1994 TOYOTA CAMRY system

78
ENGINE CONTROL (1MZ±FE)
THIS SYSTEM UTILIZES AN ENGINE CONTROL MODULE (ENGINE AND ELECTRONIC CONTROLLED TRANSMISSION ECU) AND
MAINTAINS OVERALL CONTROL OF THE ENGINE, TRANSMISSION AND SO ON. AN OUTLINE OF THE ENGINE CONTROL IS
EXPLAINED HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. (WATER TEMP.) SIGNAL CIRCUIT
THE ENGINE COOLANT TEMP. SENSOR (WATER TEMP. SENSOR) DETECTS THE ENGINE COOLANT TEMP. AND HAS A
BUILT±IN THERMISTOR WITH A RESISTANCE WHICH VARIES ACCORDING TO THE WATER TEMP. IS INPUT INTO TERMINAL
THW OF ENGINE CONTROL MODULE (ECU) AS A CONTROL SIGNAL.
(2) INTAKE AIR TEMP. SIGNAL CIRCUIT
THE INTAKE AIR TEMP. SENSOR IS INSTALLED IN THE MASS AIR FLOW (AIR FLOW METER) AND DETECTS THE INTAKE AIR
TEMP., WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA OF ENGINE CONTROL MODULE (ECU).
(3) OXYGEN SENSOR SIGNAL SYSTEM
THE OXYGEN DENSITY IN THE EXHAUST GASES IS DETECTED AND INPUT AS A CONTROL SIGNAL TO TERMINAL OXL, OXR
AND OXS OF THE ENGINE CONTROL MODULE (ECU). TO MAINTAIN STABLE DETECTION PERFORMANCE BY THE OXYGEN
SENSOR, A HEATER IS USED FOR WARMING THE SENSOR. THE HEATER IS ALSO CONTROLLED BY THE ENGINE CONTROL
MODULE (ECU) (HTL, HTR AND HTS).
(4) RPM SIGNAL SYSTEM
CAMSHAFT POSITION AND CRANKSHAFT POSITION ARE DETECTED BY THE CAMSHAFT POSITION SENSOR AND
CRANKSHAFT POSITION SENSOR. CRANKSHAFT POSITION IS INPUT AS A CONTROL SIGNAL TO TERMINAL G22+ OF THE
ENGINE CONTROL MODULE (ECU), AND ENGINE RPM IS INPUT TO TERMINAL NE+.
(5) THROTTLE SIGNAL CIRCUIT
THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE AS A CONTROL SIGNAL, WHICH IS
INPUT INTO TERMINAL VTA OF THE ENGINE CONTROL MODULE (ECU). WHEN THE VALVE IS COMPLETELY CLOSED, THE
CONTROL SIGNAL IS INPUT INTO TERMINAL IDL.
(6) VEHICLE SPEED SIGNAL SYSTEM
THE VEHICLE SPEED SENSOR (SPEED SENSOR), INSTALLED INSIDE THE COMBINATION METER, DETECTS THE VEHICLE
SPEED AND INPUTS A CONTROL SIGNAL TO TERMINAL SP1 OF THE ENGINE CONTROL MODULE (ECU).
(7) PARK/NEUTRAL POSITION SW (NEUTRAL START SW) SIGNAL SYSTEM
THE PARK/NEUTRAL POSITION SW (NEUTRAL START SW) DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR
PARKING OR NOT, AND INPUTS A CONTROL SIGNAL TO TERMINAL NSW OF THE ENGINE CONTROL MODULE (ECU).
(8) A/C SW SIGNAL SYSTEM
THE A/C AMPLIFIER INPUTS THE A/C OPERATIONS TO TEMRINAL A/C OF THE ENGINE CONTROL MODULE (ECU) AS A
CONTROL SIGNAL.
