Page 625 of 4323

± 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)
Page 626 of 4323
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
Page 627 of 4323
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).
Page 628 of 4323

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
Page 629 of 4323

± 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
Page 630 of 4323

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
Page 631 of 4323

± DIAGNOSTICSENGINE
DI±429
623 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR RESULT
Refer to page DI±26 for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (refer to ºConfirmation Monitorº).
MID (Monitor Identification Data) is assigned to each emissions±related component.
TID (Test Identification Data) is assigned to each test value.
Scaling is used to calculate the test value indicated on generic OBD ll scan tools.
Secondary air injection (AIR) system
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$71$E1Multiply by 0.01
(g/s)Test value of AIR amount insufficientMinimum test limitMaximum test limit
$71$E2Multiply by 0.01
(kPa)Test value of AIR pump stuck ONMinimum test limitMaximum test limit
$71$E3Multiply by 0.01
(kPa)Test value of AIR pump stuck OFFMinimum test limitMaximum test limit
$71$E4Multiply by 0.01
(kPa)Test value of AIR control valve ONMinimum test limitMaximum test limit
$71$E5Multiply by 0.01
(kPa)Test value of AIR control valve OFFMinimum test limitMaximum test limit
$71$E6Multiply by 0.01
(kPa)Test value of AIR pressure change for
AIR valveMinimum test limitMaximum test limit
$71$E7Multiply by 0.01
(kPa)Test value of AIR pressure change for
AIR VSV bank 1Minimum test limitMaximum test limit
$71$E8Multiply by 0.01
(kPa)Test value of AIR pressure change for
AIR VSV bank 2Minimum test limitMaximum test limit
$71$E9Multiply by 0.01
(kPa)Test value of AIR pressure pulsation for
AIR VSV when AIR pressure is lowMinimum test limitMaximum test limit
WIRING DIAGRAM
Refer to DTC P0412 on page DI±234.
Page 632 of 4323
DI±430
± DIAGNOSTICSENGINE
624 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
To check the pressure condition in the secondary air passage, the hand±held tester is available.
1 Is the DTC P2444 and/or P2445 being output?
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) Select the following items: DIAGNOSIS/ENHANCED OBD II/DTC INFO/CURRENT CODES.
CHECK:
Read the DTCs.
RESULT:
Display (DTC output)Proceed to
P2445A
P2444B
P2444 and P2445B
ºP2444 and P2445º and other DTCsC
HINT:
If any other codes besides P2444 or P2445 is output, perform troubleshooting for those DTCs first.
B Go to step 7.
C Go to DTC chart (See page DI±58).
A