o2 sensor TOYOTA HIGHLANDER 2001 Service Repair Manual

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-91
281 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
The ECM monitors the sensor voltage and uses this value to calculate the intake air temperature. When the
sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the IAT
sensor and sets a DTC.
Example:
The sensor voltage output is -40C (-40F), or more than 140C (284F) and either condition continues
for 0.5 seconds or more.
MONITOR STRATEGY
Related DTCs
P0110: IAT sensor range check (Chattering)
P0112: IAT sensor range check (Low Resistance)
P0113: IAT sensor range check (High Resistance)
Required sensors / components (Main)IAT sensor
Required sensors / components (Related)-
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-16
TYPICAL MALFUNCTION THRESHOLDS
P0110:
IAT sensor resistanceLess than 98.5 W, or more than 156 kW
P0112:
IAT sensor resistance [IAT]Less than 98.5 W [More than 140C (284F)]
P0113:
IAT sensor resistance [IAT]More than 156 kW [-40C (-40F)]
COMPONENT OPERATING RANGE
IAT sensor resistance [IAT]98.5 W to 156 kW [-39 to 140C (-40 to 284F)]

A90293
M1
MAF Meter
(IAT Sensor)ECM
4
5E2THA5 V
E7
E720
28 L-B
BR G
BR
S28S29 5
5 Short
Connector
05-92
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
282 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs that are related to different systems are output simultaneously while terminal E2 is used as
a ground terminal, terminal E2 may have an open 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.
1 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (INTAKE AIR
TEMPERATURE)
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Turn ON the ignition switch. Push the hand-held tester or the OBD II scan tool main switch ON.
(c) On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED
OBD II / DATA LIST / ALL / INTAKE AIR. Read the values.
Temperature: The same as actual intake air temperature.
Result:
DisplayProceed to
-40°C (-40°F)A
140°C (284°F) or moreB
OK (same as present temperature)C
HINT:

If there is an open circuit, the hand-held tester or the OBD II scan tool indicates -40°C (-40°F).

If there is a short circuit, the hand-held tester or the OBD II scan tool indicates 140°C (284°F) or more.
B Go to step 4
C CHECK FOR INTERMITTENT PROBLEMS
(See page 05-9)
A

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-95
285 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0115 ENGINE COOLANT TEMPERATURE CIRCUIT
DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT
LOW INPUT
DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT
HIGH INPUT
CIRCUIT DESCRIPTION
A thermistor is built into the Engine Coolant Temperature (ECT) sensor and changes the resistance value
according to the engine coolant temperature.
The structure of the sensor and connection to the ECM are the same as the Intake Air Temperature (IAT)
sensor.
HINT:
If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe function in which the ECT is
assumed to be 80C (176F).
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0115Step 1
Open or short in ECT (En-
gine coolant temperature)
sensor circuit for 0.5 se-
conds
Open or short in ECT sensor circuit

ECT sensor

ECM
P0117Step 4Short in ECT sensor circuit
for 0.5 seconds
Same as DTC No. P0115
P0118Step 2Open in ECT sensor circuit
for 0.5 seconds
Same as DTC No. P0115
HINT:
After confirming DTC P0115, P0117 or P0118, use the hand-held tester or the OBD II scan tool to confirm
the ECT from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL).
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
MONITOR DESCRIPTION
The ECT sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor that
varies its resistance depending on the temperature of the engine coolant. When the coolant temperature
is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The
variations in resistance are reflected in the voltage output from the sensor.
The ECM monitors the sensor voltage and uses this value to calculate the engine coolant temperature.
When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault
in the ECT sensor and sets a DTC.
Example:
When the ECM calculates that the ECT is -40C (-40F) or more than 140C (284F) and if either condition
continues for 0.5 seconds or more, the ECM will set a DTC.
0596C-07

A90294
ECM
THW
E2
1 2 E2
ECT Sensor
5 V
R
THW
E2
E7 E7 19
28
BRG-B
BRBR
S28S29 5
5 Short
Connector 05-96
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
286 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCs
P0115: ECT sensor range check (Chattering)
P0117: ECT sensor range check (Low resistance)
P0118: ECT sensor range check (High resistance)
Required sensors / components (Main)ECT sensor
Required sensors / components (Related)-
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-16
TYPICAL MALFUNCTION THRESHOLDS
P0115:
ECT sensor resistanceLess than 79 W or more than 156 kW
P0117:
ECT sensor resistance [ECT]Less than 79 W [More than 140C (284F)]
P0118:
ECT sensor resistance [ECT]More than 156 kW [-40C (-40F)]
COMPONENT OPERATING RANGE
ECT sensor resistance [ECT]79 W to 156 KW [-39 to 140C (-40 to 284F)]
WIRING DIAGRAM

