05-660
DIAGNOSTICS - SFI SYSTEM (3MZ-FE) 05EY4-05
ACIS CONTROL CIRCUIT
CIRCUIT DESCRIPTION
The ECM opens and closes the Intake Air Control (IAC) valve No. 2 in response to engine speed (RPM/NE).
This system improves intake manifold tuning for better efficiency at low and high engine rpm. When the en-
gine speed is 4,000 rpm or less and the throttle valve opening angle is 30 or more, the ECM turns the VSV
ON to operate the IAC valve.
HINT:
ACIS stands for ”Acoustic Control Induction System”.
Valve closed (VSV: ON)
Opening Angle
Throttle Valve
IAC
Valve
30°
No. 2
Throttle Valve
4,000 rpm
Engine Speed
A87796
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 850
05-661
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
WIRING DIAGRAM
V2 ECM
Engine Room R/B No. 2 VSV for IAC
Valve No. 2
EFI NO. 2 1 15
B-W B-R R-Y ACIS
2 2 EB1 E7
1 2 1 2
Y
Engine Room J/B
3 2D
5 13 8
P-L B MREL
2B IK3 E5
3 EFI Relay 1
5 2
1
EFI NO. 1 BR
E7 E1
1 2I 4 2F
3 W-B
F7
FL Block
Assy
1
A A
W J2 J7
J/C J/C
FL A
Main
BR
Battery EH ED
A88701
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 851
05-662
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
INSPECTION PROCEDURE
Hand-held tester:
1 PERFORM ACTIVE TEST USING HAND-HELD TESTER (OPERATE VSV FOR IAC
VALVE NO. 2)
VSV is ON VSV is OFF
(a) Disconnect the vacuum hose.
(b) Connect the hand-held tester to the DLC3.
Air Air
Air (c) Turn the ignition switch ON and push the hand-held tes-
Filter ter main switch ON.
(d) Enter the following menus: DIAGNOSIS / ENHANCED
OBD II / ACTIVE TEST / INTAKE CTL VSV1. Operate the
VSV.
(e) Check the VSV operation when it is operated by the
Port F Port E Port F Port E
A67588 hand-held tester.
OK:
Tester Operation 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
OK Go to step 4
NG
2 CHECK VSV FOR IAC VALVE NO.2 (OPERATION)
(a) Air (a) Check that air flows from port E to the air filter.
Air Filter
Port E
A54315
(b)
(b) Apply battery positive voltage across the terminals.
Air (c) Check that air flows from port E to port F.
Port E
Battery
Port F A54316 NG REPLACE VSV
OK
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 852
05-663
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
3 CHECK WIRE HARNESS (VSV FOR IAC VALVE NO. 2 - ECM, VSF FOR IAC VALVE
NO. 2 - EFI RELAY)
(a) Check the wire harness between the VSV and ECM.
Wire Harness Side
(1) Disconnect the V2 VSV connector.
V2
(2) Disconnect the E7 ECM connector.
VSV for IAC Valve No. 2
(3) Check the resistance of the wire harness side con-
nectors.
Standard:
Tester Connection Specified Condition
V2-2 - E7-15 (ACIS) Below 1 Ω
V2-2 or E7-15 (ACIS) - Body ground 10 kΩ or higher
E7
ECM
Y
ACIS
A85675
A81699 A87763
Wire Harness Side (b) Check the wire harness between the VSV and EFI relay.
V2
(1) Disconnect the V2 VSV connector.
VSV for IAC Valve No. 2 (2) Remove the EFI relay from the engine room J/B.
(3) Check the resistance of the wire harness side con-
nectors.
Standard:
Tester Connection Specified Condition
V2-1 - J/B EFI relay terminal 3 Below 1 Ω
Engine Room J/B
EFI Relay
A85448
A90291 A92391 NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 853
05-664
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
4 CHECK VACUUM HOSES (INTAKE MANIFOLD - INTAKE AIR CONTROL VALVE,
INTAKE AIR CONTROL)
(a) Check that the vacuum hoses are:
Connected correctly.
Are not loose or disconnected.
Do not have cracks, holes or damage.
NG REPAIR OR REPLACE VACUUM HOSES
OK
5 INSPECT INTAKE AIR CONTROL VALVE (See page 13-2 )
NG REPLACE INTAKE AIR CONTROL VALVE
OK
REPLACE ECM (See page 10-24 )
OBD II scan tool (excluding hand-held tester):
1 INSPECT VSV FOR IAC VALVE NO.2 (OPERATION)
(a) Air (a) Disconnect the VSV connector.
(b) Check operation of the VSV when battery positive voltage
is applied to the terminals of the VSV.
Air Filter
OK:
Port E
Battery positive voltage is not applied:
Air from port E flows out through the air filter.
Battery positive voltage is applied:
Air from port E flows out through port F.
(b)
Air
Port E
Battery
Y Port F
A54315
A54316 A87791 NG REPLACE VSV
OK
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 854
05-665
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
2 CHECK ECM (ACIS VOLTAGE)
(a) Start the engine.
E1 (-) (b) Check the voltage of the ECM connectors.
Standard
Tester Connection Condition Specified Condition
Engine speed is 4,000
E7-15 (ACIS) rpm or less
9 to 14 V
- E9-1 (E1) Throttle valve opening
ACIS (+)
angle is 30 or more
E7 E9
ECM ECM A76903
OK Go to step 4
NG
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 855
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DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
3 CHECK WIRE HARNESS (VSV FOR IAC VALVE NO. 2 - ECM, VSV FOR IAC VALVE
NO.2 - EFI RELAY)
(a) Check the wire harness between the VSV and ECM.
Wire Harness Side
(1) Disconnect the V2 VSV connector.
V2
(2) Disconnect the E7 ECM connector.
VSV for IAC Valve No. 2
(3) Check the resistance of the wire harness side con-
nectors.
Standard:
Tester Connection Specified Condition
V2-2 - E7-15 (ACIS) Below 1 Ω
V2-2 or E7-15 (ACIS) - Body ground 10 kΩ or higher
E7
ECM
Y
ACIS
A85675
A81699 A87763
Wire Harness Side (b) Check the wire harness between the VSV and EFI relay.
V2
(1) Disconnect the V2 VSV connector.
VSV for IAC Valve No. 2 (2) Remove the EFI relay from the engine room J/B.
(3) Check the resistance OF the wire harness side con-
nectors.
Standard:
Tester Connection Specified Condition
V2-1 (VSV for ACIS) - J/B EFI relay terminal 3 Below 1 Ω
Engine Room J/B
EFI Relay
A85448
A90291 A92391 NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 856
05-667
DIAGNOSTICS - SFI SYSTEM (3MZ-FE)
4 CHECK VACUUM HOSES (INTAKE MANIFOLD - INTAKE AIR CONTROL VALVE,
INTAKE AIR CONTROL)
(a) Check that the vacuum hoses are:
Connected correctly.
Are not loose or disconnected.
Do not have cracks, holes or damage.
NG REPAIR OR REPLACE VACUUM HOSE
OK
5 INSPECT INTAKE AIR CONTROL VALVE (See page 13-2 )
NG REPLACE INTAKE AIR CONTROL VALVE
OK
REPLACE ECM (See page 10-24 )
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
Author: Date: 857
