1997 TOYOTA SUPRA ESP

9
B
The ground points circuit diagram shows the connections from all major parts to the respective ground points.
When troubleshooting a faulty ground point, checking the system circuits which use a common ground may
help you identify the problem ground quickly. The relationship between ground points ( , and
shown below) can also be checked this way.
EAIBIC
* The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.
J GROUND POINT

17
E GLOSSARY OF TERMS AND SYMBOLS
METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to
move, thereby providing a relative
display against a background
calibration. LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes
emit light without producing the
heat of a comparable light. IGNITION COIL
Convert low-voltage DC current
into high-voltage ingition current
for firing the spark plugs.
1. SINGLE
FILAMENT
GROUND
The point at which wiring attaches
to the Body, thereby providing a
return path for an electrical circuit;
without a ground, current cannot
flow.
Current flow causes a headlight
filament to heat up and emit light.
A headlight may have either a
single (1) filament or a double (2)
filament. BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the
auto's various electrical circuits.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it.
Some units automatically reset when
cool, others must be manually reset.
DIODE
A semiconductor which allows
current flow in only one direction.
DIODE, ZENER
A diode which allows current
flow in one direction but blocks
reverse flow only up to a specific
voltage. Above that potential, it
passes the excess voltage.
This acts as a simple voltage
regulator.
PHOTODIODE
The photodiode is a
semiconductor which controls the
current flow according to the
amount of light.
FUSE
A thin metal strip which burns
through when too much current
flows through it, thereby stop-
ping current flow and protecting a
circuit from damage.
FUSIBLE LINK
A heavy-gauge wire placed in
high amperage circuits which
burns through on overloads,
thereby protecting the circuit.
The numbers indicate the cross-
section surface area of the wires.HORN
An electric device which sounds a
loud audible signal.
LIGHT
Current flow through a filament
causes the filament to heat up
and emit light.
METER, DIGITAL
Current flow activates one or
many LED's, LCD's, or fluoresent
displays, which provide a relative
or digital display.
MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion. CIGARETTE LIGHTER
An electric resistance heating
element.
DISTRIBUTOR, IIA
Channels high-voltage current
from the ignition coil to the
individual spark plugs.
2. DOUBLE
FILAMENT
HEADLIGHTS
FUEL
M
(for High Current Fuse or
Fusible Link.)
(for Medium Current Fuse)

71
2. CONTROL SYSTEM
*SEQUENTIAL MULTIPORT FUEL INJECTION SYSTEM
THE SEQUENTIAL MULTIPORT FUEL INJECTION SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE
SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL
MODULE. THE BEST FUEL INJECTION TIMING IS DECIDED BASED ON THIS DATA AND THE PROGRAM
MEMORIZED BY THE ENGINE CONTROL MODULE, AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10,
#20, #30, #40, #50 AND #60 OF THE ENGINE CONTROL MODULE TO OPERATE THE INJECTOR (INJECT THE FUEL).
THE SEQUENTIAL MULTIPORT FUEL INJECTION SYSTEM PRODUCES CONTROLS OF FUEL INJECTION
OPERATION BY THE ENGINE CONTROL MODULE IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE
CONTROL MODULE FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO (13) ETC.). THE BEST IGNITION
TIMING IS DECIDED ACCORDING TO THIS DATA AND THE MEMORIZED DATA IN THE ENGINE CONTROL MODULE
AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5 AND IGT6 THESE SIGNALS
CONTROL THE IGNITER TO PROVIDE THE BEST IGNITION TIMING FOR THE DRIVING CONDITIONS.
*HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM
THE MAIN HEATED OXYGEN SENSOR, SUB HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM TURNS THE
HEATER ON WHEN THE INTAKE AIR VOLUME IS LOW (TEMP. OF EXHAUST EMISSIONS IS LOW) AND WARMS UP
THE OXYGEN SENSOR TO IMPROVE DETECTION PERFORMANCE OF THE SENSOR. THE ENGINE CONTROL
MODULE EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4), (9) TO (11) ETC.),
AND OUTPUTS CURRENT TO TERMINALS HT1, HTS TO CONTROL THE HEATER
*IDLE AIR CONTROL SYSTEM
THE IDLE AIR CONTROL SYSTEM (STEP MOTOR TYPE) INCREASES THE ENGINE SPEED AND PROVIDES IDLING
STABILITY FOR FAST IDLE-UP WHEN THE ENGINE IS COLD, AND WHEN THE IDLE SPEED HAS DROPPED DUE TO
ELECTRICAL LOAD AND SO ON. THE ENGINE CONTROL MODULE EVALUATES THE SIGNALS FROM EACH
SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9), (11) ETC.), OUTPUTS CURRENT TO TERMINALS ISC1, ISC2,
ISC3 AND ISC4 TO CONTROL THE IDLE AIR CONTROL VALVE.
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10)
ETC.), AND OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE OUTPUTS CURRENT TO TERMINAL FPC AND CONTROLS THE FUEL PUMP ECU
AND FUEL PUMP DRIVE SPEED IN RESPONSE TO THE DRIVING CONDITIONS
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE SIGNAL
SYSTEM, THE MALFUNCTIONING SYSTEM IS RECORDED IN THE MEMORY. THE MALFUNCTIONING SYSTEM CAN BE
FOUND BY READING THE CODE DISPLAYED BY THE MALFUNCTION INDICATOR LAMP.
4. FAIL-SAFE SYSTEM
WHEN A MALFUNCTION HAS OCCURRED 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 MEMORY OR ELSE STOPS THE ENGINE.

