TOYOTA SEQUOIA 2001 Service Repair Manual

A23666
Purge VSV
Vent Valve
Vacuum Pump
EVAP Pressure
Positive
Leak Pressure
sec NegativeONON
Sequence
TimeA
10
sec60
Within 15 minutesON
First 0.02 inch
BCD
EVAP Pressure when Vent Valve Stuck OFF (vent):
OK
Malfunction
ON: Open
OFF: Closed
OFF: Vent ON: Closed
10
Standard
sec60
E
± DIAGNOSTICSENGINE
DI±419
613 Author: Date:
2005 SEQUOIA (RM1146U)
(b) P2420: Vent valve stuck open (vent)
In operation C, the vent valve turns ON (closes) and the EVAP (Evaporative Emission) system pressure is
then measured by the ECM, using the pressure sensor, to conduct an EVAP leak check. If the pressure does
not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The
ECM illuminates the MIL and sets the DTC.
MONITOR STRATEGY
RltdDTCP2419Vent valve stuck openRelated DTCsP2420Vent valve stuck closed
Required sensors/componentsVent valve
Frequency of operationOnce per driving cycle
Duration8 sec. (P2419), 10 sec. (P2420)
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
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

DI±420
± DIAGNOSTICSENGINE
614 Author: Date:
2005 SEQUOIA (RM1146U) 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)±
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 ±1.057 kPa)

± DIAGNOSTICSENGINE
DI±421
615 Author: Date:
2005 SEQUOIA (RM1146U) 3. Reference pressure
Saturated
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)
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Vent valve stuck open:
Following valuers are when atmospheric pressure is 760
mmHg (100 kPa)±
One of the following conditions setCondition 1, 2, 3, 4 or 5
1. FTP when 4 sec. after reference pressure measurement
began±7.5 mmHg (±1 kPa) or more
2. Reference pressure±36.38 mmHg (±4.85 kPa) or less
3. Reference pressure±7.93 mmHg (±1.057 kPa) or more
4. Reference pressureNot saturated
5. Reference pressure difference between first and secondMore than 5.25 mmHg (0.7 kPa)
Vent valve stuck closed:
FTP change for 10 sec. after vent valve openedLess than 2.25 mmHg (0.3 kPa)
MONITOR RESULT (MODE 06 DATA)
Refer to page DI±26 for detailed information on Monitor Result.
INSPECTION PROCEDURE
Refer to the EVAP Inspection Procedure (see page DI±460).

A20311
Pressure
SensorECM
VC
AIP
E2 VC
PIM
E2 DI±422
± DIAGNOSTICSENGINE
616 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2430 Secondary Air Injection System Air Flow/
Pressure Sensor Circuit Bank 1
DTC P2431
Secondary Air Injection System Air Flow/Pressure
Sensor Circuit Range/Performance Bank 1
DTC P2432 Secondary Air Injection System Air Flow/
Pressure Sensor Circuit Low Bank 1
DTC P2433 Secondary Air Injection System Air Flow/
Pressure Sensor Circuit High Bank 1
CIRCUIT DESCRIPTION
Refer to DTC P412 on page DI±234.
DTC No.DTC Detecting ConditionTrouble Area
P2430
While the engine is running, voltage output of the pressure
sensor indicates 0.1V or less, or indicates 4.8V or more.
(1 trip detection logic)
P2431
The pressure sensor indicates less than 45 kPa (338 mHg), or
more than 135 kPa (1013 mHg).
(1 trip detection logic)

Pressure sensor
Ohti iit
P2432
While the engine is running, voltage output of pressure sensor
remains below 0.1 V.
(1 trip detection logic)
Open or short in pressure sensor circuit

ECM
P2433
While the engine is running, voltage output of the pressure
sensor remains above 4.8 V.
(1 trip detection logic)
MONITOR DESCRIPTION
The ECM observes the pressure in the secondary air passage
using the pressure sensor located on the air switching valve in
the secondary air injection system.
If there is a defect in the sensor or the sensor circuit, the voltage
level will deviate from the normal operating range, the ECM in-
terprets this deviation as a defect in the pressure sensor circuit
and sets a DTC.
DIDMT±01

± DIAGNOSTICSENGINE
DI±423
617 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P2430Air flow/pressure sensor circuit range check
(Fluctuating)
P2431Air flow/pressure sensor circuit rationality
Related DTCsP2432Air flow/Pressure sensor circuit range check
(Low voltage)
P2433Air flow/pressure sensor circuit range check
(High voltage)
Required sensors/componentsPressure sensor
Frequency of operationContinuous
DurationP2430, P2432, P2433: 0.5 sec.
P2431: 5 sec.
MIL operationP2430, P2432, P2433: Immediate
P2431: 2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
StarterOFF
Time after starter turned from ON to OFF2 sec.±
Battery voltage8 V±
Ignition switchON
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P2430:
Air pressure sensor voltageLess than 0.1 V, or more than 4.8 V
P2432:
Air pressure sensor voltageLess than 0.1 V
P2433:
Air pressure sensor voltageMore than 4.8 V
P2431:
Air pressureLess than 338 mmHg (45 kPa), or more than 1013 mmHg (135 kPa)

A23557
ECM A42
Air Pressure Sensor
VC
AIP
E2
E8 E8 E8
2832 23
VC
AIP
E2EB4
EB4
EB4G±B G±B
B±Y
B±Y
G±W
G±W6 5 15 V
B17412
E8
E2AIP VC
B17439
Wire Harness Side:
Pressure Sensor Connector
A42
E2
AIP VC
DI±424
± DIAGNOSTICSENGINE
618 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open and short in harness and connector between pressure sensor
and ECM (See page IN±35).
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A42 pressure sensor connector.
(c) Disconnect the E8 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
VC (A42±1) ± VC (E8±23)
AIP (A42±2) ± AIP (E8±32)
E2 (A42±3) ± AIP (E8±28)
Below 1 W
VC (A42±1) or VC (E8±23) ±
Body ground
AIP (A42±2) or AIP (E8±32) ±
Body ground
10 kW or higher
NG Repair or replace harness and connector.
OK