(9) BATTERY SIGNAL CIRCUIT
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE (ECU). WHEN THE IGNITION SW
TURNED ON, VOLTAGE FOR ENGINE CONTROL MODULE (ECU) START±UP POWER SUPPLY IS APPLIED TO TERMINALS +B
AND +B1 OF ENGINE CONTROL MODULE (ECU) VIA EFI MAIN RELAY.
(10) INTAKE AIR VOLUME SIGNAL CIRCUIT
INTAKE AIR VOLUME IS DETECTED BY THE MASS AIR FLOW (AIR FLOW METER) AND THE SIGNAL IS INPUT TO TERMINAL VG
OF THE ENGINE CONTROL MODULE (ECU). AS A CONTROL SIGNAL.
(11) STA SIGNAL CIRCUIT
TO CONFIRM WHETHER THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL STA OF THE ENGINE CONTROL MODULE (ECU) AS A CONTROL
SIGNAL.
(12) ENGINE KNOCK SIGNAL CIRCUIT
ENGINE KNOCKING IS DETECTED BY THE KNOCK SENSOR NO. 1 AND NO. 2 AND THE SIGNALS ARE INPUT INTO TERMINALS
KNKR AND KNKL AS A CONTROL SIGNAL.
SYSTEM OUTLINE

79
2. CONTROL SYSTEM
*SFI (SEQUENTIAL MULTIPORT FUEL INJECTION) (EFI (ELECTRONIC FUEL INJECTION) SYSTEM
THE EFI SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS
FROM (1) TO (12) ETC.). THE BEST FUEL INJECTION VOLUME IS DECIDED BASED ON THIS DATA AND THE PROGRAM MEMORIZED
BY THE ENGINE CONTROL MODULE (ECU), AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, #40, #50 AND #60
OF THE ENGINE CONTROL MODULE (ECU) TO OPERATE THE INJECTOR (INJECT THE FUEL). THE EFI SYSTEM PRODUCES
CONTROL OF FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ECU) IN RESPONSE TO THE DRIVING
CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE (ECU)
FROM EACH SENSOR (INPUT SIGNALS FROM (1), (3), (4) TO (12) ETC.). THE BEST IGNITION TIMING IS DECIDED ACCORDING TO
THIS DATA AND THE MEMORIZED DATA IN THE ENGINE CONTROL MODULE (ECU) AND THE CONTROL SIGNAL IS OUTPUTS TO
TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5 AND IGT6. THIS SIGNAL CONTROLS THE IGNITER TO PROVIDE THE BEST IGNITION
TIMING FOR THE DRIVING CONDITIONS.
*HEATED OXYGEN SENSOR (OXYGEN SENSOR) HEATER CONTROL SYSTEM
THE OXYGEN SENSOR HEATER CONTROL SYSTEM TURNS THE HEATER ON WHEN THE INTAKE AIR VOLUME IS LOW (TEMP. OF
EXHAUST EMISSIONS IS LOW), AND WARMS UP THE OXYGEN SENSOR (NO. 1 AND NO. 2) TO IMPROVE DETECTION
PERFORMANCE OF THE SENSOR.
THE ENGINE CONTROL MODULE (ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9) TO (10)
ETC.), AND OUTPUT CURRENT TO TERMINALS HTL, HTR AND HTS AND CONTROL THE HEATER.
*IAC (IDLE AIR CONTROL (ISC)) SYSTEM
THE IAC (ISC) SYSTEM (ROTARY SOLENOID TYPE) INCREASES THE RPM AND PROVIDES IDLE STABILITY FOR FAST IDLE±UP
WHEN THE ENGINE IS COLD, AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL LOAD AND SO ON, THE ENGINE
CONTROL MODULE (ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9) ETC.),
OUTPUTS CURRENT TO TERMINALS RSO AND RSC TO CONTROL IDLE AIR CONTROL VALVE.