Y
75743
A66104A85509
E2
ECT SensorECM
THW
E2
Wire Harness Side
E2
ECT Sensor
Y
A75742
A76903A85507
ECM
THW
E2
E7
ECM THW
E2E2
ECT Sensor
05-98
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
288 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR
OPEN IN WIRE HARNESS)
(a) Disconnect the E2 ECT sensor connector.
(b) Connect terminals 1 and 2 of the E2 ECT sensor wire har-
ness side connector.
(c) Turn the ignition switch ON.
(d) On the hand-held tester or the OBD II scan tool, enter the
following menus: DIAGNOSIS / ENHANCED OBD II /
DATA LIST / ALL / COOLANT TEMP. Read the values.
OK:
Temperature value: 1405C (2845F) or more
OK CONFIRM GOOD CONNECTION AT SENSOR. IF
OK, REPLACE ENGINE COOLANT TEMP.
SENSOR
NG
3 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR
OPEN IN ECM)
(a) Disconnect the E2 ECT sensor connector.
(b) Connect terminals THW and E2 of the E7 ECM connector.
HINT:
Before checking, do a visual and contact pressure check for the
ECM connector.
(c) Turn the ignition switch ON.
(d) On the hand-held tester or the OBD II scan tool, enter the
following menus: DIAGNOSIS / ENHANCED OBD II /
DATA LIST / ALL / COOLANT TEMP. Read the values.
OK:
Temperature value: 1405C (2845F) or more
OK REPAIR OR REPLACE HARNESS AND
CONNECTOR
NG

A75766
E2
ECT SensorECM
THW
E2
Y
A75744
A81699A85508
ECM
THW
E2
E7
ECM E2
ECT Sensor
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-99
289 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM (See page 10-9)
4 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR
SHORT IN WIRE HARNESS)
(a) Disconnect the E2 ECT sensor connector.
(b) Turn the ignition switch ON.
(c) On the hand-held tester or the OBD II scan tool, enter the
following menus: DIAGNOSIS / ENHANCED OBD II /
DATA LIST / ALL / COOLANT TEMP. Read the values.
OK:
Temperature value: -405C (-405F)
OK REPLACE ENGINE COOLANT TEMPERATURE
SENSOR
NG
5 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR
SHORT IN ECM)
(a) Disconnect the E7 ECM connector.
(b) Turn the ignition switch ON.
(c) On the hand-held tester or the OBD II scan tool, enter the
following menus: DIAGNOSIS / ENHANCED OBD II /
DATA LIST / ALL / COOLANT TEMP. Read the values.
OK:
Temperature value: -405C (-405F)
OK REPAIR OR REPLACE HARNESS AND
CONNECTOR
NG
REPLACE ECM (See page 10-9)

05-100
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
290 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0116 ENGINE COOLANT TEMP. CIRCUIT
RANGE/PERFORMANCE PROBLEM
CIRCUIT DESCRIPTION
Refer to DTC P0115 on page 05-95.
DTC No.DTC Detection ConditionTrouble Area
P0116
ECT is between 35°C (95°F) and 60°C (140°F) when engine
is started, and conditions (a) and (b) are met:
(a) Vehicle has accelerated and decelerated
(b) ECT remains within 3°C (5.4°F) of initial engine coolant
temperature
(2 trip detection logic)

Cooling system

ECT sensor
ECT is more than 60°C (140°F) when engine is started and
vehicle has accelerated and decelerated

