O2 sensor TOYOTA SEQUOIA 2001 Service Repair Manual

± DIAGNOSTICSENGINE
DI±331
525 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P1442Air switching valve No. 2 (Bank 1) is stuck closed
Related DTCsP1445Air switching valve No. 2 (Bank 2) is stuck closedRelated DTCs
P2441Air switching valve and air switching valve No.2
are stuck closed
Required sensors/componentsPressure sensor, Air switching valve No. 2 (Bank 1, 2), Electromagnetic air switching valve
Frequency of operationContinuous
Duration
P1442 (Air switching valve No. 2 (Bank 1) is stuck closed): 20 sec.
P1445 (Air switching valve No. 2 (Bank 2) is stuck closed): 20 sec.
P2441 (Air switching valve is stuck closed): 8 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
P1442, P1445: Air switching valve No. 2 bank 1 and/or bank 2 are stuck closed
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Atmospheric pressure76 kPa (570 mmHg)±
Battery voltage11.5 V±
IdleON
Engine RPM±3,750 rpm
Time after secondary air injection out of
operation10 sec.±
Air injection pressure sensor failNot detected
P2441: Electromagnetic air switching valve is stuck closed or air switching valve No. 2 (Bank 1 and
Bank 2) are stuck closed
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Atmospheric pressure76 kPa (570 mmHg)±
Battery voltage11.5 V±
Time after secondary air injection in op-
eration6 sec.±
AIR pumpON
Air switching valveON
Air switching valve No. 2 (Bank 1)ON
Air switching valve No. 2 (Bank 2)ON
Engine RPM±3,750 rpm
Delay time after engine started6 sec.±
Air injection pressure sensor failNot detected

DI±344
± DIAGNOSTICSENGINE
538 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
Related DTCsP1613Secondary air injection system control module
range check
Required sensors/componentsAir injection driver
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Case 1:
Battery voltage8 V±
Ignition switchON
StarterOFF
Case 2:
Either of following conditions is metCondition 1 or 2
1. Air pumpNot operating
2. Air switching valveNot operating
Battery voltage8 V±
Ignition switchON
StarterOFF
Case 3:
Air pumpOperating
Air switching valveOperating
Battery voltage8 V±
Ignition switchON
StarterOFF
Case 4:
Battery voltage8 V±
Ignition switchON
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case 1:
One of the following conditions is metCondition 1, 2, 3 or 4
1. Diagnostic signal duty ratio from air injection driver1 to 10 %
2. Diagnostic signal duty ratio from air injection driver30 %
3. Diagnostic signal duty ratio from air injection driver49 %
4. Diagnostic signal duty ratio from air injection driver91 to 99 %
Case 2:
Diagnostic signal duty ratio from air injection driver70 to 90 %

DI±354
± DIAGNOSTICSENGINE
548 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2102 Throttle Actuator Control Motor Circuit Low
DTC P2103 Throttle Actuator Control Motor Circuit High
CIRCUIT DESCRIPTION
The throttle motor is operated by the ECM. It opens and closes the throttle valve.
The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the
throttle body. The throttle position sensor provides feedback to the ECM. This feedback allows the ECM to
control the throttle motor and monitor the throttle opening angle as the ECM responds to driver inputs.
HINT:
This Electrical Throttle Control System (ETCS) does not use a throttle cable.
DTC No.DTC Detection ConditionTrouble Area
P2102
Conditions (a) and (b) continue for 2.0 seconds:
(1 trip detection logic)
(a) Throttle control motor output duty 80 % or more
(b) Throttle control motor current less than 0.5 A or less
Open in throttle control motor and sensor circuit

Throttle control motor and sensor

ECM
P2103
Either of the following condition is met.
(1 trip detection logic)
(a) Throttle control motor current 10 A or more (0.1 sec)
(b) Throttle control motor current 7 A or more (0.6 sec.)
Short in throttle control motor and sensor circuit

Throttle control motor and sensor

Throttle valve

Throttle body

ECM
MONITOR DESCRIPTION
The ECM monitors the current through the electronic throttle motor and detects malfunctions or open circuit
in the throttle motor based on the voltage of the current. When the current deviates from the standard, the
ECM concludes that there is a fault in the throttle motor.
Or, if the throttle valve is not functioning properly (for example, stuck ON), the ECM concludes that there is
a fault, turns on the MIL and sets a DTC is set.
Example:
When the current is more than 10 A. Or the current is less than 0.5 A when the motor driving duty ratio is
exceeding 80%. The ECM concludes that the current is out of range, turns on the MIL and a DTC is set.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel±cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail±safe operation will stop
and the system will return to normal condition.
DICF9±02

± DIAGNOSTICSENGINE
DI±355
549 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
RltdDTC
P2102Throttle actuator control motor current
(Low current)
Related DTCs
P2103Throttle actuator control motor current
(High current)
Required sensors/componentsThrottle actuator motor
Frequency of operationContinuous
Duration2 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
P2102:
Throttle motorON
Duty±cycle ratio to open throttle actuator80%±
Throttle actuator power supply8 V±
Current motor current ± Motor current at
0.016 sec. before±0.2 A
P2103:
Throttle motorON
Either of the following conditions is met:Condition 1 or 2
1. Throttle actuator power supply8 V±
2. Throttle actuator powerON
Battery voltage8 V±
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P2102:
Throttle motor currentLess than 0.5 A (when motor drive duty 80% or more)
P2103:
Throttle motor currentMore than 10 A (0.1 sec.)
More than 7 A (0.6 sec.)
WIRING DIAGRAM
Refer to DTC P0120 on page DI±127.