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10), ETC)., AND
OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*ACIS (ACOUSTIC CONTROL INDUCTION SYSTEM)
ACIS INCLUDES A VALVE IN THE BULKHEAD SEPARATING THE SURGE TANK INTO TWO PARTS. THIS VALVE IS OPENED AND
CLOSED IN ACCORDANCE WITH THE DRIVING CONDITIONS TO CONTROL THE INTAKE MANIFOLD LENGTH IN TWO STAGES FOR
INCREASED ENGINE OUTPUT IN ALL RANGES FROM LOW TO HIGH SPEEDS.
THE ENGINE CONTROL MODULE (ECU) JUDGES THE ENGINE SPEED BY THE SIGNALS ((4), (5)) FROM EACH SENSOR AND
OUTPUTS SIGNALS TO THE TERMINAL ACIS TO CONTROL THE VSV (FOR OPENING AND CLOSING THE INTAKE CONTROL VALVE)
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE (ECU) SIGNAL SYSTEM, THE
MALFUNCTIONING SYSTEM IS RECORDED IN THE MEMORY.
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 (ECU) MEMORY OR ELSE STOPS THE
ENGINE.

80
ENGINE CONTROL (1MZ±FE)
AM1
AM2 104
7
9 ST1
IG2
2G 1
IG 1 2
1 2
1 2
1 2
1 2
1 2 I20
E12 I18 E12 I18
BX1 4IJ1 16 EF1 3IP1 9IP1 16
IP3 15 66
666 641 32 2H 2
L±B
G±R
Y
R
L
GR
G
W B±OL±B B±W
B±WB±O
B±O B±O B±O
BB±O
BWW
BW
W±R
B±O
B±O B±O B±O
B±O
B±O
B±O
B±O
B±O Y RL GRG W
W±B W±B W±B
L±B L±BG±R
L±BB± O
B±W
B±W
BATTERY FL MAIN
2. 0LI18
B±O B±O 100A ALT
10A
STARTER
30A
AM2
FUSE BOX
IGNITION SW
CIRCUIT
OPENING
RELAY
INJECTOR NO. 1
INJECTOR NO. 6
INJECTOR NO. 3
INJECTOR NO. 4
INJECTOR NO. 5
INJECTOR NO. 2 I4
I9
I6
I7
I8
I5
I12
L±B
A 1
B 1B F10 , F16A
FROM POWER SOURCE
SYSTEM(
SEE PAGE 64)
1 B±O
B±W B±W
B±O
IP14
B±O 4
1G 9
1E 140A
AM1 2
1
1G 8
1A 67. 5A
IGN 1D 9
3B 20
3D 23C 2
3A 13
1C 113C 18
1M 1

81
A
M 45
BL EBBX15 D 14
BATT
D 21
ELSA 14
NSWA 13
STA
D 23+B
D 22+B1
A 9#20
A 6#50
A 7#40
A 8#30
A 5#60
A 10#10 2B 22C32D4
IP3 12 I18
I23
L± B
G±R
Y
R
L
GR
G
W B± O B± OL± B B±W
B±WB± O
L±B B±O
B±O
B±O
G±R
W± B
B±O
W±G W±L
B±R
B±W
B±W B±OB±O B±O
W±BB±O
B±O
Y
R
L
GR
G
W
W±B F15
FUEL PUMPENGINE CONTROL MODULE
(
ENGINE AND ELECTRONIC
CONTROLLED TRANSMISSION ECU) 25 13
E7 , E8 ,E9 , E10 D
BC
IP120
B±W
I23
L±B 15A
EFIFROM POWE
G G
P
2 3
1 2D 2 IP1 18
DIODE
(
FOR IDLE±UP) D6
B±O
W±BB±O
B±O
EF1 1
IP3 18
B±W
B±WB±O
I18 E10 E12 E11
1 2
2 1
2 1
2 1
2 1
3
A 23
RSOA 22
RSCC 1
ACVC 12
EGRA 25
FPUC 6
ACIS AA A
B± O B±O
B±O
B±O
B±O
B±O G±B
Y± B
W±L
B±L
B±R
R±Y
JUNCTION
CONNECTOR J6 B±O B±O
B±O B±O B±O
