ESP TOYOTA SEQUOIA 2001 Service User Guide

± DIAGNOSTICSENGINE
DI±85
279 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0016 Crankshaft Position ± Camshaft Position
Correlation (Bank 1 Sensor A)
DTC P0018 Crankshaft Position ± Camshaft Position
Correlation (Bank 2 Sensor A)
CIRCUIT DESCRIPTION
VVT sensor (VVL or VVR signal) consist of a signal plate and pickup coil.
The VVL or VVR signal plate has 1 tooth on its outer circumference and is mounted on the intake camshafts.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The actual camshaft angle is detected by the VVT sensor and it provides feedback to the ECM to control
the intake valve timing in response to during condition.
DTC No.DTC Detecting ConditionTrouble Area
No VVT sensor signal to ECM during cranking at 4 sec. or
more
P0016
P0018No VVT sensor signal to ECM with 5 sec. or more engine
speed 600 rpm or more
Open or short in VVT sensor circuit

VVT sensor

ECMP0018
While the crankshaft rotates twice, VVT sensor signal will be
input to ECM 5 times
ECM
MONITOR DESCRIPTION
The ECM optimizes the valve timing using the VVT (Variable Valve Timing) system to control the intake valve
camshaft. The VVT system includes the ECM, the OCV (Oil Control Valve) and the VVT controller. The ECM
sends a target duty±cycle control signal to the OCV. This control signal, applied to the OCV, regulates the
oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake valve cam-
shaft. The ECM calibrates the valve timing of the VVT system by setting the camshaft to the maximum retard
angle when the engine is idle. The ECM closes the OCV to retard the cam. The ECM stores this value as
VVT learning value (When the difference between the target valve timing and the actual valve timing is 5
degrees or less, the ECM stores this in its memory.).
If the learning value meets both of the following conditions ((a) and (b)), the ECM interprets this as a defect
in the VVT system and sets a DTC.
(a) VVT learning value is less than 20°CA (Crankshaft Angle) or more than 39°CA.
(b) Above condition continues for more than 18 sec.
DIAOO±02

A19755A21037
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
0 5
2.60
2.25
0.97
0.69
Throttle Valve Fully Opened
(Throttle Position expressed as percentage
(VTA1) 64 to 96%)
Fail Safe Angle 7°
(Throttle Position expressed as percentage
(VTA1) about 10 to 24%) Throttle Valve Fully Closed
(Throttle Position expressed as percentage
(VTA1) 10 to 20%)
*1:
VTA1 VTA2 DI±128
± DIAGNOSTICSENGINE
322 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
HINT:

This Electrical 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. 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
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.

A20488A21045
Threshold
(75C (167F))Estimated ECT
5 sec.
Indicated coolant temp. reading
DTC set (after 2 driving cycle) ECT
Time DI±142
± DIAGNOSTICSENGINE
336 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0128 Coolant Thermostat (Coolant Temperature
Below Thermostat Regulating Temperature)
HINT:
This is the purpose of ºthermostatº malfunction detection.
CIRCUIT DESCRIPTION
If the engine coolant temperature does not reach 75°C (167°F) despite sufficient warm±up time has
elapsed.
DTC No.DTC Detection conditionTrouble Area
P0128
Condition (a), (b) and (c) are met:
(a) Cold start
(b) After sufficient warm±up time has elapsed
(c) Engine coolant temperature greater than 75°C (167°F)
Thermostat

Cooling system

Engine coolant temperature sensor

ECM
MONITOR DESCRIPTION
The ECM estimates the coolant temperature based on starting temperature, engine loads, and engine
speeds. The ECM then compares the estimated temperature with the actual ECT (Engine Coolant Tempera-
ture). When the estimated coolant temperature reaches 75C (167F), the ECM checks the actual ECT. If
the actual ECT is less than 75C (167F), the ECM will interpret this as a fault in the thermostat or engine
cooling system and set a DTC.
DICEQ±02

