1994 TOYOTA CAMRY main relay

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

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

98
ENGINE CONTROL (5S±FE M/T EX. CALIFORNIA)
B4 A
IG2
ACC
IG1 ST2AM2
AM1
ST1
9
1 2
1 2
1 2
1 2 E20
E20
E20I20
I18I23 E20 E17E17
I18
I18
EBC 2C 7
A 25 A12C A 1 A 9A10
B 10 B 11 B12 IP3 12
2 1 2D 2
2B 22C3
31 2 2C A4
W±B
WY
R
B
L RW±R
W±R
W±R
W±RW±R W±R W±R W±R B±O
W±G
B±O B±O
B±O B±OG±Y G±R
LG W±L W±B
BRRB±O B±O B±O W±R
B±O B±O B±O B±O
B±O
# 20 # 10 VC VTA IDLBATT ISCVISCC ISCO +B 15A
EFI
EFI MAIN
RELAY
VSV
(
FOR A/C IDLE±UP) IDLE AIR CONTROL
VALVE
(
ISC VALVE)
ENGINE CONTROL MODULE(
ENGINE ECU)
THROTTLE POSITION
SENSOR
INJECTOR NO. 1
INJECTOR NO. 3
INJECTOR NO. 2
INJECTOR NO. 4 I4
I6
I5
I7
T1 E11 , E12 , E1
V1I1
W±R
IGNITION SW I12
IP1 11
B±O
231 2
B±O G
EGR
VSV
(
FOR EGR)
A FROM POWER SOURCE SYST
25 13
4321
V2IP1 9
W±R
I18
L
L FROM CRUISE
CONTROL ECU
B±O
IP1 18
B±O
B±O
WE18 E18
Y Y W
W
7. 5A
IGN
1D 9
1A 61G 8
EM(
SEEPAGE64)

101
* 2 : TMM MADE *
1:TMCMADE
AB
8913 415
146 212 1
23 IP313
IP11
IP3196 62C A6
666
M
5 4 I18
I18I18 I18 I18
IP3 15IP1 4
BX1 4IJ1 16IP3 18
BX1 5
BL IG 2 1
ECB 15 B7B8A2
C
B 1B6C43
GR
G±W
R±W B±O
B±W 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
L±BBR R±LW
B±O W BRR±L
W
G±R
L±B
W±R
B±O
B±O
G±R
Y±G
G±W
R±W
(
SHIELDED)G±RL±B
R±LW
BR
BR GR
G±W
R±WTE1 TE2 VF1 OX1 OX2 E1
B±O B±W
W±RD1
OX2 OX1 FCTE1 TE2 VF STAWB FP
E11 , E12 , E14
N1
F15
O3
O2FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
10A
STARTER
DATA LINK CONNECTOR 1
(
CHECK CONNECTOR)
CIRCUIT
OPENING
RELAY
NOISE FILTER
(
FOR I GNITI ON
SYSTEM)
OXYGEN SENSOR
(
SUB)OXYGEN SENSOR
(
MAIN)FUEL
PUMP ENGINE CONTROL MODULE(
ENGINE ECU) IG± 19 B
BR(
SHIELDED) IP119
ED 2 11 IP316
BR BR(
SHIELDED)
(
SHIELDED)
R±L
BR BR
BR
BR
B±W
(
*2)(
*1)
B±W
E17
3C 2
3D 23B
3A 13
3C 18
1C 11
1M 1