ILDE AIR CONTROL VALVE
(
ISC VALVE)
VSV
(
FOR A/C IDLE±UP)
VSV
(
FOR EGR)
VSV
(
FOR FUEL PRESSURE UP)
VSV
(
FOR INTAKE AIR CONTROL) I1
V1
V2
V3
V4EFI MAIN
RELAY
IP111
1G 6
1E 5 1DA
MIR±
HTR
1A 14 10
3C 53D 5TA I L
R SOURCE SYSTEM(
SEE PAGE 64)
10
15A

83
AB
A
EC 1 C 5
TE 1D 11
TE2
B 14KNKL
B 16G22+
B 5NE +
EE1 4EE12
1 1
BR
B
B±O
L±B
BR GR±B
WB
B±W
R R B±W
3 1 12 19
8FP +B IG±
SG
TE 2 TE 1 DATA LINK CONNECTOR
1(
CHECK CONNECTOR) D1
V5
CRANKSHAFT POSITION
SENSOR C18KNOCK SENSOR 2 K2
CAMSHAFT POSITION
SENSOR C17
C 3
G±R
6B 3
G±R
A
W
(
SHIELDED) (
SHIELDED)
D 12FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
C CIP3 2
IP2 11 IP2141
23
4 512 SP1G±B
GLGP
R±LR±L
R±L
VEHICLE SPEED
SENSOR
(
SPEED SENSOR)
B
MALFUNCTION INDICATOR LAMP
(
CHECK ENGINE WARNING LIGHT)
[COMB. METER] C9 , C10
SPEED
JUNCTION
CONNECTOR J2 COMBINATION
METER C8
D
E NG INE CO NTROL MODULE(
ENGINE AND ELECTRONIC
CONTROLLED TRANSMISSION ECU) E7 , E8 ,E9 ,E10C
E142 1
NOISE FILTER
(
FOR IGNITION
SYSTEM) W±B
W±B B±O
W±B
N1
V±Y
ED B±OR±L
R±L B
I23
D 28
SDL DA TA LINK
CO NNE CTOR 3 D24 FROM POWER
SO TEM
(
S)
.5A
OBD
DA TA LINK
CO NNE CTO R
2(
TDCL) D3
IP3 16 IP1 1
22I18 I18B 6NE±
C E1
I18 IM12
J1
J UNCTION CO NNE CTO R
IE JUNCTION
CONNECTOR J7
L
G
BR
V±Y L
G
V±Y
BR BR W±B
W±B
BR
BR
BR BR BR BR
G (
SHIELDED)
(
SHIELDED)
(
SHIELDED)
(
SHIELDED)
A
A
A
AA
A
A
A
A
A
A
BR
BR
BR
BR
BR
W±B BR
BR
BRBR
(
SHIELDED)
(
SHIELDED) BR BR
BR
BR BR W±B
F F
24 15
2 45
G± WBR W±B
L±B
B±O
BR
BR
BR
BR BB G±W
W3
E1
OX1
SDL
16W±BE1
CG
OX2
BATT(
SHIELDED)
(
SHIELDED) BR
(
SHIELDED)
(
SHIELDED)
(
SHIELDED)
(
SHIELDED)
16 B 17G22±IP1 19
G±R
10A
GAUGE
1B 616
R± L
D
3D 3
3D 12
3D 183D 7
3D 3
3D 22
3D 10
1M5
1C8
URCE SYS
EE PAGE 64
7

88
ENGINE CONTROL (5S±FE)
THIS SYSTEM UTILIZES AN ENGINE CONTROL MODULE (ENGINE ECU (M/T), ENGINE AND ELECTRONIC CONTROLLED
TRANSMISSION ECU (A/T)) AND MAINTAINS OVERALL CONTROL OF THE ENGINE, TRANSMISSION AND SO ON. AN OUTLINE OF THE
ENGINE CONTROL IS EXPLAINED HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. (WATER TEMP.) SIGNAL SYSTEM
THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP. SENSOR) DETECTS THE ENGINE COOLANT TEMP. AND HAS A
BUILT±IN THERMISTOR WITH A RESISTANCE WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP. (WATER TEMP.)
