2005 HIGHLANDER (EWD592U)
80
Engine Control for 3MZ-FE
A
AB
B
9TAC
4G 1A 2
WBA
1B
16 75
IC21 IL2MPX1
74L 114L54F
R SB
14N 64C7
1IL2
B 2 12 IL2
GR1
74F
8IB2
1IB2
5IF3
B 68
10 A 10 1E7. 5A
OBD
MPX+ MPX2
W
MPX2
MPX1
W- B
W- B
B
GR O
SB GR
SC SIL BAT
CG
4
W- B
V
G Y OGR
P 5
LY
SB
Y
L O 2B P
4AP
54H
W- B
D
D
15
J16
5
WFSE13
TC
P
11MPD14
MPD2 D 3G 5G
MPX-
V
9A
GV
O
R
W
R
O
V
P
W- B
B
Y
BR BR
BR
22MPX2
24MPX1 A17
(
*2)
(
*1) (
*1)
3E 1
3J 12
GY
* 1 : w/ Navigation System
* 2 : w/o Navigation System From Power Sour ce System (
See Page 62)
S30(
A)
, S31(
B)
A10(
A)
, A11(
B) B 9(
A)
, B10(
B)
A/C Control
Assembly
Airbag Sensor Assembly
Body ECU
Data Link Connector 3
Gateway ECUJunction
Connector
Power Window Master SW
with ECU
Short Connector
2005 HIGHLANDER (EWD592U)
82
Engine Control for 3MZ-FE
The engine control system utilizes a microcomputer and maintains overall control of the engine, transmission etc. An outline
of the engine control is given here.
1. Input Signals
(1) Engine coolant temp. signal circuit
The engine coolant temp. sensor detects the engine coolant temp. and has a built-in thermistor with a resistance, which
varies according to the engine coolant temp. The engine coolant temp. which is input into TERMINAL THW of the
engine control module as a control signal.
(2) Intake air temp. signal circuit
The intake air temp. sensor is installed in the mass air flow meter and detects the intake air temp. which is input as a
control signal to TERMINAL THA of the engine control module.
(3) Vehicle speed signal circuit
The vehicle speed signal is input from the ABS speed sensor to skid control ECU with actuator, and are sent to the
engine control module through communication control.
(4) RPM signal circuit
Camshaft position is detected by the VVT sensors and its signal is input to TERMINALS VV1+ and VV2+ of the engine
control module as a control signal. Also, engine RPM is detected by the crankshaft position sensor and is input as a
control signal to TERMINAL NE+.
(5) Throttle position signal circuit
The throttle control motor and sensor detects the throttle valve opening angle as a control signal, which is input into
TERMINALS VTA1 and VTA2 of the engine control module.
(6) Battery signal circuit
Voltage is constantly applied to TERMINAL BATT of the engine control module. With the ignition SW turned on, the
voltage for engine control module start-up power supply is applied to TERMINALS +B and +B2 of the engine control
module via the EFI relay.
The current flowing through the IGN fuse flows to TERMINAL IGSW of the engine control module.
(7) Intake air volume signal circuit
Intake air volume is detected by the mass air flow meter and the signal is input to TERMINAL VG of the engine control
module as a control signal.
(8) Stop light SW signal circuit
The stop light SW is used to detect whether the vehicle is braking or not and the signal is input into TERMINAL STP of
the engine control module as a control signal.
(9) Starter signal circuit
To confirm whether the engine is cranking, the voltage is applied to the starter motor during cranking is detected and the
signal is input into TERMINAL STA of the engine control module as a control signal.
(10) Engine knock signal circuit
Engine knocking is detected by knock sensors and the signal is input into TERMINALS KNK1 and KNK2 as a control
signal.
(11) Air fuel ration signal circuit
The air fuel ration is detected and input as a control signal into TERMINALS A1A+ and A2A+ of the engine control
module.
(12) Oxygen sensor signal circuit
The oxygen density in the exhaust gases is detected and input as a control signal into TERMINALS OX1B and OX2B of
the engine control module.
To maintain stable detection performance by the heated oxygen sensor, a heater is used for warning the sensor. The
heater is also controlled by the engine control module (HT1B and HT2B).
