1995 TOYOTA SUPRA ignition

  ANTENNA MOTOR CONTROL RELAY (Wire Harness Side) 
  1 ± Ground (Constant) Battery positive voltage
  4 ± Ground (Ignition SW position ON) Battery positive voltage 
  5 ± Ground (Ignition SW position ACC or ON)
 
 Battery positive voltage
  7 ± Ground (Ignition SW position ACC or ON and radio SW ON) Battery positive voltage
  8 ± Ground (Ignition SW position ACC or ON) Battery positive voltage
± BODY ELECTRICAL SYSTEMSERVICE SPECIFICATIONSBE±203

GENERAL INFORMATION
HANDLING PRECAUTIONS
Taping
When it is possible that the body or parts may be scratched
during the operation, apply protective tape before starting
work.
Example:
1. Before starting work, apply protective tape to body
surfaces around parts to be removed and installed.
2. Before prying parts loose with a screwdriver or scraper
etc., apply protective tape to the tip of the tool to avoid
scratching parts or painted surfaces of the body.
Battery
In order to prevent a short circuit while doing work on the elec-
trical circuit such as disconnecting a connector, first turn off
the ignition switch and disconnect the negative (±) terminal
cable from the battery before starting work.
HINT: When battery voltage is required for operation of a
functioning part, connect the cable to the battery when need-
ed, and promptly disconnect it when no longer necessary.
CAUTION:
wWork must be started after 90 seconds from the time the
ignition switch is turned to the ºLOCKº position and the
negative (±) terminal cable is disconnected from the
battery.
wTo avoid erasing the memory of each memory system,
never use a back±up power supply from outside the
vehicle.
Fitting Adjustments
When removing and installing body panels which have a pre-
load value, after installation refer to the page containing the
installation adjustment methods, and make adjustments ac-
cording to the required specifications.
HINT: When making adjustments, do not completely loosen
the bolts and nuts of the part being adjusted. Tighten them
appropriately, and move the panels by hand to align them. BO±2
± BODYGENERAL INFORMATION

SRS (Supplemental Restraint System)
The 1995 SUPRA is equipped with an SRS, such as the driver airbag and front passenger airbag assembly.
Failure to carry out service operations in the correct sequence could cause the SRS to deploy, possibly
leading to a serious accident.
When removing or installing of airbag parts and the yellow wire harness and connector for the airbag is
necessary, refer to the precautionary notices in the RS section before performing the operation.
wWork must be started after 90 seconds from the time the ignition switch is set to the LOCK position
and the negative (±) terminal cable is disconnected from the battery.
(The SRS is equipped with a back±up power source so that if work is started within 90 seconds of
disconnecting the negative (±) terminal cable of the battery, the SRS may deploy.)
wTo avoid erasing the memory of each memory system, never use a back±up power supply from
outside the vehicle.
wBefore repairs, remove the airbag sensors if shocks are likely to be applied to the sensors during
repairs.
wThe front airbag sensor set bolt has been anti±rust treated. When the sensor is removed, always
replace the set bolt with a new one.
wIf the front airbag sensors, center airbag sensor assembly, steering wheel pad or front passenger
airbag assembly have been dropped, or if there are cracks, dents or other defects in the case, bracket
or connector, replace them with new ones.
wNever use SRS parts from another vehicle. When replacing parts, replace them with new parts.
wDo not expose the front airbag sensors, center airbag sensor assembly, steering wheel pad or front
passenger airbag assembly directly to hot air or flames.
wThe SRS wire harness is integrated with the cowl wire harness assembly. The wires for the SRS wire
harness are encased in a yellow corrugated tube. All the connectors for the system are also a standard
yellow color. If the SRS wire harness becomes disconnected or the connector becomes broken due
to an accident, etc., repair or replace it. (See RS section)
wThe steering wheel must be fitted correctly to the steering column with the spiral cable at the neutral
position; otherwise, cable disconnection and other troubles may result. Refer to RS section of this
manual concerning correct steering wheel installation.
wWhen removing or handling the steering wheel pad or front passenger airbag assembly, it should be
placed with their top surface facing up. In this case, the twin±lock type connector lock lever should
be in the locked state and care should be taken to place it so the connector will not be damaged.
(Storing the pad with its metallic surface up, the front passenger airbag assembly with the airbag door
facing down may lead to a serious accident if the airbag inflates for some reason.)
wGrease should not be applied to the steering wheel pad or the front passenger airbag assembly, and
they should not be cleaned with detergents of any kind.
wStore the steering wheel pad or the front passenger airbag assembly where the ambient temperature
remains below 93°C (200°F), without high humidity and away from electrical noise.
wInformation labels are attached to the periphery of the SRS components. Follow the notices.
wWhen the ignition switch is at ACC or ON and the SRS warning light remains on, the center airbag
sensor assembly has detected a malfunction code. (See RS section)
± BODYGENERAL INFORMATIONBO±5

DIAGNOSIS SYSTEM
INDICATOR CHECK
When the ignition switch is turned ON, check that the ABS
warning light goes on for 3 seconds.
HINT: If the indicator check result is not normal, proceed to
troubleshooting for the ABS warning light circuit (See page
BR±107)
DIAGNOSTIC TROUBLE CODE CHECK
1. Turn the ignition switch ON.
2. Disconnect the Short Pin from DLC1.
3. Using SST, connect terminals Tc and E1 of DLC2 or DLC1.
SST 09843±18020
4. Read the diagnostic trouble code from the ABS warning light
on the combination meter.
HINT: If no code appears, inspect the diagnostic circuit or
ABS warning light circuit (See page BR±112 or BR±107).
As an example, the blinking patterns for normal code and
codes 11 and 21 are shown on the left.
5. Codes are explained in the code table on page BR±56.
6. After completing the check, disconnect terminals Tc and E1,
and turn off the display.
If 2 or more malfunctions are indicated at the same time, the
lowest numbered diagnostic trouble code will be displayed
first. BR±54
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

