2001 TOYOTA SEQUOIA engine

DI±84
± DIAGNOSTICSENGINE
278 Author: Date:
2005 SEQUOIA (RM1146U)
7 Check whether or not DTC P0010, P0012, P0021 or P0022 is stored.
PREPARATION:
(a) Clear the DTC (See page DI±43).
(b) Perform simulation test.
CHECK:
Check whether or not DTC P0011, P0012, P0021 or P0022 is stored (See page DI±43).
OK:
Standard: DTC P0011, P0012, P0021 or P0022 is not stored.
OK VVT system is OK.*
*: DTC P0011, P0012, P0021 or P0022 is also output when a
foreign object is detected in some parts of the system in the en-
gine oil, and then the system returns to normal in a short time.
As ECM is controlled to eject a foreign object, there is no prob-
lem on the VVT. There is also no problem on the VVT as the oil
filter should catch the foreign object in the engine oil.
NG
Replace ECM.

± 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

DI±86
± DIAGNOSTICSENGINE
280 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
RltdDTC
P0016Deviation in crankshaft position sensor signal
and camshaft position sensor signal (Bank 1)
Related DTCs
P0018Deviation in crankshaft position sensor signal
and camshaft position sensor signal (Bank 2)
Rid / tC k h ft iti C h ft itiRequired sensors/componentsCrankshaft position sensor, Camshaft position sensor
Frequency of operationOnce per drive cycle
Duration60 sec.
MIL operation2 drive cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Engine RPM400 rpm1,400 rpm
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Duration that either of the following conditions 1 or 2 is met18 sec. or more
1. VVT angle when camshaft is retarded maximumLess than 20CA
2. VVT angle when camshaft is retarded maximumMore than 39CA

A02961
V5
VVT Sensor (Bank 1)ECM
1
2R
G
Y
LVVL+
VVL±
VVR+
E5 18
19
19
18
VVR±
1
2E5
E4
E4 V6
VVT Sensor (Bank 2)
± DIAGNOSTICSENGINE
DI±87
281 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P0016 is displayed, check left bank VVT sensor.

If DTC P0018 is displayed, check right bank VVT sensor.

Read freeze frame data using hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for deter-
mining 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.
1 Check valve timing (Check for loose and jumping teeth of timing belt) (See page
EM±16).
NG Adjust valve timing (Repair or replace timing
belt).
OK
Replace ECM (See page SF±80).

A23512
Reference (Bank 1 Sensor 1 System Drawing):
A/F Sensor A/F Relay
Heater
Sensor
A1A+ HA1A
Duty
Control ECM
From
Battery
A/F Heater
Fuse
A1A±
To EFI Relay DI±88
± DIAGNOSTICSENGINE
282 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0031 Oxygen (A/F) Sensor Heater Control Circuit
Low (Bank 1 Sensor 1)
DTC P0032 Oxygen (A/F) Sensor Heater Control Circuit
High (Bank 1 Sensor 1)
DTC P0051 Oxygen (A/F) Sensor Heater Control Circuit
Low (Bank 2 Sensor 1)
DTC P0052 Oxygen (A/F) Sensor Heater Control Circuit
High (Bank 2 Sensor 1)
HINT:
Although each DTC title (DTC description) says ºoxygen sensorº, these DTCs are related to the ºA/F sensorº.
CIRCUIT DESCRIPTION
Refer to DTC P2195 on page DI±383.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The A/F sen-
sor heater circuit uses a relay on the B+ side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0031
P0051Heated current is 0.8 A or less when heater operates
(1 trip detection logic)
Open or short in heater circuit of A/F sensor

A/F sensor heater
P0032
P0052When the heater operates, heated current exceeds 19.7 A
(1 trip detection logic)
A/F sensor heater

A/F sensor heater relay

ECM
DIDFP±01

± DIAGNOSTICSENGINE
DI±89
283 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:

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

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

Sensor 1 refers to the sensor closest to the engine assembly.

Sensor 2 refers to the sensor farthest away from the engine assembly.
MONITOR DESCRIPTION
The ECM uses the Air±Fuel Ratio sensor (A/F sensor) information to regulate the air±fuel ratio close to the
stoichiometric ratio. This maximizes the catalytic converter's ability to purify exhaust gases. The sensor de-
tects oxygen levels in the exhaust gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The zirconia element generates a small voltage when there is a large difference in
the oxygen concentrations of the exhaust and the outside air. The platinum coating amplifies the voltage
generation. When heated, the sensor becomes very efficient. If the temperature of the exhaust is low, the
sensor will not generate useful voltage signals without supplemental heating. The ECM regulates the sup-
plemental heating using a duty±cycle approach to regulate the average current in the heater element. If the
heater current is out of the normal range, the sensor's output signals will be inaccurate and the ECM can
not regulate the air±fuel ratio properly.
When the heater current is out of the normal operating range, the ECM interprets this as a malfunction and
sets a DTC.
MONITOR STRATEGY
P0031A/F sensor heater (Bank 1) range check (Low
current)
RltdDTC
P0032A/F sensor heater (Bank 1) range check (High
current)
Related DTCs
P0051A/F sensor heater (Bank 2) range check (Low
current)
P0052A/F sensor heater (Bank 2) range check (High
current)
Rid / tMain sensors/componentsA/F sensor heaterRequired sensors/componentsRelated sensors/components±
Frequency of operationContinuous
Duration10 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
P0031, P0051 (Low current):
Battery voltage10.5 V±
A/F sensor heater duty ratio50%±
Time after engine start10 sec.±

B17396
HT +B
AF± AF+ Sensor 1A/F Sensor Component Side:
Front View
DI±90
± DIAGNOSTICSENGINE
284 Author: Date:
2005 SEQUOIA (RM1146U) P0032, P0052 (High current):
Time after engine start10 sec.±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0031, P0051 (Low current):
A/F sensor heater currentLess than 0.8 A
P0032, P0052 (High current):
A/F sensor heater currentMore than 10 A
COMPONENT OPERATING RANGE
ParameterStandard Value
A/F sensor heater current1.8 to 3.4 A at 20°C (68°F)
WIRING DIAGRAM
Refer to DTC P2195 on page DI±383.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using a hand±held tester or OBD II scan tool. 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 resistance of air±fuel ratio (A/F) sensor heater.
PREPARATION:
Disconnect the air±fuel ratio (A/F) sensor connector.
CHECK:
Measure resistance between the terminals of the A/F sensor
connector.
OK:
Standard:
Tester ConnectionSpecified Condition
HT (1) ± +B (2)1.8 W to 3.4 W at 20C (68F)
HT (1) ± AF± (4)10 kW or higher
NG Replace air±fuel ratio (A/F) sensor.
OK

A19288
B17411
HA1A
E7HA2A
± DIAGNOSTICSENGINE
DI±91
285 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check A/F relay.
PREPARATION:
Remove the A/F relay from the engine room R/B No.2.
CHECK:
Inspect the A/F relay.
OK:
Standard:
Terminal No.ConditionSpecified Condition
3 ± 5Always10 KW or higher
3 ± 5Apply B+ between
terminals 1 and 2Below 1 W
NG Replace A/F relay.
OK
3 Check voltage between terminals HA1A, HA2A of ECM connectors and body
ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals of the ECM connectors
and body ground.
HINT:

Connect terminal HA1A to the bank 1 sensor 1.

Connect terminal HA2A to the bank 2 sensor 1.
OK:
Standard:
Tester ConnectionSpecified Condition
HA1A (E7±2) ± Body ground9 V to 14 V
HA2A (E7±1) ± Body ground9 V to 14 V
OK Replace ECM (See page SF±80).
NG