1986 TOYOTA SUPRA brake light

145
THIS SYSTEM ELECTRICALLY CONTROLS THE LINE PRESSURE, THROTTLE PRESSURE, LOCK±UP PRESSURE AND ACCUMULATOR PRESSURE ETC.
THROUGH THE SOLENOID VALVE. THE ELECTRONICALLY CONTROLLED TRANSMISSION IS A SYSTEM WHICH PRECISELY CONTROLS GEAR SHIFT
TIMING AND LOCK±UP TIMING IN RESPONSE TO THE VEHICLE'S DRIVING CONDITIONS AND THE ENGINE OPERATING CONDITIONS DETECTED BY
VARIOUS SENSORS, MAKING SMOOTH DRIVING POSSIBLE BY SHIFT SELECTION FOR EACH GEAR WHICH IS THE MOST APPROPRIATE TO THE
DRIVING CONDITIONS AT THAT TIME, AND CONTROLS THE ENGINE TORQUE DURING SHIFTING TO ACHIEVE OPTIMUM SHIFT FEELING.
1. GEAR SHIFT OPERATION
WHEN DRIVING, THE ENGINE WARM UP CONDITION IS INPUT AS A SIGNAL TO TERMINAL (B)44 OF THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP.
SENSOR) AND THE VEHICLE SPEED SIGNAL FROM VEHICLE SPEED SENSOR (SPEED SENSOR) NO.2 IS INPUT TO TERMINAL (B) 23 OF THE
ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). AT THE SAME TIME, THE THROTTLE
VALVE OPENING SIGNAL FROM THE THROTTLE POSITION SENSOR (MAIN) IS INPUT TO TERMINAL (B)43 OF THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS THROTTLE ANGLE SIGNAL.
BASED ON THESE SIGNALS, THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU)
SELECTS THE BEST SHIFT POSITION FOR DRIVING CONDITIONS AND SENDS CURRENT TO THE ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOIDS.
WHEN SHIFTING TO 1ST SPEED, THE CURRENT FLOWS FROM TERMINAL (B)10 OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " TERMINAL 4 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "
GROUND AND CONTINUITY TO NO. 1 SOLENOID CAUSES THE SHIFT (NO. 2 SOLENOID DOES NOT HAVE CONTINUITY AT THIS TIME).
FOR 2ND SPEED, THE CURRENT FLOWS SIMULTANEOUSLY FROM TERMINAL (B)9 OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " TERMINAL 8 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "
GROUND, AND FROM TERMINAL (B)10 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION
ECU) " TERMINAL 4 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID " GROUND, AND CONTINUITY TO NO. 1 AND NO. 2
SOLENOIDS CAUSES THE SHIFT.
FOR 3RD SPEED, THERE IS NO CONTINUITY TO NO. 1 SOLENOID, ONLY TO NO. 2 SOLENOID, CAUSING THE SHIFT.
SHIFTING INTO THE 4TH SPEED (OVERDRIVE) OCCURS WHEN NO CURRENT FLOWS TO NO. 1 AND NO. 2 SOLENOIDS. THE NO. 4 SOLENOID (FOR
ACCUMULATOR BACK PRESSURE MODULATION) IS INSTALLED TO ADJUST THE BACK PRESSURE ON THE ACCUMULATOR AND CONTROLS THE
HYDRAULIC PRESSURE DURING SHIFTING AND LOCK±UP IN ORDER TO PROVIDE SMOOTH SHIFTING WITH LITTLE SHIFT SHOCK.
2. LOCK±UP OPERATION
WHEN THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) DECIDES, BASED ON EACH
SIGNAL, THAT THE LOCK±UP CONDITION HAS BEEN MET, THE CURRENT THROUGH EFI NO. 1 FUSE FLOWS FROM THE EFI MAIN RELAY "
TERMINAL 3 OF THE ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID " TERMINAL 7 " TERMINAL (B)14 OF THE ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " GROUND, SO CONTINUITY TO NO. 3 (FOR
LOCK±UP) CAUSES LOCK±UP.
3. STOP LIGHT SW CIRCUIT
IF THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) WHEN DRIVING IN LOCK±UP CONDITION, A SIGNAL IS INPUT TO TERMINAL (A)4
OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OPERATES AND CUTS THE CURRENT TO THE SOLENOID TO RELEASE
LOCK±UP.
4. OVERDRIVE CIRCUIT
*O/D MAIN SW ON
WHEN THE O/D MAIN SW IS TURNED ON (SW POINT IS OPEN), A SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE ELECTRONICALLY CONTROLLED TRANSMISSION
CAUSES SHIFT TO OVERDRIVE WHEN THE CONDITIONS FOR OVERDRIVE ARE MET.
*O/D MAIN SW OFF
WHEN THE O/D MAIN SW IS TURNED OFF (SW POINT IS CLOSED), THE CURRENT FLOWING THROUGH THE O/D OFF INDICATOR LIGHT
FLOWS TO GROUND BY WAY OF THE O/D MAIN SW AND CAUSES THE O/D OFF INDICATOR LIGHT TO LIGHT UP. AT THE SAME TIME, A
SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION
ECU) AND THE ELECTRONICALLY CONTROLLED TRANSMISSION PREVENTS SHIFT INTO OVERDRIVE.
5. ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW CIRCUIT
WHEN THE ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW IS SWICHED FROM NORMAL TO MANUAL, A SIGNAL IS
INPUT TO TERMINAL (A)18 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). INPUT
OF THIS SIGNAL CAUSES CURRENT TO FLOW FROM THE GAUGE FUSE TO TERMINAL (A)1 OF COMBINATION METER " TERMINAL (A)12 "
TERMINAL (A)25 OF ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " GROUND,
LIGHTING UP THE INDICATOR LIGHT. IF THE A/T SHIFT LEVER IS THEN SHIFTED TO ª2º POSITION, THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) ENABLES THE VEHICLE TO START OFF WITH THE TRANSMISSION IS
2ND GEAR, THUS PERMITTING EASING STARTING OFF AND DRIVING ON SLIPPERY ROADS.
6. CRUISE CONTROL
WHEN CRUISE CONTROL OPERATION IS SELECTED A SIGNAL IS INPUT TO TERMINAL (A)12 OF THE ENGINE CONTROL MODULE (ENGINE
AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM CRUISE CONTROL. ECU. AS A RESULT, THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OPERATES AND CONTROLS OVERDRIVE, LOCK±UP AND SO ON FOR
SMOOTH DRIVING.
SYSTEM OUTLINE

