2001 TOYOTA SEQUOIA change time

± DIAGNOSTICSENGINE
DI±261
455 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
Purge VSV stuck open
Related DTCsP0441Purge VSV stuck closedRelated DTCsP0441
Purge flow
Required sensors/componentsPurge VSV, Pump module
Frequency of operationOnce per driving cycle
DurationPurge VSV stuck open and closed: Within 2 min. (varies with amount of fuel in tank)
Purge flow: Within 30 sec.
MIL operation2 driving cycle
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Purge VSV stuck open and closed:
Following values are when atmospheric is
760 mmHg (100 kPa)±
EVAP key±off monitor runs when all of the
following conditions met:±
Atmospheric pressure525 to 825 mmHg (70 to 110 kPa)
Battery voltage10.5 V±
Vehicle speed±4 km/h (2.5 mph)
Ignition switchOFF
Engine conditionNot running
Time after engine stopped5 hours
FTP sensor malfunction (P0450, P0452,
P0453)Not detected
Purge VSVNot operated by scan tool
Vent valveNot operated by scan tool
Leak detection pumpNot operated by scan tool
Both of the following conditions are met
before IG switch OFFCondition 1 and 2
1. Duration that vehicle is driven5 min.±
2. Purge flowExecuted
ECT4.4 to 35°C (40 to 95°F)
IAT4.4 to 35°C (40 to 95°F)
Example of re±start time±
First time7 hours
Second time9 hours and 30 min.
Key±off monitor sequence1 to 8
1. Atmospheric pressure±
Next sequence is run if following condition
set±
Atmospheric pressure change for 10 sec.±2.25 mmHg (0.3 kPa) for 1 sec.
2. First reference pressure±

DI±262
± DIAGNOSTICSENGINE
456 Author: Date:
2005 SEQUOIA (RM1146U) Next sequence is run if all of following
conditions set
Condition 1, 2 and 3
1. FTP when 4 sec. after reference pres-
sure measurement±±7.5 mmHg (±1 kPa)
2. Reference pressure±36.38 to ±7.93 mmHg (±4.85 to ±1057 kPa)
3. Reference pressureSaturated
3. Vent valve stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after vent valve
ON (closed)2.25 mmHg (0.3 kPa)±
4. Vacuum introduction and leak±
Next sequence is run if both of following
conditions setCondition 1 and 2
1. Vacuum introduction time±15 min.
2. FTPFTP was saturated
5. Purge VSV stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after purge VSV
ON (open)2.25 mmHg (0.3 kPa)±
6. Second reference pressure measure-
ment±
Next sequence is run if all of following
conditions setCondition 1, 2, 3 and 4
1. FTP when 4 sec. after reference pres-
sure measurement±±7.5 mmHg (±1 kPa)
2. Reference pressure±36.38 to ±7.93 mmHg (±4.85 to ±1057 kPa)
3. Reference pressureSaturated
4. Reference pressure difference between
first and second±5.25 mmHg (0.7 kPa)
7. Leak check±
Next sequence is run if following condition
set±
FTP when vacuum introduction was com-
plete±Second reference pressure
8. Atmospheric pressure±
Monitor is complete if following±
Atmospheric pressure difference between
sequence 1 and 8±2.25 mmHg (0.3 kPa)
Purge flow:
Engine conditionRunning
ECT4.4°C (40°F)±
IAT4.4°C (40°F)±
FTP sensor malfunctionNot detected
Purge VSVNot operated by scan tool
EVAP system checkNot operated by scan tool

± DIAGNOSTICSENGINE
DI±267
461 Author: Date:
2005 SEQUOIA (RM1146U) Pressure sensor chattering, low/high voltage:
Battery voltage8 V±
Ignition switchON
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Pressure sensor noise:
Frequency that FTP change is 0.3 kPa or more10 times or more for 10 sec.
Pressure sensor stuck:
FTP change for 10 sec. during EVAP monitor (0.02 inch
reference pressure)Less than 4.9 mmHg (0.65 kPa)
Pressure sensor chattering:
Pressure sensor voltageLess than 0.45 V, or more than 4.9 V
Pressure sensor low voltage:
Pressure sensor voltageLess than 0.45 V
Pressure sensor high voltage:
Pressure sensor voltageMore than 4.9 V

