1994 TOYOTA CAMRY ECU

212
ABS (ANTI±LOCK BRAKE SYSTEM) (TMC MADE)
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL AND REAR WHEELS WHEN THE BRAKES ARE APPLIED IN A PANIC STOP SO THAT THE
WHEELS DO NOT LOCK. THIS RESULTS IN IMPROVED DIRECTIONAL STABILITY AND STEERABILITY DURING PANIC BRAKEING.
1. INPUT SIGNALS
(1) SPEED SENSOR SIGNAL
THE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS ECU.
(2) STOP LIGHT SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN BRAKE PEDAL IS OPERATED.
(3) PARKING BRAKE SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL PKB OF THE ABS ECU WHEN THE PARKING BRAKE IS OPERATED.
2. SYSTEM OPERATION
DURING SUDDEN BRAKEING THE ABS ECU, WHICH HAS SIGNALS INPUT FROM EACH SENSOR, CONTROLS THE CURRENT
FLOWING TO THE SOLENOID INSIDE THE ACTUATOR AND LETS THE HYDRAULIC PRESSURE ACTING ON EACH WHEEL CYLINDER
ESCAPE TO THE RESERVOIR. THE PUMP INSIDE THE ACTUATOR IS ALSO OPERATING AT THIS TIME AND IT RETURNS THE BRAKE
FLUID FROM THE RESERVOIR TO THE MASTER CYLINDER, THUS PREVENTING LOCKING OF THE VEHICLE WHEELS.
IF THE ECU JUDGES THAT THE HYDRAULIC PRESSURE ACTING ON THE WHEEL CYLINDER IS INSUFFICIENT, THE CURRENT
ACTING ON THE SOLENOID IS CONTROLLED AND THE HYDRAULIC PRESSURE IS INCREASED. HOLDING OF THE HYDRAULIC
PRESSURE IS ALSO CONTROLLED BY THE ECU, BY THE SAME METHOD AS ABOVE. BY REPEATED PRESSURE REDUCTION,
HOLDING AND INCREASE ARE REPLATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE STEERBILITY DURING SUDDEN
BRAKING.
A 4(A), A 5(B) ABS ACTUATOR
(A)1, (A)3, (A)4, (A)6 ± (A)2 : APPROX. 6 W
(A)2±GROUND : APPROX. 5 W
A 6(B), A 7(A) ABS RELAY
(A)1±(B) 3 : 60 W±100 W
(A)4±(B) 3 : 60 W±100 W
(A)1, (B) 2±GROUND : APPROX. 12 VOLTS
(A)6±GROUND : APPROX. 12 VOLTS
A 8, A 9 ABS SPEED SENSOR FRONT LH, RH
1±2 : 0.8 K±1.3 KW
A19, A20 ABS SPEED SENSOR REAR LH, RH
1±2 : 1.1 K±1.5 KW
A13(A), A14(B) ABS ECU
(CONNECT THE ECU CONNECTORS)
(A) 5±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND DATA LINK CONNECTOR 1 (CHECK CONNECTOR)
TS±EI NOT CONNECTED
(B)15±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND DATA LINK CONNECTOR 1 (CHECK CONNECTOR)
TS±EI NOT CONNECTED
(A) 1±GROUND, (A) 13±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND ABS WARNING LIGHT GOES OFF
(A)14±GROUND, (A) 1±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND ABS WARNING LIGHT GOES OFF
(A)26±GROUND, (A) 18±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND ABS WARNING LIGHT GOES OFF
(A) 2±GROUND : ALWAYS CONTINUITY
(A)15±GROUND : ALWAYS CONTINUITY
(A)12±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
(B) 6±GROUND : APPROX. 12 VOLTS WITH BRAKE PEDAL DEPRESSED
(A)25±GROUND : ALWAYS APPROX. 12 VOLTS
SYSTEM OUTLINE
SERVICE HINTS

214
ABS (ANTI±LOCK BRAKE SYSTEM) (TMM MADE)
EC1 7
IR2 7IR26IR2 1 IR1 19
B 1A9B 2
A 11 A5A13 A7
IJ1 6IR2 5
I21 I14
1 21 2 B 2B1 A 2A1
2 1
FR+ FR± FL+ FL± +BS STPIG
W
B
R
GR
G
W±B W± B W±BB±R G±WW±L
G±W
G±R
B±R W± L
G±W
G±W
G± R
B±R
G±W
(
SHIELDED) (
SHIELDED)
(
SHIELDED)B A4 ,A5A
ABS ACTUATOR AND ECU FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
B N2 ,N3A
NOISE FILTER
(
FO R STO P L I G HT)
STOP LIGHT SW S10
W± B
A9 A8
ABS SPEED SENSOR
FRONT RHABS SPEED SENSOR
FRONT LH FUS E BO X F18
60A ABS
11M 31A7 15A
STOP15A
ECU±IG
1A 151M 6
3C 19
3C 7
3C 153C 16

