2001 TOYOTA SEQUOIA ESP

DI±74
± DIAGNOSTICSENGINE
268 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
After the ECM sends the ºtargetº duty±cycle signal to the OCV (Oil Control Valve), the ECM monitors the
OCV current to establish an ºactualº duty±cycle. When the actual duty±cycle ratio varies from the target
duty±cycle, the ECM sets a DTC.
MONITOR STRATEGY
RltdDTCP0010VVT oil control valve bank 1 range checkRelated DTCsP0020VVT oil control valve bank 2 range check
Required sensors/componentsOCV
Frequency of operationContinuous
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Battery voltage11 V13 V
Target duty ratio±70%
StarterOFF
Current cut statusNot cut
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Either of the following conditions is met:Condition 1 or 2
1. Output signal duty for OCVOutput duty ratio is 100% (always ON) but target duty ratio is less than 70%
2. Output signal duty for OCVOutput duty is 3% or less despite the ECM supplying current to the OCV
COMPONENT OPERATING RANGE
ParameterStandard Value
Output signal duty for OCVºMore than 3%º and ºless than 100%º

DI±80
± DIAGNOSTICSENGINE
274 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P0011VVT system advance (Bank 1)
RltdDTCP0012VVT system retard (Bank 1)Related DTCsP0021VVT system advance (Bank 2)
P0022VVT system retard (Bank 2)
Main sensors/componentsCamshaft position sensor
Required sensors/componentsRelated sensors/componentsEngine coolant temperature sensor,
Crankshaft position sensor
Frequency of operationOnce per drive cycle
Duration10 sec.
MIL operationP0011, P0021: Immediate
P0012, P0022: 2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage11 V±
Throttle position learningCompleted
Engine RPM400 rpm4,000 rpm
Engine coolant temperature75C (167F)100C (212F)
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Deviation of valve timingMore than 5CA
OCV activation63 times or more
Response of valve timing1 sec./1CA or more
WIRING DIAGRAM
Refer to DTCs P0010 on page DI±73.
INSPECTION PROCEDURE
HINT:

Bank 1 refers to bank that includes cylinder No. 1.

Bank 2 refers to bank that does not include cylinder No. 1.

If DTC P0011, P0012 is displayed, check the bank 1 VVT system.

If DTC P0021, P0022 is displayed, check the bank 2 VVT system.

Read freeze frame data using the hand±held tester. Freeze frame data 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 was lean or rich, etc. at
the time of the malfunction.

± 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