DI±276
± DIAGNOSTICSENGINE
470 Author: Date:
2005 SEQUOIA (RM1146U) Atmospheric pressure
525 to 825 mmHg (70 to 110 kPa)
Battery voltage10.5 V±
Vehicle speed±4 km/h (2.5 mph)
Ignition switchOFF
Engine conditionNot running
Time after engine stopped5 hours
FTP sensor malfunction (P0450, P0452,
P0453)Not detected
Purge VSVNot operated by scan tool
Vent valveNot operated by scan tool
Leak detection pumpNot operated by scan tool
Both of the following conditions are met
before IG switch OFFCondition 1 and 2
1. Duration that vehicle is driven5 min.±
2. Purge flowExecuted
ECT4.4 to 35°C (40 to 95°F)
IAT4.4 to 35°C (40 to 95°F)
Example of re±start time±
First time7 hours
Second time9 hours and 30 min.
Key±off monitor sequence1 to 8
1. Atmospheric pressure±
Next sequence is run if following condition
set±
Atmospheric pressure change for 10 sec.±2.25 mmHg (0.3 kPa) for 1 sec.
2. First reference pressure±
Next sequence is run if all of following
conditions setCondition 1, 2 and 3
1. FTP when 4 sec. after reference pres-
sure measurement±±7.5 mmHg (±1 kPa)
2. Reference pressure±36.38 to ±7.93 mmHg (±4.85 to ±1.057 kPa)
3. Reference pressureSaturated
3. Vent valve stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after vent valve
ON (closed)2.25 mmHg (0.3 kPa)±
4. Vacuum introduction and leak±
Next sequence is run if both of following
conditions setCondition 1 and 2
1. Vacuum introduction time±15 min.
2. FTPFTP was saturated
5. Purge VSV stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after purge VSV
ON (open)2.25 mmHg (0.3 kPa)±

DI±318
± DIAGNOSTICSENGINE
512 Author: Date:
2005 SEQUOIA (RM1146U) Air switching valve
ON
Engine RPM±3,750 rpm
P2440: Electromagnetic air switching valve and air switching valve No. 2 are stuck open
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 out of
operation10 sec.±
Cumulative intake air amount172 g±
AIR pumpOFF
Air switching valveOFF
Air switching valve No. 2 (Bank 1)OFF
Air switching valve No. 2 (Bank 2)OFF
Engine RPM±3,750 rpm
Air injection pressure sensor failNot detected
TYPICAL MALFUNCTION THRESHOLDS
P1441, P1444: Air switching valve No. 2 bank 1 and/or bank 2 are stuck open
Detection CriteriaThreshold
CASE 1:
Both of the following conditions are metCondition (a) and (b)
(a) Cumulative pressure pulsation (When AI OFF)20 kPa (150 mmHg) or more
(b) Air pressure change (When ASV No.2 open)
(P1441 (Bank 1), P1444 (Bank 2))Less than 1 kPa (7.5 mmHg) or more
CASE 2:
Detected times of identifying condition 1 is met4 times or more
1. Cumulative pressure pulsation100 kPa (750 mmHg) or more
P2440: Electromagnetic air switching valve and air switching valve No. 2 are stuck open
Detection CriteriaThreshold
Detected times of identifying condition 1 is met4 times or more
1. Cumulative pressure pulsation100 kPa (750 mmHg) or more

A23473A±A Cross SectionAtmospheric AirSolid Electrolyte
(Zirconia Element)
Platinum
Electrode Heater
Exhaust Gas
Cover Element
A
A
ECM Monitored
A/F Sensor Voltage
Air±Fuel Ratio Alumina
4.0
3.0
2.0
12 13 14 15 16 17
DI±384
± DIAGNOSTICSENGINE
578 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
The A/F sensor generates a voltage* that corresponds to the actual air±fuel ratio. This sensor voltage is used
to provide the ECM with feedback so that it can control the air±fuel ratio. The ECM determines the deviation
from the stoichiometric air±fuel ratio level, and regulates the fuel injection time. If the A/F sensor malfunc-
tions, the ECM is unable to control the air±fuel ratio accurately.
The A/F sensor is the planar type and is integrated with the heater, which heats the solid electrolyte (zirconia
element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas tempera-
ture is low), a current flows into the heater to heat the sensor, in order to facilitate accurate air±fuel ratio
detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat
generated by the heater is conducted to the solid electrolyte though the alumina, therefore the sensor activa-
tion is accelerated.
In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide
(NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air±fuel
ratio must be precisely controlled so that it is always close to the stoichiometric level.
*: Value changes inside the ECM. Since the A/F sensor is the current output element, a current is converted
to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a
constant voltage.

