2001 TOYOTA SEQUOIA engine

DI±348
± DIAGNOSTICSENGINE
542 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:

Using the AIR INJ CHECK operation of the SYSTEM CHECK provided in the hand±held tester func-
tion, conditions for air±fuel ratio and pressure in the secondary air injection system passage can be
checked while the secondary air injection system operating. It helps technicians to troubleshoot the
system when it malfunctioning.

Read freeze frame data using a hand±held tester. Freeze frame data record the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle
was moving or stationary, 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 any other DTCs output (In addition to air injection system DTCs).
PREPARATION:
(a) Connect a hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
CHECK:
(a) Read DTCs.
RESULT:
Display (DTC Output)Proceed To
P1613A
P1613 and other DTCsB
HINT:
If any DTCs other than P1613 are output, troubleshoot those DTCs first.
B Go to DTC chart (See page DI±58).
A

B17411
E4
AIDI
± DIAGNOSTICSENGINE
DI±349
543 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check voltage between AIDI terminal of ECM and body ground.
PREPARATION:
(a) Start the engine and warm it up.
(b) Turn the ignition switch to OFF.
(c) Connect a hand±held tester to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
(e) Start the engine.
(f) Select the following menu items: DIAGNOSIS/EN-
HANCED OBD II/SYSTEM CHECK/AIR INJ CHECK/AU-
TOMATIC OPERATION
CHECK:
Measure the voltage between terminal E4±13 (AIDI) of the
ECM connector and body ground when the air injection system
is both ON and OFF.
RESULT:
ResultsSuspected Trouble AreasProceed To
Fixed at Low (1.6 V or less)
even when AI system ON
(Air pump ON, ASV ON)

Short between air pump or air switching valve
command signal circuit and body ground

Open in air pump command signal circuit (be-
tween ECM and AID)

Open in ASV command signal circuit (between
ECM and AID)

Open in AID ground circuit (between AID and
body ground)

Diagnostic signal circuit ground short

AID

ECM
A
Fixed at High (12 V or more)
even when AI system OFF
(Air pump OFF, ASV OFF)

Open in diagnostic signal circuit (ECM ± AID)

Short between +B circuit and diagnostic signal
circuit (ECM ± AID)

Open in AID power source circuit

AID

ECM
B
Other than above:

Fluctuating (duty signal excluding 20, 40,
80%)
AID

Open in AID ground circuit (between AID and
body ground)
C
B Go to step 5.
C Go to step 8.
A

B17411
E4
AIRVAIRP
B17444
Wire Harness Side:
Air Injection Driver Connector
A41
SIPSIVDI E
B17417
E4
AIRP
AIRV DI±350
± DIAGNOSTICSENGINE
544 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check voltage between AIRP, AIRV terminals of ECM and body ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals E4±25 (AIRP), E4±4
(AIRV) of the ECM connector, and body ground.
OK:
Tester ConnectionSpecified Condition
E4±25 (AIRP) ± Body ground10 V or more
E4±4 (AIRV) ± Body ground10 V or more
NG Replace ECM (See page SF±80).
OK
4 Check for short in harness and connector between SIP terminal of air injection
driver and SIRP of ECM.
PREPARATION:
(a) Disconnect the A41 air injection driver connector.
(b) Disconnect the E4 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
SIP (A41±4) or AIRP (E4±25) ±
Body ground10 kW or higher
SIV (A41±3) or AIRV (E4±4) ±
Body ground10 kW or higher
E (A41±1) ± Body groundBelow 1 W
CHECK:
Measure the voltage between terminals DI (A41±2) and E
(A41±1) of the air injection driver wire harness side connectors.
OK:
Standard:
Tester ConnectionSpecified Condition
DI (A41±2) ± E (A41±1)9 V or more

B17444
Wire Harness Side:
Air Injection Driver Connector
A41
+BE
B17444
Wire Harness Side:
Air Injection Driver Connector
A41
DI
± DIAGNOSTICSENGINE
DI±351
545 Author: Date:
2005 SEQUOIA (RM1146U)
NG Repair or replace harness or connector.
OK
Replace air injection driver.
5 Inspect air injection driver power source circuit.
PREPARATION:
(a) Disconnect the A41 air injection driver connector.
(b) Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals +B (A41±5) and E
(A41±1) of the air injection driver connector.
OK:
Standard:
Tester ConnectionSpecified Condition
A41±5 (+B) ± E (A41±1)10 V or more
NG Repair or replace harness or connector.
OK
6 Check voltage between DI terminals of air injection driver and body ground.
PREPARATION:
(a) Disconnect the A41 air injection driver connector.
(b) Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminal A41±2 (DI) of the air in-
jection driver connector and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
A41±2 (DI) ± Body ground10 V or more
NG Go to step 7.
OK

B17444
Wire Harness Side:
Air Injection Driver Connector
A41
DI+B
B17417
E4
AIDI
B17444
Wire Harness Side:
Air Injection Driver Connector
A41
E
DI±352
± DIAGNOSTICSENGINE
546 Author: Date:
2005 SEQUOIA (RM1146U)
7 Check for short in harness and connector between DI terminal of air injection
driver and AIDI terminal of ECM.
PREPARATION:
(a) Disconnect the A41 air injection driver connector.
(b) Disconnect the E4 ECM connector.
CHECK:
Check the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
DI (A41±2) ± AIDI (E4±13)Below 1 W
DI (A41±2) or AIDI (E4±13) ±
+B (A41±5)10 kW or higher
NG Repair or replace harness or connector.
OK
Replace ECM (See page SF±80).
8 Inspect air injection driver ground circuit.
PREPARATION:
Disconnect the A41 air injection driver connector.
CHECK:
Measure the resistance between terminal E (A41±1) of the air
injection driver connector and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
E (A41±1) ± Body ground10 V or more
NG Repair or replace harness or connector.
OK

± DIAGNOSTICSENGINE
DI±353
547 Author: Date:
2005 SEQUOIA (RM1146U)
9 Replace air injection driver.
NEXT
10 Check whether DTC output recurs.
PREPARATION:
(a) Connect a hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Clear the DTCs (see page DI±43).
(d) Start the engine.
CHECK:
(a) Perform SYSTEM CHECK to operate the air injection system.
Select the following menu items: DIAGNOSIS/ENHANCED OBD II/SYSTEM CHECK/AIR INJ
CHECK/AUTOMATIC OPERATION
(b) After operating the secondary air injection system, confirm the pending codes of the secondary air in-
jection system by selecting the following menu items: DIAGNOSIS/ENHANCED OBD II/DTC INFO/
PENDING CODES.
OK:
DTC P1613 for the secondary air injection system is not output.
NG Go to DTC chart (See page DI±58).
OK
END

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.