(13) Fuel cut in a collision
The system receives the collision signal from airbag sensor assembly in the vehicle has a collision and stops the fuel
pump operation on the side of the engine control module.
System Outline
2005 HIGHLANDER (EWD592U)
83
2. Control System
*SFI system
The SFI system monitors the engine condition through the signals input from each sensor (Input signals from (1) to (12)
etc.) to the engine control module. And the control signal is output to TERMINALS #10, #20, #30, #40, #50 and #60 of
the engine control module to operate the injector (Inject the fuel). The SFI system controls the fuel injection operation by
the engine control module in response to the driving conditions.
*ESA system
The ESA system monitors the engine condition through the signals input to the engine control module from each sensor
(Input signals from (1) to (12) etc.). The best ignition timing is decided according to this data and the memorized data in
the engine control module and the control signal is output to TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5 and IGT6. This
signal controls the igniter to provide the best ignition timing for the driving conditions.
*ACIS
The ACIS includes a valve in the bulkhead separating the surge tank into two parts. This valve is opened or closed
according to the driving conditions to control the intake manifold length in three stages, for increased engine output in all
ranges from low to high speeds, when idling.
3. Diagnosis System
With the diagnosis system, when there is a malfunction in the engine control module signal system, the malfunctioning
system is recorded in the memory. The malfunctioning system can be found by reading the code displayed by the
malfunction indicator lamp.
4. Fail-Safe System
When a malfunction has occurred in any system, if there is a possibility of engine trouble being caused by continued control
based on the signals from that system, the fail-safe system either controls the system by using data (Standard values)
recorded in the engine control module memory or else stops the engine.
CIRCUIT OPENING Relay
5-3 : Closed with the starter running
EFI Relay
5-3 : Closed with the ignition SW at ON or ST position
E5 (A), E6 (B), E7 (E), E8 (D), E9 (C) Engine Control Module
Voltage at engine control module wiring connector
BATT-E1 : Always 9.0-14.0 volts
VC-E2 : Always 4.5-5.5 volts (Ignition SW at ON position)
VG-E2G : 1.1-1.5 volts (Engine idling and A/C SW off)
THA-E2 : 0.5-3.4 volts (Engine idling and intake air temp. 20°C, 68°F)
THW-E2 : 0.2-1.0 volts (Engine idling and coolant temp. 80°C, 176°F)
IGF-E1 : 4.5-5.5 volts (Ignition SW at ON position)
Pulse generation (Engine idling)
SIL-E1 : Pulse generation (During transmission)
TACH-E1 : Pulse generation (Engine idling)
STA-E1 : 6.0 volts or more (Engine cranking)
FC-E1 : 9.0-14.0 volts (Ignition SW at ON position)
0-3.0 volts (Engine idling)
SPD-E1 : Pulse generation (Ignition SW on and rotate driving wheel slowly)
W-E1 : Below 3.0 volts (Ignition SW at ON position)
NSW-E1 : 9.0-14.0 volts (Ignition SW on and other shift position in P or N position)
0-3.0 volts (Ignition SW on and shift position in P or N position)
PRG-E01 : 9.0-14.0 volts (Ignition SW at ON position)
TC-E1 : 9.0-14.0 volts (Ignition SW at ON position)
STP-E1 : 7.5-14.0 volts (Ignition SW on and brake pedal depressed)
0-1.5 volts (Ignition SW on and brake pedal depressed)
PTNK-E1 : 3.0-3.6 volts (Ignition SW at ON position)
1.3-2.1 volts (Ignition SW on and apply vacuum 2.0 kpa)
OX1B, OX2B-E1 : Pulse generation (Maintain engine speed at 2500 rpm for two minutes after warming up)
KNK1, KNK2-E1 : Pulse generation (Engine idling)
IGT1, IGT2, IGT3, IGT4, IGT5, IGT6-E1 : Pulse generation (Engine idling)
#10, #20, #30, #40, #50, #60-E01 : 9.0-14.0 volts (ignition SW at ON position)
Pulse generation (Engine idling)
Service Hints