155
THIS SYSTEM ELECTRICALLY CONTROLS THE LINE PRESSURE, THROTTLE PRESSURE, LOCK±UP PRESSURE AND ACCUMULATOR PRESSURE ETC.
THROUGH THE SOLENOID VALVE. THE ELECTRONICALLY CONTROLLED TRANSMISSION IS A SYSTEM WHICH PRECISELY CONTROLS GEAR SHIFT
TIMING AND LOCK±UP TIMING IN RESPONSE TO THE VEHICLE'S DRIVING CONDITIONS AND THE ENGINE OPERATING CONDITIONS DETECTED BY
VARIOUS SENSORS, MAKING SMOOTH DRIVING POSSIBLE BY SHIFT SELECTION FOR EACH GEAR WHICH IS THE MOST APPROPRIATE TO THE
DRIVING CONDITIONS AT THAT TIME, AND CONTROLS THE ENGINE TORQUE DURING SHIFTING TO ACHIEVE OPTIMUM SHIFT FEELING.
1. GEAR SHIFT OPERATION
WHEN DRIVING, THE ENGINE WARM UP CONDITION IS INPUT AS A SIGNAL TO TERMINAL (B)44 OF THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP.
SENSOR) AND THE VEHICLE SPEED SIGNAL FROM VEHICLE SPEED SENSOR (SPEED SENSOR) NO.2 IS INPUT TO TERMINAL (B)23 OF THE
ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). AT THE SAME TIME, THE THROTTLE
VALVE OPENING SIGNAL FROM THE THROTTLE POSITION SENSOR IS INPUT TO TERMINAL (B)43 OF THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS THROTTLE ANGLE SIGNAL.
BASED ON THESE SIGNALS, THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU)
SELECTS THE BEST SHIFT POSITION FOR DRIVING CONDITIONS AND SENDS CURRENT TO THE ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOIDS. WHEN SHIFTING TO 1ST SPEED, THE CURRENT FLOWS FROM TERMINAL (B)10 OF THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " TERMINAL 1 OF ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOID " GROUND AND CONTINUITY TO NO. 1 SOLENOID CAUSES THE SHIFT (NO. 2 SOLENOID DOES NOT HAVE
CONTINUITY AT THIS TIME).
FOR 2ND SPEED, THE CURRENT FLOWS SIMULTANEOUSLY FROM TERMINAL (B)9 OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " TERMINAL 2 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "
GROUND, AND FROM TERMINAL (B)10 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION
ECU) " TERMINAL 1 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID " GROUND, AND CONTINUITY TO NO. 1 AND NO. 2
SOLENOIDS CAUSES THE SHIFT.
FOR 3RD SPEED, THERE IS NO CONTINUITY TO NO. 1 SOLENOID, ONLY TO NO. 2 SOLENOID, CAUSING THE SHIFT.
SHIFTING INTO THE 4TH SPEED (OVERDRIVE) OCCURS WHEN NO CURRENT FLOWS TO NO. 1 AND NO. 2 SOLENOIDS.
2. LOCK±UP OPERATION
WHEN THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) JUDGES FROM EACH SIGNAL
THAT LOCK±UP OPERATION CONDITIONS HAVE BEEN MET, CURRENT FLOWS FROM TERMINAL (B)8 OF THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " TERMINAL 3 OF THE ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOID " GROUND, CAUSING CONTINUITY TO THE LOCK±UP SOLENOID AND CAUSING LOCK±UP OPERATION.
3. STOP LIGHT SW CIRCUIT
IF THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) WHEN DRIVING IN LOCK±UP CONDITION, A SIGNAL IS INPUT TO TERMINAL (A)4
OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OPERATES AND CUTS THE CURRENT TO THE SOLENOID TO RELEASE
LOCK±UP.
4. OVERDRIVE CIRCUIT
*O/D MAIN SW ON
WHEN THE O/D MAIN SW IS TURNED ON (SW POINT IS OPEN), A SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE ELECTRONICALLY CONTROLLED TRANSMISSION
CAUSES SHIFT TO OVERDRIVE WHEN THE CONDITIONS FOR OVERDRIVE ARE MET.
*O/D MAIN SW OFF
WHEN THE O/D MAIN SW IS TURNED OFF (SW POINT IS CLOSED), THE CURRENT FLOWING THROUGH THE O/D OFF INDICATOR LIGHT
FLOWS TO GROUND BY WAY OF THE O/D MAIN SW AND CAUSES THE O/D OFF INDICATOR LIGHT TO LIGHT UP. AT THE SAME TIME, A
SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION
ECU) AND THE ELECTRONICALLY CONTROLLED TRANSMISSION PREVENTS SHIFT INTO OVERDRIVE.
5. ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW CIRCUIT
WHEN THE ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW IS SWICHED FROM NORMAL TO MANUAL, A SIGNAL IS
INPUT TO TERMINAL (A)18 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). INPUT
OF THIS SIGNAL CAUSES CURRENT TO FLOW FROM THE GAUGE FUSE TO TERMINAL (A)1 OF COMBINATION METER " TERMINAL (A)12 "
TERMINAL (A)25 OF ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) " GROUND,
LIGHTING UP THE INDICATOR LIGHT. IF THE A/T SHIFT LEVER IS THEN SHIFTED TO ª2º POSITION, THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) ENABLES THE VEHICLE TO START OFF WITH THE TRANSMISSION IN
2ND GEAR, THUS PERMITTING EASING STARTING OFF AND DRIVING ON SLIPPERY ROADS.
6. CRUISE CONTROL
WHEN CRUISE CONTROL OPERATION IS SELECTED A SIGNAL IS INPUT TO TERMINAL (A)12 OF THE ENGINE CONTROL MODULE (ENGINE
AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM CRUISE CONTROL ECU. AS A RESULT, THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OPERATES AND CONTROLS OVERDRIVE, LOCK±UP AND SO ON FOR
SMOOTH DRIVING.
SYSTEM OUTLINE

