1994 TOYOTA CAMRY Wiring Diagrams Workshop Manual

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

91
*
2 : EX. CALIFORNIA
* 4 : FOR CANADA IN TMM MADE * 1 : CALIFORNIA
* 5 : EX. * 4
B C
I18B 11 B 1B12
R
B
L R
VC VTA IDL
THROTTLE POSITION
SENSOR T11 2
1 2
1 2 E20
E20
E18 E17 E17 1234
2 3
32 112
A 13 A2C 18 C 17 C 5 C 4
B 2 A
4B3B10 B16 B9 PIM THW THA THG E21 E2 NE NE±(
*2)
G± G+B B± O W±R W±R
B±O
B± O
BR BR BR
B±Y
BR BR
BR
BR
BR
BRGR L±BLGB±R G G
W± R W±R
R
L
B
Y
B±O
D6
I3
D2
E7 ,E8 , E10 +B1 ELSW± R
NE+ NE± G± G+(
*2)
VC E2PIM
(
*2)
M1
E4
I10
E1
MANIFOLD ABSOLUTE
PRESSURE SENSOR
(
VACUUM SENSOR)
ENGINE COOLANT TEMP. SENSOR
(
EFI WATER TEMP. SENSOR)
INTAKE AIR TEMP. SENSOR
(
IN±AIR TEMP. SENSOR)
EGR GAS TEMP.
SENSOR
ENGINE CONTROL MODULE(
ENGINE AND ELECTRONIC CONTROLLED TRANSMISSION ECU)(
A/T)
B
DIODE
(
FOR IDLE±UP)
IGNITION COIL
DISTRIBUTOR FROM
I18 E18
4321BR
BR I18
L
L FROM CRUISE
CONTROL ECU 1
P
E19
C 3C20 534
12
W± R
WBW±R
B
W±R
(
SHIELDED)
IGF IGT COIL± +B IG±
IGF IGTIGNITER I2
TO TACHOMETER
[COMB. METER]
C 8
FPU 1 2 B±O
(
*1)
B±O
(
*1) B±RV3
VSV
(
FOR PRESSURE UP)
1342G2(
*1)
(
*1)
(
*2)
NE G2 G± G1(
*1)
B E11 , E12CA,E14ENGINE CONTROL MODULE(
ENGINE ECU)(
M/T) ONE BODY ASSEMBLY
EX. CALIFORNIA
R
BRB±R
1D 1415A
TAIL
1A 1010A
MIR±HTR
3C 53D 5
POWER SOURCESYSTEM(
SEE PAGE 64)

92
ENGINE CONTROL (5S±FE A/T AND CALIFORNIA M/T)
CB
A
321
C
1 78
C
A 6
B 3
A 21 A10 C13 C26 B13A 5
EDI13G±R R±L R±L
G±R
G±R
Y±G G±WBR LG±B
B±Y
W W±B W±B
W±R
B±O
B±O
B
G±R B±O B±O W±R
R±W G±WY±G G±R
E1 TE2 TE1
WW
DATA LINK CONNECTOR 2
(
TDCL) FROM CE SYSTEM
(
SEE P
JUNCTION
CONNECTOR
MALFUNCTION INDICATOR
LAMP(
CHECK E NG INE
WARNING LIGHT)
[COMB. METER]
ACT ACA E01 E02 KNKENGINE CONTROL MODULE(
ENGINE AND ELECTRONIC CONTROLLED TRANSMISSION ECU)(
A/T)
ACT ACA
KNOCK
SENSOR A/C AMPLIFIER A1 0K1 E7 ,E8 ,E10
A
C9 , C10
J1D3
B
(
SHIELDED)
(
SHIELDED)
E16
O2
OXYGEN SENSOR
(
SUB)
1E15BR
BR
5TT
BR±B IP3 11 IP314
A 9 23
4 1
512IP3 2
SPEED
LGP G±B
G V±Y V±Y
R±L
R±L
SP1COMBINATION
METER C8
VEHICLE
SPEED SENSOR
(
SPEED SENSOR) V5
B
BR I13
G±R
G±R(
*5)
(
*4)
R±L
BR BR
1 2BR 7
R±W
ENG
BR
R±L
I18
R±L TO PARK/NEUTRAL POSITION
SW(
NEUTRAL START SW)
TO GENERATOR(
ALTERNATOR)
R±L
G±R(
*5)(
*4)
(
*3)
B E11 , E12CA,E14
ENGINE CONTROL MODULE(
ENGINE ECU)(
M/T) G±R
(
*
4)
1B 6 10A
GAUGE
1D6
3D 73D19
3D 18
3D 22
3D 10
3D 3
3D 12
POWER SOUR
AGE 64)

