
air and dust from entering the vehicle
interior.Heating
For best results, set controls to:
Fan speedÐAny setting except OFFº
TemperatureÐTo w a r d s WARM
(red zone)
Air intakeÐFRESH (outside air)
Air flowÐFLOOR
Air conditioningÐOFF

For quick heating, select recirculated
air for a few minutes. To keep the
windows from fogging, select fresh af-
ter the vehicle interior has been
warmed.

Press the A/Cº button on for dehumidi-
fied heating.

Choose floor/windshield air flow to heat
the vehicle interior while defrosting or
defogging the windshield.
Air conditioning
For best results, set controls to:
Fan speedÐAny setting except OFFº
TemperatureÐTo w a r d s COLD
(blue zone)
Air intakeÐFRESH (outside air)
Air flowÐPANEL
Air conditioningÐON

For quick cooling, turn the temperature
selector knob fully towards COLD and
change the air intake selector mode to
RECIRCULATE.

'05 HIGHLANDER_U (L/O 0409)
258
2005 HIGHLANDER from Nov. '04 Prod. (OM48570U)

If following another vehicle on a dusty
road, or driving in windy and dusty
conditions, it is recommended that the
air intake selector be temporarily set to
RECIRCULATE, which will close off the
outside passage and prevent outside
air and dust from entering the vehicle
interior.Heating
For best results, set controls to:
For automatic operationÐ
Press in the AUTOº button.
TemperatureÐTo the desired
temperature
Air intakeÐFRESH (outside air)
Air conditioningÐOFF
For manual operationÐ
Fan speedÐTo the desired fan speed
TemperatureÐTo w a r d s WARM
(to the right)
Air intakeÐFRESH (outside air)
Air flowÐFLOOR
Air conditioningÐOFF

For quick heating, select recirculated
air for a few minutes. To keep the
windows from fogging, select fresh af-
ter the vehicle interior has been
warmed.

Press the A/Cº button on for dehumidi-
fied heating.

Choose floor/windshield air flow to heat
the vehicle interior while defrosting or
defogging the windshield.Air conditioning
For best results, set controls to:
For automatic operationÐ
Press in the AUTOº button.
TemperatureÐTo the desired
temperature
Air intakeÐFRESH (outside air)
Air conditioningÐON
For manual operationÐ
Fan speedÐTo the desired fan speed
TemperatureÐTo w a r d s COLD
(to the left)
Air intakeÐFRESH (outside air)
Air flowÐPANEL
Air conditioningÐON

For quick cooling, select recirculated
air for a few minutes.

'05 HIGHLANDER_U (L/O 0409)
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2005 HIGHLANDER from Nov. '04 Prod. (OM48570U)
CAUTION
When doing the circling calibration,
be sure to secure a wide space,
and watch out for people and ve-
hicles in the neighborhood. Do not
violate any local traffic rules while
performing circling calibration.
Do not adjust the display while the
vehicle is moving. Be sure to adjust
the display only when the vehicle is
stopped.
Cigarette lighter
Front ashtray
Rear ashtray
CIGARETTE LIGHTER
To use the cigarette lighter, press it in.
After it finishes heating up, it automati-
cally pops out ready for use.
If the engine is not running, the key must
be in the ACCº position.
Do not hold the cigarette lighter pressed
in.
Use a Toyota genuine cigarette lighter or
equivalent for replacement.
Cigarette lighter and ashtrays

05-72
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
262 Author
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:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
The ECM uses A/F sensor information to keep the air/fuel ratio close to the stoichiometric ratio. This maxi-
mizes the catalytic converter's ability to purify exhaust gas. The sensor detects oxygen levels in the exhaust
gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The zirconia element generates small voltage when there is a large difference in
the oxygen concentrations of the exhaust and the outside air. The platinum coating amplifies the voltage
generation. When heated, the sensor becomes very efficient. If the temperature of the exhaust is low, the
sensor will not generate useful voltage signals without supplemental heating. The ECM regulates the sup-
plemental heating using a duty-cycle approach to regulate the average current in the heater element. If the
heater current is out of the normal range, the sensor's output signals will be inaccurate and the ECM cannot
regulate the A/F ratio properly.
When the heater current is out of the normal operating range, the ECM interprets this as a malfunction and
sets a DTC.
MONITOR STRATEGY
Related DTCsP0031: A/F sensor heater range check (Low current)
P0032: A/F sensor heater range check (High current)
Required sensors / components (Main)A/F sensor heater
Required sensors / components (Related)-
Frequency of operationContinuous
Duration10 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
P0031:
Battery voltageLess than 10.5 V
A/F sensor heater duty ratio50 % or more
Time after engine start10 sec. or more
P0032:
Time after engine start10 sec. or more
TYPICAL MALFUNCTION THRESHOLDS
P0031:
A/F sensor heater currentLess than 0.8 A
P0032:
A/F sensor heater currentMore than 10 A
COMPONENT OPERATING RANGE
A/F sensor heater current1.8 to 3.4 A at 20°C (68°F)