161
10A
ECU±B10A
ECU±IG15A
STOP10A
GAUGE
1H 81K13 1I10 1E12
I5I14
1 2
I20
I24 2
B 13 A5B4A25 A12 B10 B3B12 B6B14
A 16 A3A10 A9A22 B8B16 B7B9B1A 9
B 1
I4
I22
I22I22 I22
IB 5 1IB52IB56IB54IB55IC29IC23
IB5 3
1 2
1 2
2 1
2 11
IGIF1 15
IC2 8
PARKING BRAKE SWABS SPEED SENSOR
REAR LH ABS SPEED SENSOR
FRONT LH ABS SPEED SENSOR
FRONT RH
ABS SPEED SENSOR
REA R RH
PKB STP GS1 GS2 GST IG1 BAT D/G TC WA
FR+ FR± FSS FL+ FL± RR+ RR± RSS RL+ RL±
BRAKE WARNING LIGHT
[COMB. METER] ABS WARNING LIGHT
[TELLTALE LIGHT LH]STOP LIGHT SW
ABS LATERAL
ACCELERATION
SENSOR DA TA LINK CONNECTOR 2
(
TDCL)
TC ABS GST GS2 GS1 GNDIG1 D5
A2 3
S11
T5 A1 1
A1 0
A3 2
A31
P5P±BL
V±G
W±R
B±R
W±L
R±L
B±O
W
Y Y G±W
LGV (
SHIELDED)
LGV (
SHIELDED) PL (
SHIELDED) B W (
SHIELDED)
B W (
SHIELDED) BR±B BR±B L R
L R
P±B
W±B
BR±WBR±W BR±W YLB±R W±R
BR±W
(
SHIELDED) (
SHIELDED)
L
P±B4
1236 14 4FROM POWER SOURCE SYSTEM(
SEE PAGE 56)
FROM POWER SOURCE SYSTEM(
SEE PAGE 56)
B±R
BR±W BR±W
IF212
B C10 , C12A
ABS ECUA A18 , A19B L
I2
BR±W
BR±W TO BRAKE FLUID
LEVEL WARNING SW