A23662
40 mph (64 km/h)
Idling
IG SW OFF ECT:
75C (167F) or higher
Vehicle Speed
Warming up(d)(f)
10 minutes
or more(g)
10 seconds
or more4 seconds
or moreTime At Least 3 times
(h) (i)
(j) Accelerator Pedal
DepressedAccelerator Pedal
Released (Fuel±cut)
DI±390
± DIAGNOSTICSENGINE
584 Author: Date:
2005 SEQUOIA (RM1146U)
CONFIRMATION DRIVING PATTERN
HINT:
This confirmation driving pattern is used in steps 2, 4, 7, 17 and 21 of the following diagnostic troubleshooting
procedure when using a hand±held tester.
(a) Connect the hand±held tester to DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Clear DTCs (see page DI±43).
(d) Start the engine, and warm it up until the ECT reaches 75C (167F) or higher.
(e) On the hand±held tester, select the following menu items: DIAGNOSIS/ENHANCED OBD II/DATA
LIST/FC IDL.
(f) Drive the vehicle at 40 mph (64 km/h) or more for at least 10 minutes.
(g) Change the transmission to 2nd gear.
(h) Drive the vehicle at proper vehicle speed to perform fuel±cut operation.
HINT:
Fuel±cut is performed under following conditions met:

Accelerator pedal fully released.

Engine speed 2,500 rpm or more (fuel injection returns at 1,000 rpm).
(i) Accelerate the vehicle to 30 mph (48 km/h) or more by depressing the accelerator pedal for at least
10 seconds.
(j) Soon after performing step (8) above, release the accelerator pedal for at least 4 seconds without de-
pressing the brake pedal, in order to execute fuel±cut control.
(k) Stop the vehicle and allow the engine to idle for 10 seconds or more.
(l) Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).
(m) Repeat steps from (8) through (10) above at least 3 times in one driving cycle.
HINT:
Completing all A/F sensor monitors are required to change the value in TEST RESULT.
CAUTION:
Strictly observe of posted speed limits, traffic laws, and road conditions when performing these
drive pattern.

B17393
Engine
RPMEngine
RPM (1) Idling (2) Approximately 2,500 rpm
Fuel Cut
When A/F sensor circuit malfunctioning,
voltage output does not change A/F
Sensor
Voltage A/F
Sensor
Voltage
(1) Idling
Fuel Cut (3) Approximately 4,000 rpm
ºCondition (1), (2)º
Change at approximately 0.66 V Normal Condition:
Malfunction Condition:
ºCondition (3)º
0.76 V or More(1) Idling (2) Approximately 2,500 rpm(3) Approximately 4,000 rpm
(1) Idling
DI±394
± DIAGNOSTICSENGINE
588 Author: Date:
2005 SEQUOIA (RM1146U)
3 Read value output voltage of A/F sensor.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Start the engine and turn the scan tool ON.
(c) Warm up the Air±Fuel Ratio (A/F) sensor at an engine speed of 2,500 rpm for 90 seconds.
CHECK:
(a) Using the scan tool, check the A/F sensor voltage 3 times, once when the engine is in each of the fol-
lowing conditions:
(1) While idling (check for at least 30 seconds)
(2) At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
(3) Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the
throttle valve is fully closed.
Standard:
ConditionsA/F Sensor Voltage VariationsReference
(1) and (2)Changes at approx 0.66 VBetween 0.62 V and 0.7 V
(3)Increases to 0.76 V or moreThis occurs during engine deceleration
(when fuel±cut performed)
For more information, see the diagrams below.
HINT:

If the output voltage of the A/F sensor remains at approximately 0.66 V (see Malfunction Condition
diagram) under any conditions, including those above, the A/F sensor may have an open circuit. (This
will also happen if the A/F sensor heater has an open circuit.)

If the output voltage of the A/F sensor remains at either approximately 0.76 V or more, or 0.56 V or
less (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor
may have a short circuit.

The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and
results in a momentary increase in the A/F sensor output voltage.