145
AND A/T INDICATOR (2JZ-GTE)
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 FROM THE ENGINE COOLANT TEMP. SENSOR AND THE VEHICLE SPEED SIGNAL FROM
VEHICLE SPEED SENSOR NO. 2 IS INPUT TO TERMINAL (B) 23 OF THE ENGINE CONTROL MODULE. 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 AS THROTTLE ANGLE SIGNAL.
BASED ON THESE SIGNALS, THE ENGINE CONTROL 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 "TERMINAL 4 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID"GROUNDAND
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 "TERMINAL 8 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "GROUND AND FROM
TERMINAL (B) 10 OF THE ENGINE CONTROL MODULE "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 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
ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "TERMINAL 7"TERMINAL (B) 14 OF THE ENGINE
CONTROL MODULE "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. THE ENGINE CONTROL MODULE 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, 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 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 SWITCHED FROM NORMAL
TO MANUAL, A SIGNAL IS INPUT TO TERMINAL (A) 18 OF THE ENGINE CONTROL MODULE. INPUT OF THIS SIGNAL
CAUSES CURRENT TO FLOW FROM THE GAUGE FUSE TO TERMINAL (A) 1 OF THE COMBINATION METER "
TERMINAL (A) 12"TERMINAL (A) 25 OF THE ENGINE CONTROL MODULE "GROUND, LIGHTING UP THE
INDICATOR LIGHT. IF THE A/T SHIFT LEVER IS THEN SHIFTED TO 2`' POSITION, THE ENGINE CONTROL MODULE
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 FROM CRUISE CONTREOL ECU. AS A RESULT, THE ENGINE CONTROL MODULE OPERATES
AND CONTROLS OVERDRIVE, LOCK-UP AND SO ON FOR SMOOTH DRIVING.
SYSTEM OUTLINE

155
AND A/T INDICATOR (2JZ-GE)
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 FROM THE ENGINE COOLANT TEMP. SENSOR AND THE VEHICLE SPEED SIGNAL FROM
VEHICLE SPEED SENSOR NO. 2 IS INPUT TERMINAL (B) 23 OF THE ENGINE CONTROL MODULE. 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 AS THROTTLE ANGLE SIGNAL.
BASED ON THESE SIGNALS, THE ENGINE CONTROL MODULE 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  TERMINAL 1 OF THE 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  TERMINAL 2 OF ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID  GROUND, AND
FROM TERMINAL (B) 10 OF THE ENGINE CONTROL MODULE  TERMINAL 1 OF THE 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 JUDGES FROM EACH SIGNAL THAT LOCK-UP OPERATION CONDITIONS
HAVE BEEN MET, THE CURRENT FLOWS FROM TERMINAL (B) 8 OF THE ENGINE CONTROL MODULE  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. THE ENGINE CONTROL MODULE 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 AND THE ELECTRONICALLY CONTROLLED TRANSMISSION CAUSES SHIFT TO
OVERRIDE 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 THROUGHTHE 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 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 SWITCHED FROM NORMAL
TO MANUAL, A SIGNAL IS INPUT TO TERMINAL (A) 18 OF THE ENGINE CONTROL MODULE. INPUT OF THIS SIGNAL
CAUSES CURRENT TO FLOW FROM THE GAUGE FUSE TO TERMINAL (A) 1 OF THE COMBINATION METER 
TERMINAL (A) 12 TERMINAL (A) 25 OF THE ENGINE CONTROL MODULE  GROUND, LIGHTING UP THE
INDICATOR LIGHT. IF THE A/T SHIFT LEVER IS THEN SHIFTED TO 2º POSITION, THE ENGINE CONTROL MODULE
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 FROM CRUISE CONTROL ECU. AS A RESULT, THE ENGINE CONTROL MODULE OPERATES AND
CONTROLS OVERDRIVE, LOCK-UP AND SO ON FOR SMOOTH DRIVING.
SYSTEM OUTLINE

