TOYOTA SEQUOIA 2001 Service Repair Manual

A01995A15196
A15197
IACVIACV closed (VSV: ON)
Intake
Manifold
60°
Throttle valve
opening angle
Engine speed (rpm) 4,700
± DIAGNOSTICSENGINE
DI±499
693 Author: Date:
2005 SEQUOIA (RM1146U)
IACV Control Circuit
CIRCUIT DESCRIPTION
This circuit opens and closes the Intake Air Control Valve (IACV) in response to the engine load in order to
increase the intake efficiency (ACIS: Acoustic Control Induction System).
When the engine speed is 4,700 rpm or more and the throttle valve opening angle is 60° or more, the VSV
is OFF, so the is IACV open. All the other times, the ECM turns the VSV ON and closes the IACV.
DIDG0±01

A14809
B
BW
WB 2
EB2V2
VSV (ACIS)
2 1L±W21
E4ECM
ACIS
MREL 13
E3 P±B
B±R 1
1
1
1 1 1 1 1
12 EFI No. 2
EFI Main Relay
21
3
5
EFI No. 1
12
Engine Room No. 1 R/B
B±L
Battery B±W
W±B J3
J/C
AA
D
D
W±B
ECW
FL MAIN
1
1
4B
4A
FL BLOCK J7
J/C
W±B
1A DI±500
± DIAGNOSTICSENGINE
694 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

A00307
ON
VSV is ON VSV is OFF
Air Filter Air
Air
E
FE
F
BE6653
FI7073 FI7074
± DIAGNOSTICSENGINE
DI±501
695 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Connect hand±held tester, and check operation of VSV for ACIS.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tes-
ter main switch ON.
(c) Select the ACTIVE TEST mode on the hand±held tester.
CHECK:
Check the operation of the VSV when the VSV is operated by
the hand±held tester.
OK:
VSV is ON:
Air from port E flows out through port F.
VSV is OFF:
Air from port E flows out through the air filter.
OK Check for vacuum tank (See page SF±54).
NG
2 Check VSV for ACIS (See page SF±54).
NG Replace VSV for ACIS.
OK

A23670
Wire Harness Side
V12
VSV for ACIS connector
B17413
E5E7
E1
ACIS
DI±502
± DIAGNOSTICSENGINE
696 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and ECM (See page IN±35).
(a) Check the wire harness between the VSV for ACIS and
connector the ECM connector.
(1) Disconnect the VSV for ACIS connector.
(2) Disconnect the E5 and E7 ECM connector.
(3) Check for resistance between the wire harness side
connectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VSV for ACIS (V12±2) ± ACIS (E5±33)Below 1 W
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VSV for ACIS (V12±2) or ACIS (E5±33) ± E1 (E7±1)10 kW or higher
(b) Check the wire harness between the VSV for ACIS con-
nector and the EFI relay.
(1) Disconnect the VSV for ACIS connector.
(2) Remove the EFI relay from the engine room R/B.
(3) Check for resistance between the wire harness side
connectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VSV for ACIS (V12±1) ± EFI relay terminal 3 of R/BBelow 1 W
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±35).

A19655A20059
STSW
ACCR
STAR
(NE)
Engine SpeedStarterPark/Neutral
Position SW
N P ST RelayACC Cut
Relay
Ignition
SW
ACC
ST2
ACCR
STSW
STAR BatteryECM
± DIAGNOSTICSENGINE
DI±503
697 Author: Date:
2005 SEQUOIA (RM1146U)
Cranking Hold Function Circuit
CIRCUIT DESCRIPTION
The starter is controlled by the ECM, when the ECM detects a start signal (STSW) from the ignition switch,
this system monitors the engine speed (NE) and continues to operate the starter until it has determined that
the engine has started (engine speed reaches approximately 500 rpm). If the engine is already running and
the ignition switch is turned to START, the ECM will not operate the starter.
WIRING DIAGRAM
Refer to DTC P0617 on page DI±298.
INSPECTION PROCEDURE
Hand±held tester:
1 Check operation of engine cranking.
CHECK:
When turning the ignition switch to the START position, check whether the starter motor starts.
OK:
Starter motor starts.
OK Check for intermittent problems (See page
DI±11).
NG
DID8M±01