A21034
T14
Component Side:
M+M± Throttle Control Motor and Sensor
DI±356
± DIAGNOSTICSENGINE
550 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. 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, as well as other
data from the time when a malfunction occurred.
1 Check throttle control motor.
PREPARATION:
Disconnect the throttle control motor and sensor connector.
CHECK:
Measure the resistance between terminals of the throttle con-
trol motor.
OK:
Standard:
Tester ConnectionSpecified Condition
M+ (T14±2) ± M± (T14±1)0.3 to100 W (20°C (68°F))
NG Replace throttle body (See page SF±39).
OK

A21022
T14
M+ M±
Wire Harness Side:
Throttle Control Motor and Sensor
B17412M+
M±
E8ECM Connector
± DIAGNOSTICSENGINE
DI±357
551 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check for open and short in harness and connector between throttle control mo-
tor and ECM.
PREPARATION:
(a) Disconnect the T14 throttle control motor and sensor con-
nector.
(b) Disconnect the E8 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
M+ (T14±2) ± M+ (E8±3)Below 1 W
M± (T14±1) ± M± (E8±2)Below 1 W
M+ (T14±2) or M+ (E8±3) ±
Body ground10 kW or higher
M± (T14±1) or M± (E8±2) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
3 Visually check throttle valve.
CHECK:
Check the area between the throttle valve and the housing for foreign objects.
Also, check if the valve can open and close smoothly.
OK:
The throttle valve is not contaminated by foreign objects and can move smoothly.
NG Remove foreign object and clean throttle body.
OK
Replace ECM (See page SF±80).

DI±358
± DIAGNOSTICSENGINE
552 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2111 Throttle Actuator Control System
±Stuck Open
DTC P2112 Throttle Actuator Control System
±Stuck Closed
CIRCUIT DESCRIPTION
The throttle motor is operated by the ECM. It opens and closes the throttle valve using gears. The opening
angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body.
The throttle position sensor provides feedback to the ECM to control the throttle motor and set the throttle
valve angle in response to driver input.
HINT:
This Electrical Throttle Control System (ETCS) does not use a throttle cable.
DTC No.DTC Detection ConditionTrouble Area
P2111Throttle motor locked during ECM order to close.
(1 trip detection logic)
Throttle control motor and sensor circuit

Throttle control motor and sensor
P2112Throttle motor locked during ECM order to open.
(1 trip detection logic)
Throttle control motor and sensor

Throttle body

Throttle valve
MONITOR DESCRIPTION
The ECM concludes that there is a malfunction of the ETCS (Electronic Throttle Control System) when the
throttle valve remains at a fixed angle despite high drive current from the ECM. The ECM will turn on the MIL
and a DTC is set.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel±cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail±safe operation will stop
and the system will return to normal condition.
DICFA±02

± DIAGNOSTICSENGINE
DI±359
553 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
RltdDTCP2111Throttle motor actuator lock (Open)Related DTCsP2112Throttle motor actuator lock (Closed)
Rid / tMain sensors/componentsThrottle actuator motorRequired sensors/componentsRelated sensors/componentsThrottle position sensor
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
P2111:
Throttle motor current2 A±
Throttle motor duty to close side80%±
P2112:
Throttle motor current2 A±
Throttle motor duty to open side80%±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
|Current throttle position sensor voltage at this time ± throttle
position sensor voltage 0.016 sec. earlier|Less than 0.1 V when throttle motor open (or close) duty 80% or more
WIRING DIAGRAM
Refer to DTC P0120 on page DI±127.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. 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, as well as other
data from the time when a malfunction occurred.

A21034
T14
Component Side:
M+M± Throttle Control Motor and Sensor
A21022
T14
M+ M±
Wire Harness Side:
Throttle Control Motor and Sensor
B17412M+
M±
E8ECM Connector
± DIAGNOSTICSENGINE
DI±361
555 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check throttle control motor.
PREPARATION:
Disconnect the throttle control motor and sensor connector.
CHECK:
Measure the resistance between terminals of the throttle con-
trol motor.
OK:
Standard:
Tester ConnectionSpecified Condition
M+ (T14±2) ± M± (T14±1)0.3 to100 W (20°C (68°F))
NG Replace throttle body (See page SF±39).
OK
4 Check for open and short in harness and connector between ECM and throttle
control motor.
PREPARATION:
(a) Disconnect the T14 throttle control motor and sensor con-
nector.
(b) Disconnect the E8 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
M+ (T14±2) ± M+ (E8±3)Below 1 W
M± (T14±1) ± M± (E8±2)Below 1 W
M+ (T14±2) or M+ (E8±3) ±
Body ground10 kW or higher
M± (T14±1) or M± (E8±2) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Check for intermittent problems
(See page DI±11).

± DIAGNOSTICSENGINE
DI±363
557 Author: Date:
2005 SEQUOIA (RM1146U)
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel±cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail±safe operation will stop
and the system will return to normal condition.
MONITOR STRATEGY
Related DTCsP2118Throttle actuator motor power supply line range
check (Low voltage)
Required sensors/componentsThrottle actuator motor
Frequency of operationContinuous
Duration0.8 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Actuator powerON
Battery voltage8 V±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Throttle actuator motor power supply voltageLess than 4 V
COMPONENT OPERATING RANGE
ParameterStandard Value
Throttle actuator motor power supply voltage9 to 14 V