162
ABS (W/O TRACTION CONTROL)
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 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.
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 CONTINUITY
(B) 5-(A) 4:33

(B) 1,(B) 2,(B) 4,(A) 4:APPROX. 8.8

(B) 5,(B) 6,(B) 8,(A) 4:APPROX. 4.3

A10, A11 ABS SPEED SENSOR FRONT LH, RH
1-2:1.4-1.8 K
(20
C, 68
F)
A31, A32 ABS SPEED SENSOR REAR LH, RH
1-2:0.9-1.3 K
(20
C, 68
F)
A18, (B), A19(A) ABS ECU
(B) 2-GROUND :10-14 VOLTS WITH THE IGNITION SW ON
(B)12-GROUND :10-14 VOLTS WITH THE STOP LIGHT SW ON (BRAKE PEDAL DEPRESSED)
(A) 2, (A) 13-GROUND :ALWAYS CONTINUITY
(A) 1, (A) 4, (A) 10, (A) 11, (A) 21, (A) 22-GROUND:10-14 VOLTS WITH THE IGNITION SW ON
S11 STOP LIGHT SW
1-2:CLOSED WITH THE BRAKE PEDAL DEPRESSED
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
A 6A26(2JZ-GE)A1126(2JZ-GE)D 126(2JZ-GE)
A 7B26(2JZ-GE)A18B28D 528
A 8A26A19A28S1129
A 9B26A3130T 529
A1026(2JZ-GE)A3230
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
222R/B NO. 2 (ENGINE COMPARTMENT LEFT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
1I20COWL WIRE AND J/B NO 1 (LEFT KICK PANEL)1K20COWL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
SYSTEM OUTLINE
SERVICE HINTS

166
ABS (W/ TRACTION CONTROL)
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
(3) SPEED SENSOR SIGNAL
THE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS
ECU.
(4) STOP LIGHT SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN THE BRAKE PEDAL IS DEPRESSED.
(5) DECELERATION SENSOR SIGNAL
LONGITUDINAL AND 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.
A20 (A), A21 (B) ABS ECU
(A) 13-GROUND::10-14 VOLTS WITH THE IGNITION SW AT ON POSITION
(A) 5-GROUND:10-14 VOLTS WITH THE STOP LIGHT SW ON
(A) 12,(A) 25-GROUND:ALWAYS CONTINUITY
A 6 (A), A 7 (B) ABS ACTUATOR
(A) 1-GROUND:ALWAYS CONTINUITY
(A) 5-(A) 4.33 W
(B) 1, (B) 2, (B) 3, (B) 4- (A) 4,:APPROX. 8 8 W
(B) 5, (B) 6, (B) 7, (B) 8- (A) 4,:APPROX. 4.3 W
S11 STOP LIGHT SW
2-1:CLOSED WITH THE BRAKE PEDAL DEPRESSED
A10, A11 ABS SPEED SENSOR FRONT LH, RH
1-2:0.4-1.8 K W (20
C, 68
F)
A31, A32 ABS SPEED SENSOR REAR LH, RH
1-2:0.9-1.3 K W (20
C, 68
F)
SYSTEM OUTLINE
SERVICE HINTS

