Toyota Sequoia (2005). Manual - part 176

A01995 A15196

A15197

IACV

IACV closed (VSV: ON)

Intake 
Manifold

60

°

Throttle valve 
opening angle

Engine speed (rpm)

4,700

–

DIAGNOSTICS

ENGINE

DI–499

693

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

B

W

W

B

2

EB2

V2
VSV (ACIS)

2

1

L–W

21

E4

ECM

ACIS

MREL

13

E3

P–B

B–R

1

1

1

1

1

1

1

1

1

2

EFI No. 2

EFI Main Relay

2

1

3

5

EFI No. 1

1

2

Engine Room No. 1 R/B

B–L

Battery

B–W

W–B

J3
J/C

A

A

D

D

W–B

EC

W

FL MAIN

1

1

4B

4A

FL BLOCK

J7
J/C

W–B

1A

DI–500

–

DIAGNOSTICS

ENGINE

694

WIRING DIAGRAM

A00307

ON

VSV is ON

VSV is OFF

Air Filter

Air

Air

E

F

E

F

BE6653
FI7073 FI7074

–

DIAGNOSTICS

ENGINE

DI–501

695

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

E5

E7

E1

ACIS

DI–502

–

DIAGNOSTICS

ENGINE

696

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 

Ω

Standard (Check for short):

Symbols (Terminal No.)

Specified condition

VSV for ACIS (V12–2) or ACIS (E5–33) – E1 (E7–1)

10 k

Ω

 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/B

Below 1 

Ω

NG

Repair or replace harness or connector.

OK

Check and replace ECM (See page 

IN–35

).