162
ABS (ANTI±LOCK BRAKE SYSTEM)
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL, RIGHT REAR WHEEL AND LEFT REAR WHEEL 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 BRAKING.
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 THE BRAKE PEDAL IS DEPRESSED.
(3) PARKING BRAKE SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL PKB OF THE ABS ECU WHEN THE PARKING BRAKE LEVER IS PULLED UP.
(4) DECELERATION SENSOR SIGNAL
LATERAL ACCELERATION IS DETECTED AND INPUT TO THE ABS ECU.
2. SYSTEM OPERATION
DURING SUDDEN BRAKING, 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 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 REPEATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE
STEERABILITY DURING SUDDEN BRAKING.
A 6(A), A 7(B) ABS ACTUATOR
(A) 1±GROUND : ALWAYS CONTINUOUS
(B) 1, (B) 3, (B) 4, (B) 6±GROUND : APPROX. 1.20
(IGNITION SW OFF)
(B) 2±(A) 4: 4±6
(IGNITION SW OFF)
A10, A11, A31, A32
ABS SPEED SENSOR FRONT LH, RH, REAR LH, RH
1±2: 0.8±1.3 K
(20°C, 68°F)
A18 (B), A19(A)
ABS ECU
(A)12±GROUND : 10±14 VOLTS WITH IGNITION SW ON
(A) 2, (A)15±GROUND: ALWAYS CONTINUOUS
(A)25±GROUND : ALWAYS 10±14 VOLTS
(A)1, (A)13, (A)14,(A)26,±GROUND: 10±14 VOLTS WITH IGNITION SW ON
(B)14±GROUND : CONTINUITY WITH PARKING BRAKE LEVEL PULLED UP
(B) 6±GROUND :10±14 VOLTS WITH STOP LIGHT SW ON (BRAKE PEDAL DEPRESSED)
P 5
PARKING BRAKE SW
1±GROUND: CLOSED WITH PARKING BRAKE LEVER PULLED UP
S11
STOP LIGHT SW
1±2: CLOSED WITH BRAKE PEDAL DEPRESSED
SYSTEM OUTLINE
SERVICE HINTS

169
7. 5A
TRAC10A
ECU±B10A
ECU±IG15A
STOP10A
GAUGE
21H1K1I1E
1 2
IF2 2IF212 IF21IF115I14
I2 IB 3 3FROM POWER SOURCE SYSTEM(
SEE PAGE 56)
A 9
B 7B1
1
I2 LG±R
L±Y
W±R
B±R
G±W
BR±W
L
W
BR±W
B±WSTOP LIGHT
SW
TRAC BRAKE ABS TRA C
OFF TELLTALE
LIGHT LHCOMBINATION
METER
PARKING
BRAKE SWDAYTIME
RUNNING
LIGHT
RELAY
(
MAIN) LG±R
L
W
BR±W
BR±WG±W
Y
BR±W
(
USA)
(
USA)
(
CANADA)(
CANADA) (
USA)
BR±W BR±WW
L
LG±R
BR±W
LG±R
L
W
BR±WY
YL±Y
W±R
B±R
W
Y
842
W
BR±W
B±W (
USA)
(
CANADA) B±W
(
CA NADA)
OIL PKB
188 T5
D6
P58131012
B±W
(
CANADA) S11
B C10 , C12
A
I2:USA
I10 : CANADA1
2