± DIAGNOSTICSENGINE
DI±157
351 Author: Date:
2005 SEQUOIA (RM1146U)
1 Read output DTC.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main switch ON.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand±held tester.
RESULT:
Display (DTC Output)Proceed to
P0138, P0158A
P0137, P0157B
P0136, P0156C
HINT:
If any other codes besides P0136, P0137, P0138, P0156, P0157 and/or P0158 are output, perform the trou-
bleshooting for those DTCs first.
B Go to step 14.
C Go to step 7.
A
2 Check output voltage of heated oxygen sensor.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / O2S B1S2 or B2S2.
(d) Allow the engine to idle.
CHECK:
Read the Heated Oxygen (HO2) sensor output voltage while idling.
RESULT:
HO2 Sensor Output VoltagesProceed To
More than 1.2 VA
Less than 1.0 VB
B Go to step 5.
A

B17391
+12 %
Normal Malfunction±12 %
0 V 3.3 V
1 VA/F Sensor Output
HO2 Sensor OutputInjection Volume
Malfunction
± DIAGNOSTICSENGINE
DI±161
355 Author: Date:
2005 SEQUOIA (RM1146U)
13 Perform active test (injection volume).
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Start the engine and turn the tester ON.
(c) Warm up the engine.
(d) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INJ VOL.
CHECK:
(a) Change the fuel injection volume using the tester, monitoring the voltage output of Air±Fuel Ratio (A/F)
and HO2 sensors displayed on the tester.
HINT:

Change the fuel injection volume within the range of ±12 % and +12 %. The injection volume can be
changed in 1 % graduations within the range.

The A/F sensor is displayed as AFS B1S1 (AFS B2S1), and the HO2 sensor is displayed as O2S B1S2
(O2S B2S2), on hand±held testers.
RESULT:
Tester Display (Sensor)Voltage VariationsProceed To
AFS B1S1 (AFS B2S1) (A/F)Alternates between more and less than 3.3 VOK
AFS B1S1 (AFS B2S1) (A/F)Remains at more than 3.3 VNG
AFS B1S1 (AFS B2S1) (A/F)Remains at less than 3.3 VNG
HINT:
A normal HO2 sensor voltage (O2S B1S2 (O2S B2S2)) reacts in accordance with increases and decreases
in fuel injection volumes. When the A/F sensor voltage remains at either less or more than 3.3 V despite the
HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.
NG Replace air±fuel ratio (A/F) sensor.
OK

A21026
Component Side
C2
Crankshaft Position Sensor
± DIAGNOSTICSENGINE
DI±213
407 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

Read freeze frame data using the hand±held tester. Freeze frame records the engine conditions when
a malfunction is detected. When troubleshooting it is useful for determining whether the vehicle was
running or stopped. the engine was warmed up or not, the air±fuel ratio lean or rich, etc. at the time
of the malfunction.

READ VALUE ON HAND±HELD TESTER
(a) Connect the hand±held tester to the DLC3.
(b) Start the engine and push the hand±held tester tool main switch ON.
(c) When using hand±held tester, enter the following menu: ºDIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / ENGINE SPDº.

The engine speed can be confirmed in DATA LIST using the hand±held tester. If there are no NE sig-
nals from the crankshaft position sensor despite the engine revolving, the engine speed will be indi-
cated as zero. If voltage output of the crankshaft position sensor is insufficient, the engine speed will
be indicated as lower RPM (than the actual RPM).
1 Check resistance of crankshaft position sensor.
PREPARATION:
Disconnect the C2 crankshaft position sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2.
OK:
Standard:
Tester ConnectionSpecified Condition
1 ± 2985 to 1,600 W at cold
1 ± 21,265 to 1,890 W at hot
NOTICE:
º Coldº and ºHotº shown above mean the temperature of
the coils themselves. ºColdº is form ±10°C (14°F) to 50°C
(122°F) and ºHotº is from 50°C (122°F) to 100°C (212°F).
NG Replace crankshaft position sensor.
OK

