2001 TOYOTA SEQUOIA Page 18

B17426
± DIAGNOSTICSENGINE
DI±333
527 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Refer to DTC P1441, P1444 and P2440 on page DI±314.
INSPECTION PROCEDURE
1 Check any other DTCs output (In addition to secondary air injection system
DTCs).
PREPARATION:
(a) Connect a 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
ºP1442 and/or P1445º and P2441A
P1442 and/or P1445B
ºP1442 and/or P1445 and/or P2441º and other DTCsC
HINT:
If any DTCs other than P1441 and/or P1444 and P2440 are output, troubleshoot those DTCs first.
B Go to step 6.
C Go to DTC chart (See page DI±58).
A
2 Check vacuum hose between throttle body and VSV for air injection control.
CHECK:
(a) Check that the vacuum hoses between the throttle body
and VSV for air injection control are securely connected.
OK:
The vacuum hoses are securely connected.
CHECK:
(a) Check the vacuum hoses for blockage or damage.
OK:
The vacuum hoses are no blockages and damage.
NG Repair or replace vacuum hoses.
OK

B17440
A46
Air Switching Valve Connector Wire Harness Side:
DI±334
± DIAGNOSTICSENGINE
528 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check voltage between terminal 1 of air switching valve and body ground.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A46 air switching valve connector.
(c) Connect the hand±held tester to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
CHECK:
(a) When the air switching valve is operated using the hand±
held tester, measure voltage between terminal A46±1 of
the air switching valve connector and body ground.
(b) Select the following menu items: DIAGNOSIS/EN-
HANCED OBD II/SYSTEM CHECK/AIR INJ CHECK/
MANUAL OPERATION/OPERATION 1 and 4
HINT:
OPERATION 1: AP:OFF, EASV:CLOSE, ASV1:CLOSE,
ASV2:CLOSE
OPERATION 4: AP:OFF, EASV:OPEN, ASV1:CLOSE,
ASV2:CLOSE
NOTICE:
This test only allows technicians to operate the AI system
for 5 seconds. Furthermore, the test can be performed 4
times a trip. If the test is repeated, intervals of at least 30
seconds are required between tests.
While the AI system operation using the hand±held tester
is prohibited, the tester displays the prohibition (WAIT or
ERROR). If the ERROR (AI STATUS NG) is displayed on the
tester, stop the engine for 10 minutes and then try again..
OK:
Standard:
Tester operationTester ConnectionSpecified Condition
Operation 4A46±1 ± Body ground10 V or more
Operation 1A46±1 ± Body groundBelow 1.0 V
NG Go to step 12.
OK

B17436
A23671
Port APort B
Air
A23672
Port APort B
Battery Air
± DIAGNOSTICSENGINE
DI±335
529 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check all air injection pipes and hoses of air injection system.
CHECK:
(a) Remove the intake manifold (see page EM±36).
(b) Check all pipes and hoses of the air injection system.
OK:
All the air injection pipes and hoses are securely con-
nected.
CHECK:
(a) Check all pipes and hoses of the air injection system for
blockage or damage.
OK:
The air injection system pipes and hoses have no
blockage or damage.
NG Repair or replace pipe or hose.
OK
5 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
NG Replace air switching valve and go to step 6.
OK

A23451
B17516
AirA
B17517
AirA
± DIAGNOSTICSENGINE
DI±339
533 Author: Date:
2005 SEQUOIA (RM1146U)
10 Check air injection pipe between air switching valve No.2 and exhaust manifold.
CHECK:
(a) Check that the air injection pipe between the air switching
valve(s) No.2 and exhaust manifold is securely con-
nected.
OK:
The air injection pipe is securely connected.
CHECK:
(a) Check the air injection pipe for blockages and damage.
OK:
The air injection pipe have no blockages and damage.
NG Repair or replace air injection pipe.
OK
Check for intermittent problems
(See page DI±11).
11 Check VSV for air injection control.
PREPARATION:
Disconnect the 2 vacuum hoses.
CHECK:
Check that air does not flow from the port A as shown in the il-
lustration.
OK:
Not flow from port A
CHECK:
Apply battery positive across the terminals, check that air flows
from the port A.
OK:
Flow from port A
NG Replace VSV for air injection control.
OK