SPEED SENSOR SIGNAL CHECK
1. Turn the ignition switch OFF
2. Using SST, connect terminals Ts and E1 of DLC1.
SST 09843±18020
3. Start the engine.
4. Check that the ABS warning light blinks.
HINT:
wIf the ABS warning light does not blink, inspect the ABS
warning light circuit (See page BR±107).
wIf the ABS warning light is always on, inspect and repair
the IG1 terminal of lateral acceleration sensor.
5. Drive the vehicle faster than 45 km/h (28 mph) for several
seconds.
6. Stop the vehicle.
7. Using SST, connect terminals Tc and E1 of DLC1.
SST 09843±18020
8. Read the number of blinks of the ABS warning light.
HINT: See the list of diagnostic trouble codes shown on the
next page.
If every sensor is normal, a normal code is output (A cycle of
0.25 sec. ON and 0.25 sec. OFF is repeated).
If 2 or more malfunctions are indicated at the same time, the
lowest numbered code will be displayed first.
9. After doing the check, disconnect terminals Ts and E1, Tc and
E1 of DLC1, and turn ignition switch OFF. BR±62
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

CIRCUIT INSPECTION
DTC 11 12 ABS Solenoid Relay Circuit
CIRCUIT DESCRIPTION
This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is OK,
the relay goes on.
 
 DTC No.
 
 Diagnostic Trouble Code Detecting Condition
 
 Trouble area
 
 
 
 
 
11
 
 
 
 
 
Conditions (1) and (2) continue for 0.2 sec.
or more:
(1) ABS solenoid relay terminal (SR)
voltage: Battery positive voltage
(2) Solenoid relay monitor terminal (AST)
voltage: O V 
 
 
 
 

ABS solenoid relay

Open or short in ABS solenoid relay circuit

ECU
 
 
 
 
 
12
 
 
 
 
 
Conditions (1) and (2) continue for 0.2 sec.
or more:
(1) ABS solenoid relay terminal (SR)
voltage: O V
(2) Solenoid relay monitor terminal (AST)
voltage: Battery positive voltage 
 
 
 
 

ABS solenoid relay

B+ short in ABS solenoid relay circuit

ECU
Fail safe function: If trouble occurs in the solenoid relay circuit, the ECU cuts off current to the solenoid relay
and prohibits ABS control.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±65

DTC 15 16 TRAC Solenoid Relay Circuit
CIRCUIT DESCRIPTION
This relay circuit supplies power to each traction actuator solenoid.
When the ignition switch is turned ON, the relay goes on.
 DTC No. Diagnostic Trouble Code Detecting Condition Trouble area 
 
 
 
 
 
 
15
 
 
 
 
 
 
 
Conditions (1) through (3) continue for 0.2
sec. or more:
(1) TRAC solenoid relay terminal (TSR)
voltage: Battery positive voltage
(2) All TRAC actuator solenoids: OFF
(3) All TRAC actuator solenoid monitor
voltages (in ECU): 0 V 
 
 
 
 
 
 

TRAC solenoid relay

Open or short in TRAC solenoid relay circuit

ECU
 
 
 
 
 
 
16
 
 
 
 
 
 
Conditions (1) through (3) continue for 0.2
sec. or more:
(1) TRAC solenoid relay terminal (TSR)
voltage: 0 V
(2) All TRAC actuator solenoids: OFF
(3) TRAC actuator solenoid monitor voltage
(in ECU): Battery positive voltage 
 
 
 
 
 

TRAC solenoid relay

B+ short in TRAC solenoid relay circuit

ECU
Fail safe function: If trouble occurs in this relay circuit, the ECU cuts off current to the ABS and TRAC solenoid
relays and prohibits ABS and TRAC control.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±77

CIRCUIT DESCRIPTION
The speed sensor detects the wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
both the ABS and TRAC control systems. The front and rear ro-
tors each have 48 serrations. When the rotors rotate, the mag-
netic field emitted by the permanent magnet in the speed sensor
generates an AC voltage. Since the frequency of this AC volt-
age changes in the direct proportion to the speed of the rotor,
the frequency is used by the ECU to detect the speed of each
wheel.
31, 32
33, 34
35
36
Detection of any of conditions (1) through (3):
(1) At vehicle speed of 10 km/h (6 mph) or
more, pulses are not input for 5 sec.
(2) Momentary interruption of he vehicle
speed sensor signal occurs at least 7
times in the time between switching the
ignition switch ON and switching it OFF.
(3) Abnormal fluctuation of speed sensor sig±
nals with the vehicle speed 20 km/H (12
mph) or more.
Speed sensor signal is not input for about 1
sec. while the left front and right rear speed
sensor signals are being checked with the IG
switch ON.
Speed sensor signal is not input for about 1
sec. while the right front and left rear speed
sensor signals are being checked with the IG
switch ON.

Right front, left front, right rear and left rear
speed sensor.

Open or short in each speed sensor circuit.

ECU

Open in left front, right rear speed sensor
circuit.

ECU

Open in right front, left rear speed sensor
circuit.

ECU
HINT: DTC No.31 is for the right front speed sensor.
DTC No. 32 is for the left front speed sensor.
DTC No.33 is for the right rear speed sensor.
DTC No.34 is for the left rear speed sensor.
Fail safe function: If trouble occurs in the speed sensor circuit, the ECU cuts off current to the ABS
solenoid relay and prohibits ABS control.
DTC 31 32 33 34 35 36 Speed Sensor Circuit
BR±88± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)