THUS THE ENGINE COOLANT TEMP. (WATER TEMP.) IS INPUT IN THE FORM OF A CONTROL SIGNAL TO TERMINAL THW OF
THE ENGINE CONTROL MODULE (ECU).
(2) INTAKE AIR TEMP. SIGNAL SYSTEM
THE INTAKE AIR TEMP. SENSOR (IN±AIR TEMP. SENSOR) IS DETECTS THE INTAKE AIR TEMP., WHICH IS INPUT AS A
CONTROL SIGNAL TO TERMINAL THA OF THE ENGINE CONTROL MODULE (ECU).
(3) OXYGEN SENSOR SIGNAL SYSTEM
THE OXYGEN DENSITY IN THE EXHAUST GASES IS DETECTED AND INPUT AS A CONTROL SIGNAL TO TERMINAL OX1 AND
OX2 OF THE ENGINE CONTROL MODULE (ECU).
(4) RPM SIGNAL SYSTEM
CRANKSHAFT POSITION AND ENGINE RPM ARE DETECTED BY THE PICK±UP COIL INSTALLED INSIDE THE DISTRIBUTOR.
CRANKSHAFT POSITION IS INPUT AS A CONTROL SIGNAL TO TERMINALS G+ AND G2 (CALIFORNIA), OF THE ENGINE
CONTROL MODULE (ECU), AND RPM IS INPUT TO TERMINAL NE+.
(5) THROTTLE SIGNAL SYSTEM
THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE, WHICH IS INPUT AS A CONTROL
SIGNAL TO TERMINAL VTA OF THE ENGINE CONTROL MODULE (ECU), OR WHEN THE VALVE IS FULLY CLOSED, TO
TERMINAL IDL
(6) VEHICLE SPEED SIGNAL SYSTEM
THE VEHICLE SPEED SENSOR (SPEED SENSOR), INSTALLED INSIDE THE COMBINATION METER, DETECTS THE VEHICLE
SPEED AND INPUTS A CONTROL SIGNAL TO TERMINAL SPD OF THE ENGINE CONTROL MODULE (ECU).
(7) PARK/NEUTRAL POSITION SW (NEUTRAL START SW) SIGNAL SYSTEM (A/T)
THE PARK/NEUTRAL POSITION SW (NEUTRAL START SW) DETECTS WHETHER THE SHIFT POSITION ARE IN NEUTRAL AND
PARKING OR NOT, AND INPUTS A CONTROL SIGNAL TO TERMINAL NSW OF THE ENGINE CONTROL MODULE (ECU).
(8) A/C SW SIGNAL SYSTEM
THE A/C AMPLIFIER INPUTS THE A/C OPERATIONS TO TARMINAL ACA OF THE ENGINE CONTROL MODULE (ECU) AS A
CONTROL SIGNAL.
(9) BATTERY SIGNAL CIRCUIT
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE (ECU). WHEN THE IGNITION SW
TURNED ON, THE VOLTAGE FOR ENGINE CONTROL MODULE (ECU) START±UP POWER SUPPLY IS APPLIED TO TERMINALS
+B AND +B1 OF ENGINE CONTROL MODULE (ECU) VIA EFI MAIN RELAY. THE CURRENT FLOWING THROUGH THE IGN FUSE
FLOWS TO TERMINAL IGSW OF THE ENGINE CONTROL MODULE (ECU).
(10) INTAKE AIR VOLUME SIGNAL SYSTEM
INTAKE AIR VOLUME IS DETECTED BY THE MANIFOLD ABSOLUTE PRESSURE SENSOR (VACUUM SENSOR) (FOR MANIFOLD
PRESSURE) AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL PIM OF THE ENGINE CONTROL MODULE (ECU).
