Lexus ES300 (2002 year). Service manual — part 397

E1

ACM1

A61577

5V/Div

GND

10ms/Div

A61576

C58536

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-185

338

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

4

INSPECT ECM

(a)

Connect the oscilloscope between terminals ACM1 and
E1 of ECM connector.

(b)

Warm up engine to normal operating temperature.

(c)

Measure voltage between terminals ACM1 of and E1 of
ECM connector.
Result:

Condition

Voltage

Shift position is D range, and

engine speed is 900 rpm or less.

Pulse generation

Shift position is D range, and

engine speed is 900 rpm or more.

9 - 14 V

Shift position is P range.

9 - 14 V

OK

Go to step 7

NG

5

INSPECT DUTY VACUUM SWITCHING VALVE(RESISTANCE)

(a)

Disconnect the VSV connector for ACM.

(b)

Measure resistance between the terminals.
Resistance: 19 - 21

Ω

at 20

C (68

F)

NG

REPLACE DUTY VACUUM SWITCHING VALVE

OK

A51984

A52933

A59656

3
5

1 2

A54406

E10

E1

ACM1

1

2

A52937

05-186

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

339

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

6

CHECK HARNESS AND CONNECTOR

(a)

Disconnect the connector from the VSV of ACM.

(b)

Remove the E.F.I. ECU Relay.

(c)

Check for open between the terminals 3 of the E.F.I. ECU
Relay in the holder and 1 of the VSV connector for ACM.

NOTICE:
Do not insert the tester leads too hard in the procedure
above, or the holder may be damaged.

Resistance: 1

Ω

or less

(d)

Check for short between the terminals 3 and 2 of the E.F.I.
ECU Relay in the holder.

NOTICE:
Do not insert the tester leads too hard in the procedure
above, or the holder may be damaged.

Resistance: 1 M

Ω

or more

(e)

Disconnect the ECM E10 connector.

(f)

Check for open between the terminals ACM1 of the ECM
connector and 2 of the VSV connector for ACM.
Resistance: 1

Ω

or less

(g)

Check for short between the the terminals ACM1 and E1
of the ECM connector.
Resistance: 1 M

Ω

or more

NG

CHECK AND REPLACE WIRE HARNESS

OK

CHECK AND REPLACE ECM

G

E

H

E

H

F

G

F

A52014

A51989

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

05-187

340

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

7

INSPECT DUTY VACUUM SWITCHING VALVE(OPERATION)

(a)

Disconnect the VSV connector for ACM.

(b)

Check operation of VSV for ACM when battery positive
voltage is applied to the terminals of VSV connector for
ACM or not.
Battery positive voltage is not applied:
The air from pipe G is flowing out through pipe E and
H.
Battery positive voltage is applied:
The air from pipe F is flowing out through pipe E and
H.

NG

REPLACE DUTY VACUUM SWITCHING VALVE

OK

8

INSPECT ENGINE MOUNTING INSULATOR ASSY FRONT

(a)

Disconnect the vacuum hose from front engine mount in-
sulator.

(b)

Using MITYBAC (Hand-Held Vacuum Pump), apply vac-
uum of 80 kPa (600 mmHg, 25 in.Hg) and allow it to stand
for 1 minutes.

(c)

Check that there is no change in the needle movement.

(d)

Check that there is no fluid leakage caused by a brake of
a lower diaphragm.

NG

REPLACE ENGINE MOUNTING INSULATOR
ASSY FRONT

OK

SYSTEM OK

A61332

Vacuum tank

VSV

Air cleaner inlet

Air intake control valve

Throttle valve
opening angle

AICV closed (VSV:ON)

3600rpm
Engine speed

30

A57013

VSV is ON

VSV is OFF

Air

E

F

Air

E

F

05-188

-

DIAGNOSTICS

SFI SYSTEM (1MZ-FE)

341

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

AIR INTAKE CONTROL CIRCUIT

CIRCUIT DESCRIPTION

The air cleaner inlet is divided into two areas, and a air intake control valve and an actuator have been pro-
vided in one of the areas.
As a result, a reduction in intake noise and an increase in the power output have been realized in the low
to the high-speed range of the engine.
When the engine is operating in the low-to mid-speed range, this control operates the air intake control
valve to close one side of the air cleaner inlet.
When the engine speed is more than 3600 rpm. and the opening of the throttle valve is more than 30

, the

ECM activates VSV ON and operates AICV.

WIRING DIAGRAM

Refer to ACIS CONTROL CIRCUIT on page

05-170

.

INSPECTION PROCEDURE

Hand-held Tester:

1

READ VALUE OF HAND-HELD TESTER(VSV FOR AICV)

(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

055CG-03