B17434
Pressure Gauge
Pressure Sensor
± DIAGNOSTICSENGINE
DI±425
619 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect pressure sensor.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Connect the pressure gauge to the pressure sensor as
shown in the illustration.
(c) Connect the hand±held tester to the DLC3 on the vehicle.
(d) Turn the ignition switch ON and push the hand±held tes-
ter main switch ON (Do not start engine).
(e) Select the following items: DIAGNOSIS / ENHANCED
OBD II / DATA LIST / 2ND AIR PRESS.
CHECK:
Check that the pressure displayed on the hand±held tester fluc-
tuates when applying the pressure to the pressure sensor with
the pressure gauge.
OK:
Pressure fluctuates in response to the pressure ap-
plied with pressure gauge.
NG Replace pressure sensor (See page EC±22).
OK
Replace ECM (See page SF±80).

DI±426
± DIAGNOSTICSENGINE
620 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2444 Secondary Air Injection System Pump Stuck
ON Bank 1
DTC P2445 Secondary Air Injection System Pump Stuck
OFF Bank 1
CIRCUIT DESCRIPTION
Refer to DTC P0412 on page DI±234.
DTC No.DTC Detection ConditionTrouble Area
P2444
Air pump stuck ON.
The secondary air pressure is more than 5 kPa (38 mmHg)
despite the ECM ordering the air pump to turn off.
(2 trip detection logic)
Short in air pump circuit

Air injection driver

Pressure sensor

Open or short in pressure sensor circuit

ECM
P2445
Air pump stuck OFF or air injection volume is insufficient.
The amount of air flow is below the criteria.
(The secondary air pressure is less than specified value de-
spite the ECM ordering the air pump turn ON.)
(2 trip detection logic)

Air pump fuse

Vacuum hose

Air pump assembly

Air injection driver

Open in air pump circuit

Air injection system piping

Pressure sensor

Open or short in pressure sensor circuit

ECM
MONITOR DESCRIPTION
P2444:
The ECM observes the pressure in the secondary air passage using the pressure sensor located on the air
switching valve in the secondary air injection system. The sensor measures the pressure in the secondary
air passage and sends a signal to the ECM.
If the pressure level from the sensor exceed a certain level despite the ECM turning off the air pump, the
ECM interprets this as a fault in the secondary air injection system and sets a DTC.
P2445:
The ECM calculates the amount of air flow in the secondary air system based on the output values of the
pressure sensor and mas air flow meter.
The ECM determines whether the amount of air flow is normal or not according to the calculated value. When
the amount of air flow is below the criteria, the ECM stores the DTC and illuminates the MIL.
DIDMU±01

± DIAGNOSTICSENGINE
DI±427
621 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P2444Air pump is stuck ON
RltdDTCAir pump is stuck OFFRelated DTCsP2445Air flow volume is insufficientP2445
Air pressure sensor is stuck
Required sensors/componentsAIR pump, AIR pressure sensor
Frequency of operationContinuous
Duration
P2444 (Air pump is stuck ON): 20 sec.
P2445 (Air pump is stuck OFF): 8 sec.
P2445 (Air flow volume is insufficient): 8 sec.
P2445 (Air pressure sensor is stuck:) 1.5 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
P2444: Air pump is stuck ON
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Atmospheric pressure570 mmHg (76 kPa)±
Battery voltage11.5 V±
Time after secondary air injection out of
operation10 sec.±
AIR pumpOFF
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
P2445: Air pump is stuck OFF or air insufficient
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Atmospheric pressure570 mmHg (76 kPa)±
Battery voltage11.5 V±
Time after secondary air injection out of
operation6 sec.±
AIR pumpON
Air switching valveON
Air switching valve No. 2 (Bank 1)ON
Air switching valve No. 2 (Bank 2)ON
Engine RPM±3,750 rpm
Delay time after engine started6 sec.±
Air injection pressure sensor failNot detected

DI±428
± DIAGNOSTICSENGINE
622 Author: Date:
2005 SEQUOIA (RM1146U)
P2445: Air pressure sensor is stuck
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
ECT at engine start±5°C (41°F)
IAT at engine start±15°C (5°F)±
Time that ECT is 80°C (176°F) or higher10 to 60 min.
Cumulative intake air amount172 g±
One of the following conditions is metCondition 1, 2 or 3
1. Vehicle speed80 km/h (49.7 mile)±
2. Engine RPM0 rpm±
3. Throttle position0 deg
Air switching valveOFF
Air switching valve No. 2 (Bank 1)OFF
Air switching valve No. 2 (Bank 2)OFF
Air injection pressure sensor failNot detected
TYPICAL MALFUNCTION THRESHOLDS
P2444: Air pump is stuck ON
Detection CriteriaThreshold
Smoothed pressure5 kPa (113 mmHg) or more
(when AI OFF (Air pump OFF, all of air switching valves are OFF)
P2445: Air pump is stuck OFF or air insufficient
Detection CriteriaThreshold
Either of the following conditions is metCondition 1 or 2
1. Air flow value100 L/min. or less
2. Smoothed pressureLess than 1 kPa (7.5 mmHg)
(when AI ON (Air pump ON, all of air switching valves are ON)
P2445: Air pressure sensor is stuck
Detection CriteriaThreshold
Detected times of identifying condition 1 is met4 times or more
Air pressure change5 kPa (113 mmHg) or more