Last Modified: 4-30-2014 6.6 J Doc ID: RM000000TMS007X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: IACV Control Circuit; 2006 MY LX470 [05/2005 -        ]

IACV Control 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 IACV is open (VSV: OFF). At all other times, the IACV is closed (VSV: ON).

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (VACUUM SWITCHING VALVE)

(a) Disconnect the vacuum hose from port F on the vacuum switching valve (for ACIS).

(b) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.

(c) Start the engine.

(d) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INTAKE CTL VSV1. Operate the ACIS VSV.

(e) Check the VSV air flow when switching the VSV.

OK:

Tester Condition

Specified Condition

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
NG

GO TO STEP 4

OK

2.

CHECK VACUUM HOSES (INTAKE MANIFOLD - VACUUM SWITCHING VALVE, VACUUM SWITCHING VALVE - INTAKE AIR CONTROL VALVE)

(a) Check the condition of the vacuum hoses between the intake manifold, vacuum switching valve (for ACIS) and IACV.

(1) The vacuum hoses are connected securely.

(2) The vacuum hoses are not cracked or damaged.

OK:

The vacuum hoses are connected securely and not cracked or damaged.

NG

REPAIR OR REPLACE VACUUM HOSES

OK

3.

INSPECT INTAKE AIR CONTROL VALVE

(a) Inspect intake air control valve 2006 MY LX470 [05/2005 -        ]; 2UZ-FE INTAKE: INTAKE AIR CONTROL SYSTEM: ON-VEHICLE INSPECTION .

NG

REPLACE INTAKE AIR CONTROL VALVE

OK

REPLACE ECM

4.

INSPECT VACUUM SWITCHING VALVE (OPERATION)

(a) Check that air flows from port E to the air filter.

(b) Apply positive (+) battery voltage across the terminals.

(c) Check that air flows from port E to port F.
NG

REPLACE VACUUM SWITCHING VALVE

OK

5.

CHECK HARNESS AND CONNECTOR (VACUUM SWITCHING VALVE - ECM, VACUUM SWITCHING VALVE - EFI OR ECD NO. 2 FUSE)

(a) Check harness and connector 2006 MY LX470 [05/2005 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE .

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

REPLACE ECM