1994 TOYOTA CAMRY sensor

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.

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

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)

99
AB
1 2
1 2
1 2 E20
E20
E18 E17 E171234
32 112
C 1A 5 A 18 A 17 A 4
B 2C
4B3B13 B9 B 16 IP116
PIM THW THA THG E2E21 NE NE± G± G+
(
SHIELDED) B B±O W±R W± R
B±O
B±O
R
BRBR BR BR BR
B±Y
BR
BR
BR
BR
BRGR L±BLGW±R W±R
R
L
B
Y
B±O
D6
I3
D2
E11 , E12 , E14 +B1W±R
NE+ NE± G± G+
VC E2PIM
M1
E4
I10
E1
MANIFOLD ABSOLUTE
PRESSURE SENSOR
(
VACUUM SENSOR)
ENGINE COOLANT
TEMP. SENSOR
(
EFI WATER TEMP.
SENSOR)
INTAKE AIR
TEM P. SE NSOR
(
IN±AIR TEMP.
SENSOR)
EGR GAS TEMP.
SENSOR
ENGINE CONTROL MODULE(
ENGINE ECU)
B
DIODE
(
FOR IDLE±UP)
IGNITION COIL
DISTRIBUTOR
I18 E18
BR
BRBR 2 3
C 12
B±R G G
ELS FRO E 64)
1
P
E19
A 3A22
W±R
WB±R
W±R
BB
B
W± R
B± R
12 534
COIL± +B
IG F IGT
IG F IGTIGNITER I2
TO
TACHOMETER
[COMB. METER]
W±R
(
*
2)B±O
B±O
NE+
1D 1415A
TAIL
1A 1010A
MIR±HTR
3C 53D 5
M POWER SOURCE SYSTEM(
SEE PAG

100
ENGINE CONTROL (5S±FE M/T EX. CALIFORNIA)
AB A
321
C
1 78
C
A 6
B 3
C 6A13 A 26 B5C 8
1
ED
G±R G±R R±L R±L
G±R
G±WBR LG±B
B±Y
W W±B
W±B
W±R
B±O
B±O
G±RB±O B±O W±R
R±W G±WY±G E1 TE2 TE1
WW
DATA LINK CONNECTOR 2
(
TDCL) FROM POWER SOURCE SYST GE 64)
COMBINATION
METER
ACT ACA E01E02 KNKENGINE CONTROL MODULE(
ENGINE ECU)
ACT ACA
KNOCK
SENSOR A/C AMPLIFIER A1 0
K1 E11 , E12 , E14C C8D3
(
SHIELDED)
I18 I18 24
BR BR
(
SHIELDED) (
SHIELDED) (
SHIELDED) E1
AB
IP3 11 IP314
C 11IP3 2
4 231
512
P
LG
R±L
R±L G±B
G V±Y V±Y
MALFUNCTION
INDICATOR LAMP
(
CHECK ENGINE
WARNING LIGHT)
[COMB. METER] C9 ,C10B SPEED
METER V5
VEHICLE
SPEED SENSOR
(
SPEED SENSOR)
JUNCTION
CONNECTOR J1
SPD
BR
G±R
7
R±W
ENG
I18
BR BR E15
BR BRBR (
SHIELDED)G±R
BR I18
R±L
R±L
R±LTO BACK±UP LIGHT SW
TO GE NE RA TOR(
ALTERNATOR) B
I13I13 G±R
(
*2)
G±R
(
*1)
C 3
3D 3
3D 12
3D 22
3D 10
3D 18 3D73D19
1B 6 10A
GAUGE
1D6
EM(
SEE PA