ECT sensor records a temperature variation is within 1°C
(1.8°F) successively 6 times
(6 trip detection logic)
ECT sensor
MONITOR DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is used to monitor the engine coolant temperature. The ECT
sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When
the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the
resistance drops. The variations in resistance are reflected in the voltage output from the sensor. The ECM
monitors the sensor voltage and uses this value to calculate the engine coolant temperature. When the sen-
sor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT
sensor and sets a DTC.
Examples:
1) Upon starting the engine, the ECT is between 35C (95F) and 60C (140F). If, after driving for 250 se-
conds, the ECT still remains within 3C (5.4F) of the starting temperature, a DTC will be set (2 trip detection
logic).
2) Upon starting the engine, the ECT is over 60C (140F). If, after driving for 250 seconds, the ECT still
remains within 1C (1.8F) of the starting temperature, a DTC will be set (6 trip detection logic).
MONITOR STRATEGY
Related DTCsP0116: ECT sensor stuck
P0116: ECT sensor stuck at high
Required sensors / components (Main)ECT sensor
Required sensors / components (Related)CKP sensor, IAT sensor, MAF meter
Frequency of operationContinuous
Duration250 sec. or more
MIL operation2 driving cycles: ECT sensor stuck
6 driving cycles: ECT sensor stuck at high
Sequence of operationNone
051ZP-14

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-101
291 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TYPICAL ENABLING CONDITIONS
The monitor will run whenever this DTC is not presentSee page 05-16
ECT Sensor Stuck at Low ECT:
Cumulative idle off period250 sec. or more
Speed increase by 30 km/h (18.6 mph) or more10 times or more
ECT35 to 60C (95 to 140F)
IAT-6.7C (20F) or more
ECT Sensor Stuck at High ECT:
ECT60C (140F) or more
IAT-6.7C (20F) or more
ºStop and goº*1Once or more
ºSteady driving and stop*2Once or more
*1 Vehicle is stopped for 20 seconds or more and accelerated to more than 43.5 mph (70 km/h) within 40
seconds.
*
2 Vehicle is driven by 40.4 mph (65 km/h) or more for 30 seconds or more and the vehicle speed reaches
43.5 mph (70 km/h). The vehicle is decelerated from 40.4 mph (65 km/h) to 1.86 mph (3 km/h) or less within
35 seconds and stopped for 10 seconds.
TYPICAL MALFUNCTION THRESHOLDS
ECT Sensor Stuck at Low ECT:
ECT changeLess than 3C (5.4F)
ECT sensor Stuck at High ECT:
ECT change1C (1.8F) or less
COMPONENT OPERATING RANGE
ECTVaries with actual ECT (Engine coolant temperature)
INSPECTION PROCEDURE
HINT:

If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, the ECT sensor circuit
may be open or shorted. Perform the troubleshooting of DTC P0115, P0117 or P0118 first.

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.
REPLACE ENGINE COOLANT TEMPERATURE SENSOR

05-102
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
292 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0120 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT
DTC P0122 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT LOW INPUT
DTC P0123 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT HIGH INPUT
DTC P0220 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºBº CIRCUIT
DTC P0223 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºBº CIRCUIT HIGH INPUT
DTC P2135 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº/ºBº VOLTAGE
CORRELATION
0596D-07

A19755A19802
Throttle Position Sensor ECM
Magnet
Magnet
IC No. 2 IC No. 1
VC
VTA1
E2 VTA2Throttle Position Sensor Output Voltage (V)
Fail-safe Angle
*1
Usable Range
Throttle Valve Opening Angle (deg.)84 6.5
0 5
2.58
2.25
0.95
0.69
Throttle Valve Fully Opened
(Throttle Position expressed as percentage
(VTA1) 64 to 96 %)
Fail-safe Angle 6.5°
(Throttle Position expressed as percentage
(VTA1) about 16 %) Throttle Valve Fully Closed
(Throttle Position expressed as percentage
(VTA1) 10 to 24 %)
*
1:
VTA1 VTA2
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-103
293 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
CIRCUIT DESCRIPTION
HINT:

This Electronic Throttle Control System (ETCS) does not use a throttle cable.

This throttle position sensor is a non-contact type.
The throttle position sensor is mounted on the throttle body and it detects the opening angle of the throttle
valve. This sensor is electronically controlled and uses Hall-effect elements, so that accurate control and
reliability can be obtained. The throttle position sensor has 2 sensor elements/signal outputs: VTA1 and
VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA1.
Voltage applied to VTA1 and VTA2 change between 0 V and 5 V in proportion to the opening angle of the
throttle valve. There are several checks that the ECM performs to confirm proper operation of the throttle
position sensor and VTA1.
The ECM judges the current opening angle of the throttle valve from these signals input from terminals VTA1
and VTA2, and the ECM controls the throttle motor to make the throttle valve angle properly in response to
driver inputs.