1994 TOYOTA CAMRY ECU

68
STARTING AND IGNITION (1MZ±FE)
A
AM1
AM2 104
7
9 ACC
IG1
ST1
IG2
ST2
EF1 3EF1 1 1 2G 1
1
2H 2
IG M
B 1
B1
B±RB±R
B±R B±O B±WB±O
B
BWW
W±RW
B±R B±R
W±B
B
B±W B
W±B W±B
B±W
IGNITION SW
52 31
B±W 100A ALT
FUSE BOX
30A
AM210A
STARTER
STARTER
RELAY
PARK/NEUTRAL POSITION SW
(
NE UTRA L START SW)
STARTER BATTERY FL MAIN
2. 0L
S3 , S4 I12
P1
AP
N5
6
B
A 1
B 1
B F10 , F16A
E10 17 2C52F12C2
TO CIRCUIT OPENING
RELAY TO ENGINE CO NTROL
MODULE(
ENGINE AND
ELECTRONIC CONTROLLED
TRANSMISSION ECU)B±W
B±W
5
4 40A
MAIN
IP1
B±W
1E 51G 6
1C 113C 6
1M 13C 18
3C 2
3D 2 3B 20
1G 9
1E 140A
AM1 2
1

69
IP1 16
W±R B±O
B±O
B±O
TO NOISE FILTER
(
FOR IGNITION SYSTEM)
E14 E12 E14 E13 E13 E13
2 1
2 1
2 1
2 1
2 1
2 1
A 1A2A3A4A5A6A7
B 8B6B5B4B3B2B1B7A8
A A
ED EC IGF IGT1 IGT2
12 24 16 15 26 30 29
IGF IGT1 IGT2 IGT4IGT3 IGT5 IGT6 +B COIL1 COIL2 COIL3 COIL4 COIL5 COIL6
IGT3 IGT4 IGT5 IGT6 TACHGND
L
GR
W
G
LG ±B
PB±O
B±O
B±O
B±O
B±O
B±O W±R
W±G
Y±R
GR±B
L±B
R±B
G±R
B BR BRW± B
B±O B±O B±O B± OB±O
B±O
19
3IG±
E1
E7D1
J7 ENGINE CONTROL MODULE(
ENGINE AND
ELECTRONIC CONTROLLED TRANSMISSION ECU)
JUNCTION
CONNECTORDATA LINK
CONNECTOR 1
(
CHECK
CONNECTOR)
IGNITON COIL NO. 1
IGNITON COIL NO. 2
IGNITON COIL NO. 3
IGNITON COIL NO. 4
IGNITON COIL NO. 5
IGNITON COIL NO. 6
B I2 ,I15A
IGNITER
I16
I17
I18
I19
I20
I21
1E 51G 8

72
STARTING AND IGNITION (5S±FE)
4
107
9 AM2 AM1ACC
IG1
ST1
IG2
ST2
30A
AM210A
STARTER 40A
MAIN
A 1
B 12C 52F12C2 1
1 2H 22G 1
B1A 1
IG EF1 1EF1 1
M 52 31
2 1
E20 EF1 3B±O
B±W
B±O
B±R
BB±W
W±RW
B±WB W
B±W B±W
B W±BB±R
B
B
B±W B±W
B± R(
M/T)
(
M/T)
(
A/T)
(
A/T)
(
M/T)
(
A/T) W±B
4 5
P
N
65
W
B B
W±BB±R
W±B
B±R
PARK/NEUTRAL POSITION SW
(
NE UTRA L START SW)
(
A/T) P1CLUTCH START
SW(
M/T) C7
STARTER
RELAY IGNITION SW I12
FL MAIN
2. 0L
BATTERY
TO CIRCUIT OPENING
RELAY TO ENGINE CONTROL
MODULE(
ENGINE AND
ELE CTRONIC CO NTROLLED
TRANSMISSION
ECU(
A/T)
,
ENGINE ECU(
M/T))
B S3 ,S4A
B F10 , F16A
STARTER
FUSE BOX100A ALT
IP 1 17
1G 6
1E 5
140A
AM1
1E 11G 9
2
3B 20 3D23C 2
3C 18
1M 13C 6
1C 11