(11) STA SIGNAL CIRCUIT
TO CONFIRM WHETHER THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL STA OF THE ENGINE CONTROL MODULE (ECU) AS A CONTROL
SIGNAL.
(12) ENGINE KNOCK SIGNAL CIRCUIT
ENGINE KNOCKING IS DETECTED BY KNOCK SENSOR AND THE SIGNAL IS INPUT INTO TERMINAL KNK AS A CONTROL
SIGNAL.
(13) ELECTRICAL LOAD SIGNAL SYSTEM
THE SIGNAL WHEN SYSTEMS SUCH AS THE REAR WINDOW DEFOGGER, HEADLIGHTS, ETC. WHICH CAUSE A HIGH
ELECTRICAL BURDEN ARE ON IS INPUT TO TERMINAL ELS AS A CONTROL SIGNAL.
SYSTEM OUTLINE

89
2. CONTROL SYSTEM
*MFI (MULTIPORT FUEL INJECTION (EFI)) SYSTEM
THE MFI (EFI) SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT
SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL MODULE (ECU). THE BEST FUEL INJECTION VOLUME IS DECIDED
BASED ON THIS DATA AND THE PROGRAM MEMORIZED BY THE ENGINE CONTROL MODULE (ECU), AND THE CONTROL SIGNAL
IS OUTPUT TO TERMINALS #10, #20, #30 AND #40 (CALIFORNIA), TERMINALS #10 AND #20 (EX. CALIFORNIA) OF THE ENGINE
CONTROL MODULE (ECU) TO OPERATE THE INJECTOR. (INJECT THE FUEL). THE MFI (EFI) SYSTEM PRODUCES CONTROL OF
FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ECU) IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE (ECU)
FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO (12) ETC.) THE BEST IGNITION TIMING IS DETECTED ACCORDING TO
THIS DATA AND THE MEMORIZED DATA IN THE ENGINE CONTROL MODULE (ECU) AND THE CONTROL SIGNAL IS OUTPUT TO
TERMINAL IGT. THIS SIGNAL CONTROLS THE IGNITER TO PROVIDE THE BEST IGNITION TIMING FOR THE DRIVING CONDITIONS.
*IAC (IDLE AIR CONTROL (ISC)) SYSTEM
THE IAC (ISC) SYSTEM (ROTARY SOLENOID TYPE) INCREASES THE RPM AND PROVIDES IDLING STABILITY FOR FAST IDLE±UP
WHEN THE ENGINE IS COLD AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL LOAD, ETC. THE ENGINE
CONTROL MODULE (ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS (1), (4) TO (8), (13) ETC.), OUTPUTS
CURRENT TO TERMINALS ISCO AND ISCC, AND CONTROLS THE IDLE AIR CONTROL VALVE (ISC VALVE).
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE (ECU) OPERATION OUTPUTS TO TERMINAL FC AND CONTROLS THE CIRCUIT OPENING RELAY
AND THUS CONTROLS THE FUEL PUMP DRIVE SPEED IN RESPONSE TO CONDITIONS.
*A/C IDLE±UP SYSTEM
IN ORDER TO PREVENT THE ENGINE IDLING SPEED FROM DROPPING WHEN THE A/C IS OPERATING, THE A/C IDLE±UP SYSTEM
CONTROLS THE VSV (FOR A/C IDLE±UP) TO INCREASE THE ENGINE IDLING SPEED AND KEEP IT STABLE.
*EGR CONTROL SYSTEM
THE EGR CUT CONTROL SYSTEM CONTROLS THE VSV (FOR EGR) BY EVALUATING THE SIGNALS FROM EACH SENSOR INPUT TO
THE ENGINE CONTROL MODULE (ECU) (INPUT SIGNALS (1), (5), (6), (9) ETC.) AND BY SENDING OUTPUT TO TERMINAL THG OF
THE ENGINE CONTROL MODULE (ECU).
