Lexus ES300 (2002 year). Manual - part 393

A62461

Valve No.2

Valve No.1

Throttle Valve

Valve No.1, No.2 closed (VSV: ON)

Valve No.1 open (VSV: OFF)

Engine Speed

Valve No.2 closed (VSV: ON)

Throttle V

alve

Valve No.1, No.2 open (VSV: OFF)

Opening Angle

3,000 rpm

4,100 rpm

A57003

B - G

FL 

MAIN

W - B

1K

E6

E.F.I.

MREL

ACIS

ACI1

ECM

E01

+B

2

5

6

3

15

8

Battery

ED

E10

E01

R - Y

Y - G

B - W

1

1

2

2

1B

1C

1A

3

1

2

5

E.F.I. ECU Relay

Engine Room J/B

VSV for ACIS No.1

VSV for ACIS No. 2

B - W

B - W

1

1

Engine Room

R/B

14

B - G

VSV for AICV No.3

E10

25

E10

AICV

1

2

W

B - W

05-170

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

323

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

ACIS CONTROL CIRCUIT

CIRCUIT DESCRIPTION

This circuit is opens and closes the Intake Air Control Valve in response to the engine load in order to in-
crease the intake efficiency (ACIS: Acoustic Control Induction System).
When the engine speed is 4,100 rpm or less and the throttle valve opening angle is 30

°

 or more, the ECM

turns the two VSV ON or OFF and operate the Intake Air Control Valve.

WIRING DIAGRAM

051MU-11

A60850

VSV is ON

VSV is OFF

Air

E

F

Air

E

F

Air Filter

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-171

324

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

INSPECTION PROCEDURE

Hand-held Tester:

1

PERFORM ACTIVE TEST BY HAND-HELD TESTER(VSV FOR ACIS)

(a)

Turn the ignition switch ON and hand-held tester main
switch ON.

(b)

Select the INTAKE CTRL VSV from the ACTIVE TEST
menu on the hand-held tester.

(c)

Check the operation of the VSV when the VSV is oper-
ated by the hand-held tester.
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

INSPECT VACUUM TANK

NG

2

CHECK VSV(FOR ACIS) (See page 

13-2

)

NG

REPLACE VACUUM SWITCHING VALVE ASSY
NO.1

OK

3

CHECK HARNESS AND CONNECTOR(E.F.I. ECU RELAY  -  ECM)

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

OK

CHECK AND REPLACE ECM

OBDII scan tool (excluding Hand-held Tester):

1

CHECK VSV(FOR ACIS) (See page 

13-2

)

NG

REPLACE VACUUM SWITCHING VALVE ASSY
NO.1

OK

A53763

ACIS

E2

ACI1

05-172

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

325

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

INSPECT ECM

(a)

Turn the ignition switch ON.

(b)

Measure the voltage between terminals ACI1, ACIS and
E2 of the ECM connector.
Voltage: 9 - 14 V

NG

CHECK HARNESS AND CONNECTOR

OK

3

INSPECT VACUUM TANK (See page 

13-2

)

NG

REPAIR OR REPLACE

OK

CHECK AND REPLACE ECM

051LR-06

A57014

ECM

Mass Air Flow Meter

VSV
(for Air Intake Control Valve)

DLC3

Vapor 
Pressure sensor

Fuel Pump

VSV 
(for Canister Closed Valve)

Accelerator Pedal
Position Sensor

Crankshaft Position 
Sensor

VSV 
(for ACIS No. 2)

VSV 
(for EVAP)

Engine Coolant 
Temp.Sensor

Ignition Coil
with Igniter

Injector

Throttle Position 
Sensor

VSV (for ACIS No. 1)

Heated Oxygen Sensor 
(Bank 2, Sensor 2)

Air Fuel Ratio Sensor 
(Bank 1, Sensor 1)

Heated Oxygen Sensor 
(Bank 1, Sensor 2)

Air Fuel Ratio Sensor 
(Bank 2, Sensor 1)

Knock Sensor

VSV 
(for Pressure Swithching Valve)

VVT Sensor 
(Bank 1)

Knock Sensor

Camshaft Timing 
Oil Control Valve

VVT Sensor 
(Bank 2)

Camshaft Timing 
Oil Control Valve

05-26

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

179

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

LOCATION