177
7. AUTO CANCEL FUNCTION
A) IF ANY OF THE FOLLOWING OPERATING CONDITIONS OCCUR DURING CRUISE CONTROL OPERATION, THE SET
SPEED IS ERASED, CURRENT FLOW TO MAGNETIC CLUTCH IS STOPPED AND THE CRUISE CONTROL IS
RELEASED. (MAIN SW TURNS OFF).
WHEN THIS OCCURS, THE IGNITION SW MUST BE TURNED OFF ONCE BEFORE THE MAIN SW WILL TURN ON.
*OVER CURRENT TO TRANSISTOR DRIVING MOTOR AND/OR MAGNETIC CLUTCH.
*WHEN CURRENT CONTINUED TO FLOW TO THE MOTOR INSIDE THE ACTUATOR IN THE THROTTLE VALVE
OPENº DIRECTION.
*OPEN CIRCUIT IN MAGNETIC CLUTCH.
*MOMENTARY INTERRUPTION OF VEHICLE SPEED SIGNAL.
*SHORT CIRCUIT IN CRUISE CONTROL SW.
*MOTOR DOES NOT OPERATE DESPITE THE MOTOR DRIVE SIGNAL BEING OUTPUT.
B) IF ANY OF THE FOLLOWING CONDITIONS OCCUR DURING CRUISE CONTROL OPERATION, THE SET SPEED IS
ERASED AND THE CRUISE CONTROL IS RELEASED. (THE POWER OF MAGNETIC CLUTCH IS CUT OFF UNTIL
THE SET SW IS ONº AGAIN.)
*WHEN THE VEHICLE SPEED FALLS BELOW THE MINIMUM SPEED LIMIT, APPROX. 40 KM/H (25 MPH)
*WHEN THE VEHICLE SPEED FALLS MORE THAN 16 KM/H (10 MPH) BELOW THE SET SPEED, E.G. ON AN
UPWARD SLOPE.
*WHEN POWER TO THE CRUISE CONTROL SYSTEM IS MOMENTARILY CUT OFF.
8. AUTOMATIC TRANSMISSION CONTROL FUNCTION
*IN OVERDRIVE. IF THE VEHICLE SPEED BECOMES LOWER THAN THE OVERDRIVE CUT SPEED (SET SPEED
MINUS APPROX. 4 KM/H, 2.5 MPH) DURING CRUISE CONTROL OPERATION, SUCH AS DRIVING UP A HILL, THE
OVERDRIVE IS RELEASED AND THE POWER INCREASED TO PREVENT A REDUCTION IN VEHICLE SPEED.
*AFTER RELEASING THE OVERDRIVE, VEHICLE SPEED BECOMES HIGHER THAN THE OVERDRIVE RETURN
SPEED (SET SPEED MINUS APPROX, 2 KM/H, 1.2 MPH) AND THE ECU JUDGES BY THE SIGNALS FROM
POTENTIOMETER OF THE ACTUATOR THAT THE UPWARD SLOPE HAS FINISHED, OVERDRIVE IS RESUMED
AFTER APPROXIMATELY 2 SECONDS.
*DURING CRUISE CONTROL DRIVING, THE CRUISE CONTROL OPERATION SIGNAL IS OUTPUT FROM THE
CRUISE CONTROL ECU TO THE ENGINE CONTROL MODULE. UPON RECEIVING THIS SIGNAL, THE ENGINE
CONTROL MODULE CHANGES THE SHIFT PATTERN TO NORMAL. TO MAINTAIN SMOOTH CRUISE CONTROL
OPERATION (ON A DOWNWARD SLOPE ETC.), LOCK-UP RELEASE OF THE TRANSMISSION WHEN THE IDLING
POINT OF THE THROTTLE POSITION IS ONº IS FORBIDDEN.
C 4 CRUISE CONTROL ACTUATOR
3-4 : APPROX. 38.5 W
C14 CRUISE CONTROL SW [COMB. SW]
15-17 : CONTINUITY WITH THE MAIN SW ON
5-17 : APPROX. 418 W WITH THE CANCEL SW ON
APPROX. 68 W WITH THE RESUME/ACCEL SW ON
APPROX. 198 W WITH THE SET/COAST SW ON
C16 CRUISE CONTROL ECU
14-GROUND : APPROX. 12 VOLTS WITH THE IGNITION SW AT ON POSITION
15-GROUND : ALWAYS APPROX. 12 VOLTS
20-GROUND :4 PULSE WITH 1 ROTATION OF ROTOR SHAFT
18-GROUND : APPROX. 418 W WITH THE CANCEL SW ON IN CONTROL SW
APPROX. 198 W WITH THE SET/COAST SW ON IN CONTROL SW
APPROX. 68 W WITH THE RESUME/ACCEL SW ON IN CONTROL SW
13-GROUND : ALWAYS CONTINUITY
SERVICE HINTS