A90346
Reference
Heater
Sensor
Duty
Control ECM
From
Battery
EFI NO. 1
FuseEFI Relay
+B HT
EFI NO. 2
Fuse
MREL OX1B HT1B Heated Oxygen Sensor
OB1- OX E1 05-76
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
266 Author
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:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0037 OXYGEN SENSOR HEATER CONTROL
CIRCUIT LOW (BANK 1 SENSOR 2)
DTC P0038 OXYGEN SENSOR HEATER CONTROL
CIRCUIT HIGH (BANK 1 SENSOR 2)
CIRCUIT DESCRIPTION
Refer to DTC P0136 on page 05-1 18.
HINT:
The ECM provides a pulse width a modulated control circuit to adjust current through the heater. The oxygen
sensor heater circuit uses a relay on the +B side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0037
Heater current of less than 0.3 A when the heater operates
with +B greater than 10.5 V
(1 trip detection logic)
Open or short in heater circuit of heated oxygen sensor

Heated oxygen sensor heater

EFI relay

ECM
P0038Heater current exceeds 2 A when heater operates
(1 trip detection logic)
Same as DTC No. P0037
HINT:
Sensor 2 is the sensor farthest away from the engine assembly.
MONITOR DESCRIPTION
The sensing portion of the heated oxygen sensor has a zirconia element that is used to detect oxygen con-
centration in the exhaust. If the zirconia element is at the proper temperature and the difference of the oxy-
gen concentration between the inside and outside surface of the sensor is large, the zirconia element will
generate voltage signals. In order to increase the oxygen concentration detecting capacity in the zirconia
element, the ECM supplements the heat from the exhaust with heat from a heating element inside the sen-
sor. When current in the sensor is out of the standard operating range, the ECM interprets this as a fault in
the heated oxygen sensor and sets a DTC.
Example:
The ECM will set a high current DTC if the current in the sensor is more than 2 A when the heater is OFF.
Similarly, the ECM will set a low current DTC if the current is less than 0.25 A when the heater is ON.
05ETE-05

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-77
267 Author
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:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCsP0037: HO2S heater range check (Low current)
P0038: HO2S heater range check (High current)
Required sensors / components (Main)Heated oxygen sensor (HO2S) heater
Required sensors / components (Related)Vehicle speed sensor (VSS)
Frequency of operationContinuous
Duration0.3 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
P0037:
Battery voltage10.5 V or more
EngineRunning
StarterOFF
Intrusive heatingNot operated
P0038 (Case 1):
Battery voltage10.5 V or more
EngineRunning
StarterOFF
Intrusive heatingNot operated
P0038 (Case 2):
Battery voltage10.5 V or more
All heater is turned OFF and intrusive heating is operated
when the following conditions are metCondition 1 and 2
1. HeaterON
2. Heater current2 A or more
TYPICAL MALFUNCTION THRESHOLDS
P0037:
HO2S heater current intrusive heatingLess than 0.3 A
P0038 (Case 1):
HO2S heater current2 A or more
P0038 (Case 2):
HO2S heater current intrusive heatingMore than 2 A
COMPONENT OPERATING RANGE
HO2S heater current0.4 to 1 A (when engine is idle, warmed-up and battery voltage is 11 to 14 V)

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
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

2005 HIGHLANDER (EWD592U)
18
E GLOSSARY OF TERMS AND SYMBOLS
BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.GROUND
The point at which wiring attaches to
the Body, thereby providing a return
path for an electrical circuit; without a
ground, current cannot flow.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.HEADLIGHTS
Current flow causes a headlight
filament to heat up and emit light. A
headlight may have either a single
(1) filament or a double (2) filament
1. SINGLE
FILAMENT
CIGARETTE LIGHTER
An electric resistance heating
element.2. DOUBLE
FILAMENT
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it.
Some units automatically reset when
cool, others must be manually reset.HORN
An electric device which sounds a
loud audible signal.
DIODE
A semiconductor which allows
current flow in only one direction.IGNITION COIL
Converts low-voltage DC current
into high-voltage ignition current for
firing the spark plugs.
DIODE, ZENERA diode which allows current flow in one
direction but blocks reverse flow only up
to a specific voltage. Above that potential,
it passes the excess voltage. This acts as
a simple voltage regulator.LIGHT
Current flow through a filament
causes the filament to heat up and
emit light.
PHOTODIODE
The photodiode is a semiconductor
which controls the current flow
according to the amount of light.LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes emit
light without producing the heat of a
comparable light.
DISTRIBUTOR, IIA
Channels high-voltage current from
the ignition coil to the individual
spark plugs.METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to move,
thereby providing a relative display
against a background calibration.
FUSEA thin metal strip which burns through
when too much current flows through it,
thereby stopping current flow and
protecting a circuit from damage.
FUSIBLE LINK
METER, DIGITAL
Current flow activates one or many
LED's, LCD's, or fluorescent
displays, which provide a relative or
digital display.
FUEL
FUSIBLE LINK
A heavy-gauge wire placed in high
amperage circuits which burns through on
overloads, thereby protecting the circuit.
The numbers indicate the crosssection
surface area of the wires.(for Medium Current Fuse)
(for High Current Fuse or
Fusible Link)MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion.
M