2001 TOYOTA SEQUOIA Page 18

± DIAGNOSTICSENGINE
DI±309
503 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P1440 Secondary Air Injection System Control
Valve Circuit Bank 1
DTC P1443 Secondary Air Injection System Control
Valve Circuit Bank 2
CIRCUIT DESCRIPTION
Refer to DTC P0412 on page DI±234.
DTC No.DTC Detection ConditionTrouble Area
P1440
AIV1 terminal voltage becomes less than half of the +B voltage
while the VSV for air injection control is not operating.
(1 trip detection logic)
Open or short in VSV for air injection control circuit (Bank 1)

VSV power source

VSV for air injection control (Bank 1)

ECM
P1443
AIV2 terminal voltage becomes less than half of the +B voltage
while the VSV for air injection control is not operating.
(1 trip detection logic)
Open or short in VSV for air injection control circuit (Bank 2)

VSV power source

VSV for air injection control (Bank 2)

ECM
MONITOR DESCRIPTION
The ECM detects an open or short in the circuit of the VSV for air injection control according to the AIV1
(AIV2) terminal voltage, stores the DTC, and then illuminates the MIL. When the AIV1 (AIV2) terminal voltage
is less than half of the +B voltage while the VSV for air injection control is not operating, the ECM determines
it as a malfunction.
MONITOR STRATEGY
RltdDTC
P1440Secondary air injection system control valve cir-
cuit (Bank 1) range check
Related DTCs
P1443Secondary air injection system control valve cir-
cuit (Bank 2) range check
Required sensors/componentsVSV for air injection control
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
DIDMQ±01

DI±310
± DIAGNOSTICSENGINE
504 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
P1440:
EngineRunning
Air switching valve No. 2 (Bank 1)Not operating
P1443:
EngineRunning
Air switching valve No. 2 (Bank 2)Not operating
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P1440:
Air switching valve No. 2 (Bank 1) output terminal levelLow
P1443:
Air switching valve No. 2 (Bank 2) output terminal levelLow

B17515
± DIAGNOSTICSENGINE
DI±313
507 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check resistance of VSV for air injection control.
PREPARATION:
(a) Disconnect the connector from the VSV.
(b) Disconnect the 2 vacuum hoses from the VSV.
CHECK:
Measure the resistance between the VSV terminals.
OK:
Standard:
Tester ConnectionSpecified Condition
1 ± 233 to 39 W at 20°C (68°F)
1 ± Body ground10 kW or higher
2 ± Body ground10 kW or higher
NG Replace VSV for air injection control.
OK
Replace ECM. (See page SF±80)

DI±314
± DIAGNOSTICSENGINE
508 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P1441 Secondary Air Injection System Switching
Valve No.2 Stuck Open Bank 1
DTC P1444 Secondary Air Injection System Switching
Valve No.2 Stuck Open Bank 2
DTC P2440 Secondary Air Injection System Switching
Valve Stuck Open Bank 1
CIRCUIT DESCRIPTION
Refer to DTC P0412 on page DI±234.
DTC No.DTC Detection ConditionTrouble Area
P1441
Air switching valve No.2 (bank 1) stuck open:
The pressure sensor detects exhaust pulsation, when both of
air switching valve No.2 are OFF (and air switching valve ON).
(2 trip detection logic)
VSV for air injection control circuit (Bank 1)

Air switching valve No.2 (Bank 1)

VSV for air injection system (Bank 1)

ECM
P1444
Air switching valve No.2 (bank 2) stuck open:
The pressure sensor detects exhaust pulsation, when both of
air switching valve No.2 are OFF (and air switching valve ON).
(2 trip detection logic)
VSV for air injection control circuit (Bank 2)

Air switching valve No.2 (Bank 2)

VSV for air injection system (Bank 2)

ECM
P2440
Air switching valve stuck open:
The pressure sensor detects exhaust pulsation when the sys-
tem does not operate (both of air switching valve No.2 OFF,
and air switching valve OFF and air pump OFF).
This DTC means open stuck of air switching valve and ºair
switching valve No.2 (bank 1 or bank 2)º
(1 trip detection logic)
Air switching valve

Air switching valve No.2 (Bank 1 and/or 2)

VSV for air injection system (Bank 1 and/or 2)

Air injection driver

Air injection driver circuit

ECM
DIDMR±01

± DIAGNOSTICSENGINE
DI±317
511 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P1441Air switching valve No. 2 (Bank 1) is stuck open
Related DTCsP1444Air switching valve No. 2 (Bank 2) is stuck openRelated DTCs
P2440Air switching valve and air switching valve No. 2
are stuck open
Required sensors/componentsPressure sensor, Air switching valve No. 2 (Bank 1, 2), Electromagnetic air switching valve
Frequency of operationContinuous
Duration
P1441 (Air switching valve No. 2 (Bank 1) is stuck open): 20 sec.
P1444 (Air switching valve No. 2 (Bank 2) is stuck open): 20 sec.
P2440 (Air switching valve and air switching valve No. 2 are stuck open): 18 sec.
MIL operation
P1441 (Air switching valve No. 2 (Bank 1) is stuck open): 2 driving cycles
P1444 (Air switching valve No. 2 (Bank 2) is stuck open): 2 driving cycles
P2440 (Air switching valve and air switching valve No. 2 are stuck open):
1 driving cycle
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
P1441, P1444: Air switching valve No. 2 bank 1 and/or bank 2 are stuck open
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
CASE 1
Atmospheric pressure76 kPa (570 mmHg)±
Battery voltage11.5 V±
Time after secondary air injection out of
operation10 sec.±
AIR pumpOFF
Time after engine start10 sec.±
Air switching valve No. 2 (Bank 1)OFF
Air switching valve No. 2 (Bank 2)OFF
Air injection pressure sensor failNot detected
Air switching valveON
Engine RPM±3,750 rpm
CASE 2
Atmospheric pressure76 kPa (570 mmHg)±
Battery voltage11.5 V±
AIR pumpOFF
Time after engine start10 sec.±
Air switching valve No. 2 (Bank 1)OFF
Air switching valve No. 2 (Bank 2)OFF
Air injection pressure sensor failNot detected
Engine load0%±
Intake air amount40 g/sec±
IAT at engine start±15°C (5°F)±
ECT at engine start±5°C (41°F)

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

± DIAGNOSTICSENGINE
DI±319
513 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 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

A23671
Port APort B
Air
A23672
Port APort B
Battery Air
± DIAGNOSTICSENGINE
DI±321
515 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check any other DTCs output (In addition to secondary air injection system
DTCs).
PREPARATION:
(a) Connect hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
CHECK:
(a) Read DTCs.
RESULT:
Display (DTC Output)Proceed To
ºP1441 and/or P1444º and P2440A
P1441 and/or P1444B
ºP1441 and/or P1444 and/or P2440º and other DTCsC
HINT:
If any DTCs other than P1441, P1444 or P2440 are output, troubleshoot those DTCs first.
B Go to step 7.
C Go to DTC chart (See page DI±58).
A
2 Check air switching valve operation.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Remove the air switching valve.
CHECK:
Blow air into port A and check that air is not discharged from port
B.
OK:
Not discharged
CHECK:
(a) Apply battery positive across the terminals.
(b) Blow air into port A and check that air is discharged from
port B.
OK:
Discharged