93
* 1 : CALIFORNIA
*
2 : EX. CALIFORNIA
* 3 : EX. CALIFORNIA M/T
*
5 : EX.*
4 *
4 : FOR CANADA IN TMM MADE
CB
17 8 9 13 4 15
146 212 1
23 IP119
IP115
IP313
IP11
IP3196 61
666
M
5 4
E17I18 I18 I18
I18
I18I18 I18 I18 I18
IP3 15IP1 4
BX1 4IJ 1 16
BX1 5
BL IG 2 1
EC B 7B15 B14 B8A11
A
14 B5B6A143
BR±B
GR
G±W
R±W B±O
B±W B±WB±O L±B
G±R
W±B W±B W±BW±B W±B L±B L±BBRR±W G±WGR BR±B
L±BBR R±LW
B±O W
R±L
BRR±LBR BR BR BR
W
G±R
L±B
W±R
B±O
B±O
G±R
BR±B
Y±G
G±W
R±W
(
SHIELDED)G±RL±B
R±LW
BR BR±B
GR
G±W
R±WTT TE1 TE2 VF1 OX1 OX2 E1
B±O B±W
B±W
(
SHIELDED) BR (
SHIELDED) (
SHIELDED) (
SHIELDED)
W±R
D1
E1 OX2 OX1 FCTT TE1 TE2 VF STAW+B FP
E7 ,E8 ,E10
N1
F15
O3FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
10A
STARTER
DATA LINK CONNECTOR 1
(
CHE CK CONNE CTOR)
CIRCUIT
OPENING
RELAY
NOISE FILTER
(
FOR IGNITION SYSTEM)
OXYGEN SENSOR(
MAIN)FUEL
PUMP ENGINE CONTROL MODULE(
ENGINE AND ELECTRONIC
CONTROLLED TRANSMISSION ECU)(
A/T)
C
E16 BR1 B
BR BRBR 19
IG±
BR BR
IP316
BR
BR
ED4
I18
BR(
SHIELDED) (
*3)(
*3)
(
*3) (
*3)
B E11 , E12CA,E14
ENGINE CONTROL MODULE(
ENGINE ECU)(
M/T)
3D 2
3C 2
3B20
3A 13
1C 113C 18
1M 1