170
ABS AND TRACTION CONTROL
(FOR ABS)
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL, RIGHT REAR WHEEL AND LEFT REAR WHEEL WHEN THE BRAKES ARE APPLIED IN A PANIC
STOP SO THAT THE WHEELS DO NOT LOCK.
THIS RESULTS IN IMPROVED DIRECTIONALLY STABILITY AND STEERABILITY DURING PANIC BRAKING.
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 AND TRACTION
ECU.
(2) STOP LIGHT SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS AND TRACTION ECU WHEN THE BRAKE PEDAL IS DEPRESSED.
(3) PARKING BRAKE SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL PKB OF THE ABS AND TRACTION ECU WHEN THE PARKING BRAKE LEVER IS PULLED UP.
(4) DECELERATION SENSOR SIGNAL
LATERAL ACCELERATION IS DETECTED AND INPUT TO THE ABS AND TRACTION ECU.
2. SYSTEM OPERATION
DURING SUDDEN BRAKING, THE ABS AND TRACTION 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 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 REPEATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE STEERABILITY DURING SUDDEN
BRAKING.
(FOR TRACTION CONTROL)
THE TRACTION CONTROL SYSTEM IS A SYSTEM WHEREBY THE ªABS AND TRACTION ECUº AND ªTRACTION ECUº CONTROLS THE
ENGINE TORQUE AND THE HYDRAULIC PRESSURE OF THE WHEEL CYLINDER OF THE DRIVING WHEELS IN ORDER TO CONTROL
SPINNING OF THE DRIVING WHEELS WHEN STARTING OFF AND ACCELERATING, AND PROVIDE THE MOST APPROPRIATE DRIVING
FORCE IN RESPONSE TO THE ROAD CONDITIONS FOR VEHICLE STABILITY.
TRACTION CONTROL OPERATION
VEHICLE SPEED SIGNALS FROM THE SPEED SENSOR INSTALLED ON EACH WHEEL ARE INPUT TO THE ABS AND TRACTION ECU.
WHEN THE ACCELERATOR PEDAL IS DEPRESSED WHILE DRIVING ON A SLIPPERY ROAD AND THE DRIVING WHEEL (REAR WHEEL)
SLIPS, IF THE ROTATION OF THE REAR WHEEL EXCEEDS THE ROTATION OF THE FRONT WHEELS FOR A SPECIFIED PERIOD, THE
ECU JUDGES THAT THE REAR WHEEL IS SLIPPING.
WHEN THIS OCCURS, CURRENT FLOWS FROM TRACTION ECU TO SUB THROTTLE ACTUATOR TO CLOSE THE SUB THROTTLE
VALVE. AT THE SAME TIME, OPERATION OF THE ABS AND TRACTION ECU CAUSE THE TRACTION BRAKE ACTUATORS (MASTER
CYLINDER CUT, RESERVOIR CUT SOLENOID) TO TURN ON TO SWITCH THE HYDRAULIC CIRCUIT TO ªTRACTIONº MODE.
IN THIS CASE, SIGNALS ARE INPUT FROM TERMINAL SRR OF ABS AND TRACTION ECU TO TERMINAL (B)3 OF ABS ACTUATOR, AND
FROM TERMINAL SRL OF ABS AND TRACTION ECU TO TERMINAL (B)6 OF ABS ACTUATOR, CONTROLLING THE REAR WHEEL
SOLENOID IN THE ABS ACTUATOR AND INCREASING THE HYDRAULIC PRESSURE OF THE WHEEL CYLINDER IN ORDER TO
PREVENT SLIP.
TO MAINTAIN THE HYDRAULIC PRESSURE OF THE REAR WHEELS, THE REAR WHEEL SOLENOID INSIDE THE ABS ACTUATOR IS
PUT IN ªHOLDº MODE AND KEEPS THE HYDRAULIC PRESSURE TO THE WHEEL CYLINDER CONSTANT.
WHEN THE AMOUNT OF SLIP HAS DECREASED, THE HYDRAULIC PRESSURE IN THE WHEEL CYLINDER DECREASES.
SYSTEM OUTLINE