DI±224
± DIAGNOSTICSENGINE
418 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P0351No. 1 ignition coil with igniter circuit malfunction
P0352No. 2 ignition coil with igniter circuit malfunction
P0353No. 3 ignition coil with igniter circuit malfunction
RltdDTCP0354No. 4 ignition coil with igniter circuit malfunctionRelated DTCsP0355No. 5 ignition coil with igniter circuit malfunction
P0356No. 6 ignition coil with igniter circuit malfunction
P0357No. 7 ignition coil with igniter circuit malfunction
P0358No. 8 ignition coil with igniter circuit malfunction
Required sensors/componentsIgniter
Frequency of operationContinuous
Duration0.256 sec. + 4 sparks
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Engine speed±1,500 rpm
Either of the following conditions is met:Condition 1 or 2
1. Following conditions are met:Condition (a) and (b)
(a) Engine speed±500 rpm
(b) Battery voltage6 V±
2. Following conditions are met:Condition (a) and (b)
(a) Engine speed500 rpm±
(b) Battery voltage10 V±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
ºIgnition signal fail countºMore than 2
ºIgnition signal fail countº is on the right:When IGF does not return despite sending IGT.
COMPONENT OPERATING RANGE
Standard Value
Confirmed signal number = ignition signal number

± DIAGNOSTICSENGINE
DI±235
429 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
The air injection driver (AID) detects an open or short in the circuit according to the voltage of the air pump
terminal (VP) and electromagnetic air switching valve terminal (VV), and sends a signal as diagnostic in-
formation to the ECM.
The AID outputs the air switching valve terminal malfunction signal to the ECM if: 1) VV terminal voltage is
low despite the AID receiving the command signal from the ECM to drive the air switching valve terminal or
2) VV terminal voltage is high despite the AID not receiving the command signal from the ECM.
The ECM stores the DTC based on the diagnostic signal from the AID and illuminates the MIL.
MONITOR STRATEGY
Related DTCsP0412Air switching valve circuit malfunction (Second-
ary air injection system)
Required sensors/componentsAir injection driver, Air switching valve
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:
Air pumpOperating
Air switching valveOperating
Battery voltage8 V±
Ignition switchON
StarterOFF
Case 2:
Air pumpNot operating
Air switching valveNot operating
Battery voltage8 V±
Ignition switchON
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case 1, 2:
Diagnostic signal duty ratio from air injection driver31 to 48 %
COMPONENT OPERATING RANGE
ParameterStandard Value
Diagnostic signal duty ratio from air injection driver
70 to 90% when secondary air injection system operating
and
0% when secondary air injection system not operating

DI±242
± DIAGNOSTICSENGINE
436 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0418 Air Injection System Air Pump Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P0412 on page DI±234.
DTC No.DTC Detection ConditionTrouble Area
P0418
All of the following conditions are met, when idling just after
cold start. (1 trip detection logic):
(a) Air injection system not operate
(b) Air injection driver outputs air pump malfunction signal (20%
duty signal)
Open in air pump drive circuit

Short between air pump circuit and +B circuit

Air injection driver

ECM
P0418
All of the following conditions are met, when idling just after
cold start.
(1 trip detection logic):
(a) Air injection system operates
(b) Air injection driver outputs air pump malfunction signal (20%
duty signal)

Short between air pump circuit and body ground

Air injection driver

ECM
MONITOR DESCRIPTION
Air Injection Driver (AID) detects an open or short in the air pump and Air Switching Valve (ASV) circuit ac-
cording to the terminal voltage and sends a signal as diagnostic information to the ECM.
When the air injection system operation is required while the engine is warming up, the ECM transmits com-
mand signals to the AID to drive the air pump and ASV.
The AID inputs the command signal from ECM if: 1) VP terminal voltage is low despite the AID inputting the
command signal from the ECM to drive the ASV or 2) VP terminal voltage is high despite the AID not inputting
the command signal from the ECM.
The ECM sets the DTC based on the diagnostic information from the AID.
MONITOR STRATEGY
Related DTCsP0418Air pump range check
Required sensors/componentsAir injection driver, Air pump
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate
Sequence of operationNone
DIDMW±01

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