102
ENGINE CONTROL (5S±FE M/T EX. CALIFORNIA)
E11(A), E12(B), E14(C) ENGINE CONTROL MODULE (ENGINE ECU)
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 ± E1:9.0±14.0 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)
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 ± E1:0.8±1.2 VOLTS (ENGINE CRANKING OR IDLING)
ISCC, ISCO± E1:8.0±14.0 VOLTS (IGNITION SW AT ON POSITION)
W ± E1:9.0±14.0 VOLTS (IGNITION SW ON, 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)
RESISTANCE AT ENGINE CONTROL MODULE (ECU) WIRING CONNECTORS
(DISCONNECT WIRING CONNECTOR)
IDL ± E1: INFINITY (THROTTLE VALVE OPEN)
0 W (THROTTLE VALVE FULLY CLOSED)
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)
G+ ± G±:0.17±0.21 KW
ISCC, ISCO± +B, +B1:19.3±22.3 KW
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A1032E14C30K 131
C 832F1534 (S/D), 35 (C/P), 36 (W/G)M 131
C 9A32I 131N 131
C10B32I 231O 231
D 130I 331O 331
D 230I 431T 131
D 332I 531V 131
D 632I 631V 231
E 130I 731V 331
E 430I1031V 531
E11A30I1233
E12B30J 133
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
626R/B NO. 6 (BEHIND GLOVE BOX)
: 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
2A22ENGINE ROOM MAIN WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
2C22ENGINE WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
3A
3C24COWL WIRE AND J/B NO. 3 (BEHIND COMBINATION METER)
3D
24COWL WIRE AND J/B NO. 3 (BEHIND COMBINATION METER)
SERVICE HINTS

104
HEADLIGHT (FOR USA)
3
4
13 14 12
11 9 OFF
TAIL
HEAD
LOW
HIGH
FLASH
LIGHT
CO NTRO L
SW DIMMER SW
COMBINATION SW
R±B
I5E4
IE I52 1
2 1
2 1
2 1
14 13
E4E3
EB I2 ED18 W
R±B
R±Y R±Y
R±Y
R
R W±BR±B R±B
W±B R±B
R±B
W±B W±B
W±B W±BR±B
R±B R±YB
R±B ED1 5R±Y
R±Y INTEGRATION RELAYBATTERY
FL M AI N
2. 0L
HIGH BEAM INDICATOR
LIGHT [COMB. METER]
HEADLIGHT HI RH
HEADLIGHT LO RH
HEADLIGHT HI LH
HEADLIGHT LO LH
C12
I13
C9
H2
H4
H1
H3
2G 72E1HE ADLIGHT
RE LAY
31 42
40A
MAIN
2H 2
15A
HE AD
(
RH)15A
HEAD
(
LH)
2A 2A 15 2E 2
2A 22A6

105
HEADLIGHT RELAY
2±1 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION OR DIMMER SW AT FLASH POSITION
LIGHT AUTO TURN OFF OPERATION
PLEASE REFER TO THE LIGHT AUTO TURN OFF SYSTEM (SEE PAGE 102)
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C 932H 228 (1MZ±FE), 30 (5S±FE)I1333
C1232H 328 (1MZ±FE), 30 (5S±FE)
H 128 (1MZ±FE), 30 (5S±FE)H 428 (1MZ±FE), 30 (5S±FE)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
2A22ENGINE ROOM MAIN WIRE AND J/B NO 2 (ENGINE COMPARTMENT LEFT)2E22ENGINE ROOM MAIN WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
2G22COWL WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
2H22ENGINE WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
ED138 (1MZ±FE)COWL WIRE AND ENGINE ROOM MAIN WIREED140 (5S±FE)COWL WIRE AND ENGINE ROOM MAIN WIRE
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EB38 (1MZ±FE)FRONT LEFT FENDEREB40 (5S±FE)FRONT LEFT FENDER
IE42LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E338 (1MZ±FE)E 440 (5S±FE)ENGINE ROOM MAIN WIREE 340 (5S±FE)ENGINE ROOM MAIN WIREI 244COWL WIREE 438 (1MZ±FE)
ENGINE ROOM MAIN WIRE
I 544COWL WIRE
X X131412
12
34 C9 C12 H1,H2
H3,H4 I13BLACK BLACK
BROWNXXX
X9
1112 13 14
SERVICE HINTS