215
C C IP3 8IP13EC13IP33
IR1 20 IR23IR28
IJ 1 19 IJ112 IS14IS16IS15 IR1 13A 12 A15 B3A1
A 4A2A6A14 B4 I13
B 4A 6
2 12 1
EA C C
RL+ RL± RR+ RR± GNDTC TS TC ABS
IR2 2IR112 IR24 11 16 23 22WA WB
I13 G±B G±B
TC TS LP W
R
G
W
B R
G R
G
W
BW
B
W±B W±B
W±BW±B
LG±R
R±G
G±B G±BLG±R
R±G
G±WLG±R
G±B G± B
R±L R±LY±B Y±B
R±G
G±W
G±B LG±R
4 14
A1 9A20 J3D3
J1 DATA LINK
CONNECTOR 2
(
CHE CK
CONNECTOR)
JUNCTION
CONNE CTORJUNCTION
CONNECTOR SHORT PIN
ABS SPEED SENSOR
RE AR RHABS SPEED SENSOR
REAR LH DATA LINK CONNE CTOR 1
(
CHECK CONNECTOR) D1
(
SHIELDED) (
SHIELDED) (
SHIELDED)(
SHIELDED)
(
SHIELDED)
(
SHIELDED)B C9 ,C10
A
B A4 ,A5AABS WARNING
LIGHT
(
COMB. LIGHT)
ABS ACTUATOR AND ECUFROM POWER SOURCE SYSTEM(
SEE PAGE 64)
3C 17 3D 17 3D163C 13 3C12 3C 3
10A
GAUGE
1B 6

218
ABS (ANTI±LOCK BRAKE SYSTEM) (TMM MADE)
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL AND REAR WHEELS WHEN THE BRAKES ARE APPLIED IN A PANIC STOP SO THAT THE
WHEELS DO NOT LOCK. THIS RESULTS IN IMPROVED DIRECTIONAL STABILITY AND STEERABILITY DURING PANIC BRAKEING.
1. INPUT SIGNALS
(1) SPEED SENSOR SIGNAL
THE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS ECU.
(2) STOP LIGHT SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN BRAKE PEDAL IS OPERATED.
2. SYSTEM OPERATION
DURING SUDDEN BRAKEING THE ABS ECU, WHICH HAS SIGNALS INPUT FROM EACH SENSOR, CONTROLS THE CURRENT
FLOWING TO THE SOLENOID INSIDE THE ACTUATOR AND LETS THE HYDRAULIC PRESSURE ACTING ON EACH WHEEL CYLINDER
ESCAPE TO THE RESERVOIR. THE PUMP INSIDE THE ACTUATOR IS ALSO OPERATING AT THIS TIME AND IT RETURNS THE BRAKE
FLUID FROM THE RESERVOIR TO THE MASTER CYLINDER, THUS PREVENTING LOCKING OF THE VEHICLE WHEELS.
IF THE ECU JUDGES THAT THE HYDRAULIC PRESSURE ACTING ON THE WHEEL CYLINDER IS INSUFFICIENT, THE CURRENT
ACTING ON THE SOLENOID IS CONTROLLED AND THE HYDRAULIC PRESSURE IS INCREASED. HOLDING OF THE HYDRAULIC
PRESSURE IS ALSO CONTROLLED BY THE ECU, BY THE SAME METHOD AS ABOVE. BY REPEATED PRESSURE REDUCTION,
HOLDING AND INCREASE ARE REPLATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE STEERBILITY DURING SUDDEN
BRAKING.
A 8, A 9 ABS SPEED SENSOR FRONT LH, RH
1±2 : 0.8 K±1.3 KW
A19, A20 ABS SPEED SENSOR REAR LH, RH
1±2 : 1.1 K±1.5 KW
A 4(A), A 5(B) ABS ECU
(CONNECT THE ECU CONNECTORS)
(A)12±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND DATA LINK CONNECTOR 1 (CHECK CONNECTOR)
TS±EI NOT CONNECTED
(A)15±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND DATA LINK CONNECTOR 1 (CHECK CONNECTOR)
TS±EI NOT CONNECTED
(B) 4±GROUND : ALWAYS CONTINUITY
(B) 2±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
(A) 9±GROUND : APPROX. 12 VOLTS WITH BRAKE PEDAL DEPRESSED
(B) 1±GROUND : ALWAYS APPROX. 12 VOLTS
SYSTEM OUTLINE
SERVICE HINTS