171
A20 (A), A21 (B), A22 (C) ABS AND TRACTION ECU
(A) 7±GROUND : ALWAYS 10±14 VOLTS
(A) 24±GROUND : 10±14 VOLTS WITH IGNITION SW AT ON POSITION
(C) 6±GROUND : 10±14 VOLTS WITH STOP LIGHT SW ON
(A) 25, (C) 4, (C) 9±GROUND : ALWAYS CONTINUOUS
(C) 12±GROUND : 10±14 VOLTS WITH PARKING BRAKE LEVER PULLED UP (PARKING BRAKE SW ON)
A 6 (A), A 7 (B) ABS ACTUATOR
(A) 1±GROUND : ALWAYS CONTINUOUS
(B) 1, (B) 3, (B) 4, (B) 6±GROUND : APPROX. 1.2
(IGNITION SW OFF)
(B) 2±GROUND : 4±6
(IGNITION SW OFF)
T 3 TRACTION BRAKE ACTUATOR
1±3 : APPROX.2.1

2±4 : APPROX.2.1

S11 STOP LIGHT SW
2±1: CLOSED WITH BRAKE PEDAL DEPRESSED
A10, A11, A31, A32 ABS SPEED SENSOR FRONT LH, RH, REAR LH, RH
1±2: 0.8± 1.3 K
(20°C, 68°F)
T 9(A), T10(B) TRACTION ECU
(A)26±GROUND:10±14 VOLTS WITH IGNITION SW AT ON POSTION
(A)13±GROUND: ALWAYS 10±14 VOLTS
(A)14±GROUND: ALWAYS BELOW 1 VOLTS
(A)18±GROUND:10±14 VOLTS WITH IGNITION SW ON PARKING BRAKE LEVER RELEASED (PARKING BRAKE SW OFF)
(A) 3±GROUND:10±14 VOLTS WITH STOP LIGHT SW ON
(A) 5±GROUND:10±14 VOLTS WITH TRAC OFF SW RELEASED
(A)12±GROUND: ALWAYS 10±14 VOLTS
P 5 PARKING BRAKE SW
1±GROUND : CLOSED WITH PARKING BRAKE LEVER DEPRESSED
S 4 SUB THROTTLE ACTUATOR
2±1, 2±3 : APPROX. 1.1

5±4, 5±6 : APPROX. 1.1

: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A 6A24 (2JZ±GTE)B 224 (2JZ±GTE)S 525
A 7B24 (2JZ±GTE)C10A28S1129
A1024 (2JZ±GTE)C12B28T 325
A1124 (2JZ±GTE)D 124 (2JZ±GTE)T 425
A20A28D 528T 529
A21B28D 628T 829
A22C28E 9B29T 9A29
A2328E10A29T10B29
A3130P 529
A3230S 425
SERVICE HINTS

175
15A
STOP
I17
I4I21I 10
IJ2 10 IJ211 IJ13
IB6 10 IB67IB616 IB615 IB69IB617 IB68 A 8
B 2
B 64 A 12 B 9
11 2
3 4 MFROM POWER SOURCE SYSTEM(
SEE PAGE 56)
22 9 21
31 10 16 1236 745
23 24 25 12 11 26
W
B±W
W G±W IDL OD ECT
PKB STP+ L STP±
R±L BR±BG±RLG P±G LG±RR±B R±B
LG±R
P±G
LG
G±R
BR±B
R±L R±LW
W W W G±W G±WB±WW BR±WR BR±BR±L
RRBR±BR±L
R R±L
R±L
VR1 VR2 VR3
MO MC L±MC GND VR1VR2VR3MO CRUISE CONTROL ACTUATOR C4
B±W
TO LIGHT FAILURE
SENSOR
STOP LIGHT SW S11 P5
PARKING BRAKE SW
IDL S2
S2 OD1 IDL1THROTTLE
POSITION SENSOR
ENGINE CONTROL MODULE
(
ENGINE AND ELECTRONICA LLY
CONTROLLED TRA NSMISSION ECU) ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOIDB E2 ,A
A E9 ,E10B
(
2JZ±GE) (
2JZ±GTE)
RES UME/
ACCEL
SET/
COAS T
CANCE L I4
1J 11H 13
IE18 19 13
L R±Y W±B W±B W±B
W±B 1715 5
CCS
ECMS
MAIN
C14
CRUISE CONTROL SW
[COMB. SW]CMS CCSE16 : 2JZ±GTE
I17 : 2J Z±GEA 3
B 2(
2JZ±GTE)
(
2JZ±GE)
(
A/T)
(
A/T) (
A/T) (
A/T)
(
A/T)(
A/T)
L
GND CRUISE CONTROL
ECU C16B T2 ,A