94
ENGINE CONTROL (5S±FE A/T AND CALIFORNIA M/T)
E 7(C), E 8(B), E10(A) ENGINE CONTROL MODULE (ENGINE AND ELECTRONIC CONTROLLED TRANSMISSION ECU) (A/T)E11(C), E12(B), E14(A) ENGINE CONTROL MODULE (ENGINE ECU) (M/T)
VOLTAGE AT ENGINE CONTROL MODULE (ECU) WIRING CONNECTOR
BATT ± E1: ALWAYS 9.0±14.0 VOLTS
+B ± E1:9.0±14.0 VOLTS (IGNITION SW AT ON POSITION)
+B1 ± E1:9.0±14.0 VOLTS (IGNITION SW AT ON POSITION)
IDL ± E2:9.0±14.0 VOLTS (IGNITION SW ON AND THROTTLE VALVE OPEN)
VC ± E2:4.5± 5.5 VOLTS (IGNITION SW AT ON POSITION)
VTA ± E2:0.3± 0.8 VOLTS (IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED)
:3.2± 4.9 VOLTS (IGNITION SW ON AND THROTTLE VALVE OPEN)
PIM ± E2:3.3± 3.9 VOLTS (IGNITION SW AT ON POSITION)
#10, #20 ± E01, E02:9.0±14.0 VOLTS (IGNITION SW AT ON POSITION) (EX. CALIFORNIA)
#10, #20,
#30, #40 ± E01, E02:9.0±14.0 VOLTS (IGNITION SW AT ON POSITION) (CALIFORNIA)
THA ± E2:0.5± 3.4 VOLTS (IGNITION SW ON AND INTAKE AIR TEMP. 20°C, 68°F)
THW ± E2:0.2± 1.0 VOLTS (IGNITION SW ON AND COOLANT TEMP. 80°C, 176°F)
STA ± E1:6.0±14.0 VOLTS (ENGINE CRANKING)
IGT ± E1: PULSE GENERATION (ENGINE CRANKING OR IDLING)
W ± E1:9.0±14.0 VOLTS (NO TROUBLE AND ENGINE RUNNING)
ACT ± E1:9.0±14.0 VOLTS (IGNITION SW ON AND AIR CONDITIONING ON)
ACA ± E1:7.5±14.0 VOLTS (IGNITION SW ON AND AIR CONDITIONING ON)
TE1 ± E1:9.0±14.0 VOLTS (IGNITION SW ON)
NSW ± E1:0± 3.0 VOLTS (IGNITION SW ON AND PARK/NEUTRAL POSITION SW (NEUTRAL START SW)
POSITION P OR N POSITION)
9.0±14.0 VOLTS (IGNITION SW ON AND EX. PARK/NEUTRAL POSITION SW
(NEUTRAL START SW) POSITION P OR N POSITION)
RESISTANCE AT ENGINE CONTROL MODULE (ECU) WIRING CONNECTORS
(DISCONNECT WIRING CONNECTOR)
IDL ± E2: INFINITY (THROTTLE VALVE OPEN)
2.3 KW OR LESS (THROTTLE VALVE FULLY CLOSED)
VTA ± E2:3.3 ±10.0 KW (THROTTLE VALVE FULLY OPEN)
0.2 ± 0.8 KW (THROTTLE VALVE FULLY CLOSED)
VC ± E2:3.0 ±7 0 KW
THA ± E2:2.0 ±3.0 KW (INTAKE AIR TEMP. 20°C, 68°F)
THW ± E2:0.2 ±0.4 KW (COOLANT TEMP. 80°C, 176°F)
G1, NE ± G±:0.17±0.21 KW
ISCC, ISCO± +B, +B1:19.3±22.3 W
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A1032E11A32J 133
C 832E12C32K 131
C 9A32E14B32M 131
C10C32F15A34 (S/D), 35 (C/P), 36 (W/G)N 131
D 130I 131O 231
D 230I 231O 331
D 332I 331T 131
D 632I 431V 131
E 130I 531V 231
E 430I 631V 331
E 7C32I 731V 531
E 8B32I1031
E10A32I1233
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
125R/B NO. 1 (LEFT KICK PANEL)
626R/B NO. 6 (BEHIND GLOVE BOX)
SERVICE HINTS

95
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1A
1B
1C20COWL WIRE AND J/B NO 1 (INSTRUMENT PANEL LEFT)1D20COWL WIRE AND J/B NO. 1 (INSTRUMENT PANEL LEFT)
1G
1M
2D22ENGINE WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
3A
3B24COWL WIRE AND J/B NO 3 (BEHIND COMBINATION METER)3C24COWL WIRE AND J/B NO. 3 (BEHIND COMBINATION METER)
3D
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IJ142FLOOR NO. 1 WIRE AND COWL WIRE
IP144ENGINE WIRE AND COWL WIREIP344ENGINE WIRE AND COWL WIRE
46 (S/D)
BX148 (C/P)FUEL GAUGE WIRE AND FLOOR NO. 1 WIREBX1
50 (W/G)
FUEL GAUGE WIRE AND FLOOR NO. 1 WIRE
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EB40 (5S±FE)FRONT LEFT FENDER
EC40 (5S±FE)INTAKE MANIFOLD RH
ED40 (5S±FE)INTAKE MANIFOLD LH
IG42INSTRUMENT PANEL BRACE LH
46 (S/D)
BL48 (C/P)UNDER THE LEFT QUARTER PILLARBL
50 (W/G)
UNDER THE LEFT QUARTER PILLAR
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E15I 244COWL WIREE16I1344COWL WIRE
E1740 (5S FE)ENGINE WIREI1844ENGINE WIRE
E1840 (5S±FE)ENGINE WIREI2044COWL WIREE19I2344COWL WIRE
E20

96
ENGINE CONTROL (5S±FE A/T AND CALIFORNIA M/T)*
1 : CALIFORNIA
2 : EX. CALIFORNIA