B17412
E8
AIV1
AIV2
B17437
V14
VSV Connector V15
Wire Harness Side:
DI±340
± DIAGNOSTICSENGINE
534 Author: Date:
2005 SEQUOIA (RM1146U)
12 Check for open and short circuit in harness and connector between ECM and
VSV for air injection system control
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the E8 ECM connector.
(c) Disconnect the VSV for air injection system control con-
nector.
CHECK:
Measure the resistance between the VSV connector and ECM.
OK:
Standard:
Tester connectionSpecified condition
E8±27 (AIV1) ± V14±2Below 1 W
E8±26 (AIV1) ± V15±2Below 1 W
CHECK:
Measure the resistance between the VSV connector and body
ground.
OK:
Standard:
Tester connectionSpecified condition
E8±27 (AIV1) or V14±2 and Body
ground10 KW or higher
E8±26 (AIV1) or V15±2 and Body
ground10 KW or higher
NG Repair or replace harness or connector.
OK

B17444
Wire Harness Side:
Air Injection Driver Connector
A41
VV
B17440
A46
Air Switching Valve Connector Wire Harness Side:
B17440
A46
Air Switching Valve Connector Wire Harness Side:
± DIAGNOSTICSENGINE
DI±341
535 Author: Date:
2005 SEQUOIA (RM1146U)
13 Check for open and short in harness and connector between air injection driver
and air switching valve.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A41 air injection driver connector.
(c) Disconnect the A46 air switching valve connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
VV (A41±6) ± A46±1Below 1 W
VV (A41±6) or A46±1 ±
Body ground10 kW or higher
NG Repair or replace harness or connector and go
to step 6.
OK
14 Check for open in harness and connector between air switching valve and body
ground.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A46 air switching valve connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
A46±2 ± Body groundBelow 1 W
NG Repair or replace harness or connector and go
to step 6.
OK

B17444
Wire Harness Side:
Air Injection Driver Connector
A41
SIV
B17417
E4
AIRV
DI±342
± DIAGNOSTICSENGINE
536 Author: Date:
2005 SEQUOIA (RM1146U)
15 Check for open and short in harness and connector between air injection driver
and ECM.
PREPARATION:
(a) Disconnect the air injection driver connector.
(b) Disconnect the E4 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
SIV (A41±3) ± AIRV (E4±4)Below 1 W
SIV (A41±3) or AIRV (E4±4) ±
Body ground10 kW or higher
NG Repair or replace harness or connector and go
to step 6.
OK
Replace ECM (See page SF±80).

± DIAGNOSTICSENGINE
DI±343
537 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P1613 Air Injection System Air Injection Driver
CIRCUIT DESCRIPTION
Refer to DTC P0412 on page DI±234.
DTC No.DTC Detection ConditionTrouble Area
P1613
Either of the following condition (a) or (b) is met:
(a) All of the following conditions are met (1 trip detection logic):

Either the air pump or air switching valve does not operate.

Air injection driver outputs a normal signal (80% duty signal)
(b) All of the following conditions are met (1 trip detection logic):

Air injection driver outputs an abnormal duty signal (duty sig-
nal excluding 0, 20, 40, 60, 80, 100%)

Air injection driver (AID)

Open in air injection driver ground circuit
P1613
All of the following conditions are met (1 trip detection logic):
(a) Air injection system operates (Air pump ON and all ASV
ON)
(b) Air injection driver outputs an air pump malfunction signal
(0% duty signal)
Short in diagnostic information signal circuit (AID ± ECM)

Open or short in air pump and air switching valve command
signal circuit (AID ± ECM)

Air injection driver (AID)

Open in air injection driver ground circuit

ECM
P1613Air injection driver outputs an abnormal duty signal (100% duty
signal) (1 trip detection logic)

Open or short in AID power source circuit

Open in diagnostic information signal circuit (AID ± ECM)

Air injection driver (AID)

ECM
MONITOR DESCRIPTION
When the air injection system operation is required while the engine is warming up, the ECM transmits com-
mand signals to the Air Injection Driver (AID) to drive the air pump and air switching valve.
AID detects an open or short in the air pump and air switching valve circuit according to the terminal voltage
and sends a signal as diagnostic information to the ECM.
If the air injection system drive circuit or the AID itself has a malfunction, the AID sends a malfunction signal
(duty signal) as a diagnostic information signal to the ECM (when the system is normal, a system normal
signal is sent).
The ECM sets the DTC based on the diagnostic information from the AID.
Example:
(1) The duty ratio of the diagnostic information signal output from the AID is 0 or 100% (remains at
0 V or battery voltage).
(2) The duty ratio output from the AID is the ratio to output the impossible (excluding 0, 20, 40, 60,
80, 100%).
(3) The AID outputs the normal signal (normal duty signal: 80%) while the system is not operating.
DIDMX±01