*A/C CUT CONTROL SYSTEM
WHEN THE VEHICLE SUDDENLY ACCELERATES FROM LOW ENGINE SPEED, THIS SYSTEM CUTS OFF AIR CONDITIONING
OPERATION FOR A FIXED PERIOD OF TIME IN RESPONSE TO THE VEHICLE SPEED AND THROTTLE VALVE OPENING ANGLE IN
ORDER TO MAINTAIN ACCELERATION PERFORMANCE.
THE ENGINE CONTROL MODULE (ECU) RECEIVES INPUT SIGNALS ((5), (6) ETC.), AND OUTPUTS SIGNALS TO TERMINAL ACT.
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTIONING IN THE ENGINE CONTROL MODULE (ECU) SIGNAL SYSTEM,
THE MALFUNCTION SYSTEM IS RECORDED IN THE MEMORY. THE MALFUNCTIONING SYSTEM CAN THEN BE FOUND BY READING
THE DISPLAY (CODE) OF THE MALFUNCTION INDICATOR LAMP (CHECK ENGINE WARNING LIGHT).
4. FAIL±SAFE SYSTEM
WHEN A MALFUNCTION OCCURS 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 (ECU) MEMORY OR ELSE STOPS THE
ENGINE.

90
ENGINE CONTROL (5S±FE A/T AND CALIFORNIA M/T)
CB
IG2
ACC
IG1 ST2AM2
AM1
ST1
7 9
1 2
1 2
1 2
1 2 E20
E20
E20I20
I23 E20 E18 E18 E17E17
I18
EBA 1A 12
A 22 C 11 C12A23 C 7 IP 3 12
1 2
2 1 2D 2
2B 22C3
W±B
B±W B±WY
B±W
Y WW±R
W±R
W±R
W±RW±R W±R W±R W±R B±O
B±W
B±O
W±G
B±O B±O
B±O B±O B±OLG
G W±L W±B B±W
W±R
B±O B±O B±O W±R
B±O B±O B±O
B±O
7. 5A
IGN
IP1 18
B±O
#20 #10 NSWBATT EGRISCV +B 15A
EFI
EFI MAIN
RELAY
VSV
(
FOR EGR) VSV
(
FOR A/C IDLE±UP)
E NGINE CONTROL MODULE(
ENGINE AND ELECTRONIC
CONTROLLED TRANSMISSION ECU)(
A/T)
INJE CTOR NO. 1
INJE CTOR NO. 3
INJE CTOR NO. 2
INJE CTOR NO. 4 I4
I5
I6
I7
E7 , E8 , E10C
V2 V1
W±R
I12
IGNITION SW
C 9C10 31 2
B±O
G±Y G±R
ISCC ISCO
IDLE AIR CONTROL
VALVE
(
ISC VALVE) I1
FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
34 13
IP1 11
IP1 9
W±R
B±O (
*4) (
*5)
TO PARK/NEUTRAL POSITION SW
(
NEUTRAL STA RT SW) 2D 4IP116
W±R
I2 C 24#40
I18C 25#30
W W(
*1)
(
*2)
(
*2)
Y
(
*2)
Y
(
*1)
R±B(
*1)
(
*2)
Y(
*1)
W(
*2)
W(
*1)
R±L(
*1)
B±W
(
*5)
E17
B±O B±O
(
*2)
(
*1) (
*1)
B±O
(
*1)
12
25(
*1)
(
*2)
(
*1)
(
*2)
B±W
W
(
*2)
(
EX. CALIFORNIA M/T)
(
EX. CALIFORNIA M/T)B E11 , E12CA,E14E NGINE CONTROL MODULE(
ENGINE ECU)(
M/T)
I21
B±W
(
*4)
B±W
1A 61G 8
1D 9
1G 61E 51A14