220
ELECTRIC TENSION REDUCER
1 2
1 2 1 2
1 2IS 1 3
BLTE NSI ON
RE DUCER
SOLENOID LHTENSION
REDUCER
SOLENOID RH
BUCKLE
SW LHBUCKLE
SW RH FROM POWE
R
GB±RB±R W±B
B7,B8 B10T3 T2B±R
B±R
IJ1 1
B±R
2 1
R±Y
D25
DIODE
(
FOR TENSION REDUCER)
W±B
15A
ECU±IG R SOURCE SYSTEM(
SEE PAGE 64)
1A 7
3A14
3D 53C 16

222
AUTO ANTENNA (S/D, C/P)*
1 : 6 SPEAKER
* 2 : 4 SPEAKER
W±B
AUTO ANTENNA MOTOR
AND CONTROL RELAY
BM A2 1M 145786 256431
R
2G 2
IU1 3 A A
R R R
JUNCTION
CONNECTOR J33
8
1OFF
B±R
L±R
RA DIO AND PLA YER(
*1)
RADIO SW
PLAYER
SW ON
B±R
P±L
II2 9 II2 13
IU1 1IU12
IU1 9IU110IM28
3
8
9OFF RADIO SW
PLAYER
SW ON 9
BB B
L±RB±R
L±R B±R
L±R
GR
W P±L B±R L±R B±R
P±L B±RGRR B±R FROM POWER S OURCE SY STE M(
SEE PAGE 64)
ACC
J UNCTION
CONNECTORSTEREO COMPONENT
AMPLIFIER
RA DIO AND PLA YER(
*2)
(
*2) (
*2)
(
*1) (
*1)
J3S8
R2
R3
L±Y
Y
R±G
B
R±W
W±B
23
LB 20A
DOME
W±B IM2 9 II2 3
R
1L 11L9 15A
ECU±IG15A
CIG/RADIO
1K 121C 1

224
AUTO ANTENNA (W/G)*
1 : 8 SPEAKER
* 2 : 6 SPEAKER
W±B
AUTO ANTENNA MOTOR
AND RELAY
BL A2 1
M 145786 256431
RR R
3
8
1OFF
B±R
L±R
RADIO A ND P LAY ER(
*1)
RADIO S W
PLAYER
SW ON
B±R
P±L
II2 9 II2 13
IG1 1IG12
IG1 9IG110IM28
3
8
9OFF RADIO S W
PLAYER
SW ON 9
BB B
L±RB±R
L±R B±R
L±R
GR
W P±L B±R L±R B±R
P±L B±RGR RB±R ACC
JUNCTION
CONNE CTORSTEREO COMPONENT
AMPLIFIER
RADIO A ND P LAY ER(
*2)
(
*2) (
*2)
(
*1) (
*1)
J3S8
R2
R3
L±Y
Y
R±G
B
R±W
W±B
23
LBW±B IM2 9
C C
JUNCTION
CONNECTOR J5
1H 61C 1
2G 21L11L9 FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
15A
ECU±IG15A
CIG/RA DIO 20A
DOME

236
COMBINATION METER
AB
IJ1 5IJ111 IJ118
BX1 3 BX1 2 BX1 1 IP3 2
IP3 6
IP1 8IP 3 11 IP314
IP3 5
IP3 161
ED1 A 4
A 8A7A6A 5A12 B 11 B7B10 C 8C7C 4
123
23
4
1 I9
I9 C C
6 FROM POWER SOURCE SYSTEM(
SEE PAGE 64)
R±L
R±L R±L R±L
BRY±L Y±R
BR BR BR Y±L Y±R Y±R
Y±L
BR
BR BR
B Y±G
BY±G
B
P
LG GG±B
G±B G±B
R±W
Y±B Y±BV±Y
R±L JUNCTION
CONNECTOR
BR
BR
FROM E NGINE CONTROL MODULE
(
E NGINE A ND E LE CTRONIC CONTROLLED
TRANSMISSION ECU)(
A/T)
FROM E NGINE CONTROL MODULE
(
ENGINE ECU)(
M/T)
FROM CRUISE CONTROL ECU
SPEEDFUEL
FUEL
WATER TEMP.
TA CHO
ABS
SEAT BELT
OIL
FUEL SENDER
WATER TEMP.
SENDER
IGNITER
VEHICLE SPEED
SENSOR
(
SPEED SENSOR)
TO AB S ECU
TO INTEGRATION
RELAY
OIL P RES SURE
SW
J2
B
W2
I2
V5
O1F1 5C
COMBINATION METER C8 ,C9 , C10
TO BACK±UP LIGHT SW(
M/T)
TO PARK/NEUTRAL POSITION SW
(
NEUTRAL START SW)(
A/T)
TO GENERA TOR(
ALTERNATOR) R±L
R±L
I18 6
TA C
COOLING FAN
ECU C14
BR
B
B JUNCTION CONNECTOR J7
(
*6) (
*6)
(
*7)A
A
(
*7)
(
*6)
1B 6 1D 610A
GAUGE
3D 13
3D 12
1D 121D 13
3C 133C 12