73
*
2 : EX. CALIFORNIA * 1 : CALIFORNIA
* 3 : ONE BODY ASSEMBLY EX. CALIFORNIA
A 1A2A4A3
B 1B4B3
B 4B5B18 B13 B3B22 A 4A18 A17 A3A20
ECIP1 16
E20
E1 9
IP1 8
W±R W±R W±R
B±R
W±R B B
BW W±R L L B
Y R BR
W±R W±R
B
DATA LINK
CONNECTOR 1
(
CHECK CONNECTOR) D1 IGNITER I2 IGNITION COIL I3 TO NOISE FILER
(
FOR IGNITION SYSTEM)
TO TACHOMETER
[COMB. METER] B±O
NE+ G+ G± NE± IGF IGT IG±+B C±
IG± NE G1 G± G2 NE± IGF IGT12 4 53
19 B 2 (
*1)
(
*
2)
(
*2, M/T) (
*1, A/T)
A 5
L
(
*1, A/T)
(
*
2, M/T)
(
SHIELDED)
B E7 ,E11AB D2 ,D2A
ENGINE CONTROL MODULE(
ENGINE AND
ELECTRONIC CONTROLLED TRANSMISSION
ECU)DISTRIBUTOR(
*1)(
*2)
E16W±R
NE G1 G± G2
(
*
2) (
*
1) (
*3)1
2
1A 61G 8

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.

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

82
ENGINE CONTROL (1MZ±FE)
A A
I18 I18 I18
ED 1 2
4 53 1
1 432 7VG±
B 21THA
B 22E2
B 7VTA
A 32IDL
C 14THG
B 20THW
D 20A/C
A 34E02
A 28E03 B±O
B±OL±B
BR
G±R
BR BR
BRR±B
L±B
B±Y
L±W
B±Y
W±B
W±BG±B BR G±Y BR1B 15KNKR
EE1 3EE11
WWBR
ENGINE COOLANT TEMP. SENSOR
(
EFI WATER TEMP. SENSOR) E4 EGR GAS
TE MP. SE NSOR
THROTTLE
POSITION
SENSOR T1
MASS AIR FLOW
(
AIR FLOW METER) M6
FROM
A/C AMPLIFIER
KNOCK SENSOR 1 K1
D 5ACT
LG±R
TO
A/C AMPLIFIER E1
1 2D
ENGINE CONTROL MODULE(
ENGINE A ND E LE CTRONIC
CONTROLLED TRANSMISSION ECU) E7 ,E8 ,E9 , E10BC
(
SHIELDED) (
SHIELDED)
I18
L±W
W±BBR
BR
D 26
OXSD 25
HTS IQ1 4IQ15
II1 9 II110 II18
B±O
BR P±BB
P±B B
4 2
31+B E
OX HT
H9
HEATED OXYGEN SENSOR
(
BANK1 SENSOR2)
L±B
I18
B±O
BR (
SHIELDED)
(
SHIELDED)
(
SHIELDED)
+B VG± THA
E2 B 18FC
B 1VC
2
VGB 8VG
BR
B±O
L±RR G±R
L
FROM COOLING
FA N ECU
A 33E01
W±B
B±OR±L R±L 4 2
31+B E
OX HT
H12
HEATED OXYGEN SENSOR
(
BANK2 SENSOR1)
4 2
31+B E
OX HT
H11
HEATED OXYGEN SENSOR
(
BANK1 SENSOR1)
I18 I18
C 10 B 19 B 13 C11B±OB
I18 I18
A 7 B 7 B 6 B 5 B 4 B 3 B 2 B 1B8 E14 E14 E13
E13 E13 E12
A 29 A 30 A 26 A 15 A 16 A 24 A 12A 1 A 2 A 3 A 4 A 5 A 6 A 8 2 1
2 1
2 1
2 1
2 1
2 1
IGNITION
COIL NO. 1 I16
IGNITION
COIL NO. 2 I17
IGNITION
COIL NO. 3 I18
IGNITION
COIL NO. 4 I19
IGNITION
COIL NO. 5 I20
IGNITION
COIL NO. 6 I21
+B COIL1 COIL2 COIL3 COIL4
COIL5COIL6
TA CHGND
IGF IGT1 IGT2 IGT3 IGT4 IGT5 IGT6 IGF IGT1 IGT2 IGT3 IGT4 IGT5 IGT6
C IGNITER I2 , I15B
W±R
W±G
Y±R
GR±B
L±B
R±B
G±RL±B
GR
WB±O B±O
B±O
B±O
B±O
B
W±B G
LG±B
PB±O
B±O
B±O B±O B±O B±O B±O B±O
(
SHIELDED) (
SHIELDED)
(
SHIELDED) W W
L±B
R±LL±B
R±L
V±R
W±B
B±OBR B±OBR B±O
B±O B±O
R±L
OXR HTR OXL HTLW±BB±O