B17411
STA(+) E1(±)
STSW(+)E6
DI±504
± DIAGNOSTICSENGINE
698 Author: Date:
2005 SEQUOIA (RM1146U)
2 Connect hand±held tester, and check STA signal.
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) Enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / STARTER SIG.
CHECK:
Read the STA signal on the hand±held tester while the starter operates.
OK:
Ignition Switch PositionONSTART
STARTER SIGOFFON
NG Go to step 5.
OK
3 Check voltage between terminal STAR, STSW and E1 of ECM connector.
CHECK:
Measure the voltage between the terminals of the E6 ECM con-
nectors, while cranking the engine (ignition switch START posi-
tion).
OK:
Standard:
Tester ConnectionSpecified Condition
STA (E6±11) ± E1 (E6±1)9 to 14 V
STSW (E6±12) ± E1 (E6±1)9 to 14 V
RESULT:
Terminal STARTerminal STSWProceed to
9 to 14 V9 to 14 VA
0 V9 to 14 VB
0 V0 VC
B Replace ECM (See page SF±80).
C Go to step 9.
A

D14154
Component Side:
A19288
± DIAGNOSTICSENGINE
DI±505
699 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check park/neutral position switch.
PREPARATION:
Remove the P1 park/neutral position switch connector.
CHECK:
Check resistance between each terminal shown below when
the shift lever is moved to each range.
Shift rangeTerminal No. to continuity
P1 ± 36 ± 9
R2 ± 3±
N3 ± 56 ± 9
D3 ± 7±
23 ± 4±
L3 ± 8±
OK:
Below 1 W
NG Replace the park/neutral position switch.
OK
Check and repair harness and connector be-
tween park/neutral position switch and ECM.
5 Check starter relay.
(a) Remove the starter relay from the engine room R/B.
(b) Inspect the starter relay.
Standard:
Tester ConnectionSpecified Condition
3 ± 510 kW or higher
3 ± 5Below 1 W
(Apply battery voltage to terminals 1 and 2)
NG Replace starter relay.
OK

A23563
Wire Harness Side
Park/Neutral position switch ConnectorN1
A21559
Engine Room R/B No.2
Starter Relay
DI±506
± DIAGNOSTICSENGINE
700 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check for open and short in harness and connector between park/neutral posi-
tion switch and starter relay.
(a) Check the harness and the connector between the park/
neutral position switch connector and the starter relay.
(1) Disconnect the park/neutral position switch con-
nector.
(2) Remove the starter relay from the engine room R/B.
(3) Check for resistance between the wire harness side
connectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
Park/Neutral position switch (N1±6) ± Starter relay (1)Below 1 W
Standard (Check for short):
Symbols (Terminal No.)Specified condition
Park/Neutral position switch (N1±6) or Starter relay (1)
± Body ground10 kW or higher
(b) Check the harness and the connector between the starter
relay and the body ground.
(1) Remove the starter relay from the engine room R/B.
(2) Check for resistance between the starter relay and
the body ground.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
Starter relay (2) ± Body groundBelow 1 W
NG Repair or replace harness or connector.
OK

A21559
Engine Room R/B No.2
Starter Relay
± DIAGNOSTICSENGINE
DI±507
701 Author: Date:
2005 SEQUOIA (RM1146U)
7 Check engine room R/B No.2 (Starter relay voltage).
PREPARATION:
Remove the starter relay from the engine room R/B No.2.
CHECK:
Measure the voltage between the terminal of the engine room
R/B and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
Starter relay (5) ± Body ground9 to 14 V
NG Check and repair harness and connector be-
tween starter relay and battery.
OK
8 Check starter (See page ST±15).
NG Repair or replace starter.
OK

I08467
LOCKACC
ON
START
DI±508
± DIAGNOSTICSENGINE
702 Author: Date:
2005 SEQUOIA (RM1146U)
9 Check ignition switch.
PREPARATION:
(a) Remove the lower finish panel.
(b) Disconnect the ignition switch connector.
CHECK:
Check resistance between terminals.
OK:
Standard:
Switch PositionTerminal ConditionSpecified Condition
LOCKAlways10 kW or more
ACC1 ± 3Below 1 W
ON1 ± 2 ± 3
5 ± 6Below 1 W
START1 ± 2
4 ± 5 ± 6Below 1 W
NG Replace ignition switch.
OK
Check for open in harness and connector be-
tween ECM and ignition switch, ignition
switch and battery (See page IN±35).