TOYOTA SUPRA 1995 Service Repair Manual

P. BR±84
P. BR±86 ~ BR±89
P. BR±24
P. BR±86
P. BR±88P. BR±92
P. BR±104 ~ BR±165P. BR±166
Vehicle brought to workshop
Perform troubleshooting in accordance with the procedure on the following pages.
Items insideare titles of pages in this manual,
with the page number in the bottom portion. See the pages
for detailed explanations.
Customer Problem Analysis
Check and Clear Diagnostic Trouble Codes (Precheck)
Symptom
does not occur
Problem Symptom ConfirmationSymptom Simulation
Symptom
occurs
Diagnostic Trouble Code CheckNormal code
Malfunction code
Diagnostic Trouble Code ChartProblem Symptoms Chart
Circuit InspectionSensor CheckCheck for Fluid Leakage
Identification of Problem
Repair
Confirmation Test
EndStepDiagnostic steps permitting the use of the TOYOTA
hand±held tester or TOYOTA break±out box.
HOW TO PROCEED WITH TROUBLESHOOTING
BR±52± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

CUSTOMER PROBLEM ANALYSIS CHECK SHEET
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±53

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)

ECU DATA MONITOR USING TOYOTA
HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Monitor the ECU data by following the prompts on the scan
tool screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function
which records the monitored data.
Please refer to the TOYOTA hand±held tester operator's
manual for further details.
DIAGNOSTIC TROUBLE CODE
CLEARANCE
1. Using SST, connect terminals Tc and E1 of DLC2 or DLC1.
SST 09843±18020
2. IG switch ON.
3. Clear the diagnostic trouble codes stored in ECU by
depressing the brake pedal 8 or more times within 3 seconds.
4. Check that the warning light shows the normal code.
5. Remove the SST from the terminals of DLC2 or DLC1.
6. Connect the Short Pin to DLC1.
HINT: Cancellation can also be done by removing the ECU±B
fuse, but in this case, other memory systems will also be can-
celled out.
ECU TERMINAL VALUES
MEASUREMENT USING TOYOTA
BREAK±OUT±BOX AND TOYOTA
HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester and TOYOTA
break±out±box to the vehicle.
2. Read the ECU input/output values by following the prompts
on the tester screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function.
This records the measured values and is effective in the diag-
nosis of intermittent problems.
Please refer to the TOYOTA hand±held tester/TOYOTA
break±out±box operators manual for further details.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±55

DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the diagnostic trouble code check, check the circuit listed for that
code in the table below and proceed to the relevant page.
HINT: Using SST 09843±18020, connect the terminals Tc and E
1, and remove the short pin.
BR±65
BR±65
BR±71
BR±71
BR±77
BR±77
BR±80
BR±80
BR±83
BR±83
BR±83
BR±83
BR±86
BR±86
BR±88
BR±88
BR±88
BR±88
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF*
OFF*
CodeABS Warning Light
Blinking PatternIndicator
DiagnosisSee pageABS
Warning
LightTRAC
OFF
LightTRAC
Indicator
Light
Open or short in ABS solenoid relay circuit
B+ short in ABS solenoid relay circuit
Open or short in ABS motor relay circuit
B+ short in ABS motor relay circuit
Open or short in TRAC solenoid relay circuit
B+ short in TRAC solenoid relay circuit
Open or short in TRAC motor relay circuit
B+ short in TRAC motor relay circuit
Open or short in ABS actuator solenoid circuit
(SFR circuit)
Open or short in ABS actuator solenoid circuit
(SFL circuit)
Open or short in ABS actuator solenoid circuit
(SRR circuit)
Open or short in ABS actuator solenoid circuit
(SRL circuit)
Open or short in TRAC actuator solenoid circuit
(SMC circuit)
Open or short in TRAC actuator solenoid circuit
(SRC circuit)
Right front wheel speed sensor signal
malfunction
Left front wheel speed sensor signal
malfunction
Right rear wheel speed sensor signal
malfunction
Left rear wheel speed sensor signal
malfunction
BR±56± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

BR±88.
BR±88
BR±92
BR±95
BR±97
BR±98
BR±100
BR±102
BR±104
CodeABS Warning Light
Blinking Pattern
Indicator
DiagnosisSee pageABS
Warning
LightTRAC
Indicator
LightTRAC
OFF
Light
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF*
OFF*
OFF*
OFF*
Always
ON
Open circuit in left front or right rear speed sensor
circuit
Open circuit in right front or left rear speed sensor
circuit
Low battery positive voltage or abnormally high
battery positive voltage
Open or short in lateral acceleration
sensor circuit
ABS pump motor is locked
Open in ABS pump motor ground
Brake fluid reservoir level low
Open circuit in TRAC pump motor circuit
TRAC ECU communication abnormal
Wheel speed sensor signal malfunction
Malfunction in ABS (& TRAC) ECU

: Only vehicles with TRAC
*: When a malfunction causing code No. 17, 18, 55, 58, 61 or 62 is detected, the ABS warning light does
not light up, but the TRAC indicator light does. However, when checking the DTC, check the blinking
pattern of the ABS warning light.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±57

PARTS LOCATION
BR±58± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

Symbols
(Terminals No.)STD Voltage (V)Condition
Always
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light ON
IG switch ON, ABS warning light OFF
IG switch ON, PKB switch ON
IG switch ON, PKB switch OFF
Stop light switch OFF
Stop light switch ON
IG switch ON, ABS warning light OFF
IG switch ON
IG switch ON
IG switch ON
Slowly turn right front wheel
IG switch ON
IG switch ON
IG switch ON
IG switch ON, Vehicle parked on a level surface
IG switch ON, Vehicle parked on a level surface
Slowly turn left front wheel
Slowly turn left rear wheel
Slowly turn left rear wheel
10 ± 14
10 ± 14
9 ± 14
Below 1.0
10 ± 14
10 ± 14
10 ± 14
10 ± 14
10 ± 14
Below 2.0
10 ± 14
Below 1.5
10 ± 14
10 ± 14
10 ± 14
10 ± 14
10 ± 14
Below 1.5
AC generation
AC generation
AC generation
AC generation
4 ± 6
4 ± 6 or 7 ±11
BATGND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
(A19±25)(A19±15)
(A19±12)(A19±2)
IG 1
SRR±
R±MR
(A19±11)(A19±24)
(A19±23)(A19±24)
(A19±1)(A19±2)
SFR
SFL
SRR
SRL
AST
WA
PKB
STP
D/G
Tc
Ts
FR +
FL +
RR +
RL +
GS 1
GS 2
(A19±13)
(A19±26)
(A19±14)
(A19±18)
(A18±13)
(A18±14)
(A18±6)
(A18±4)
(A19±5)
(A18±15)
(A19±16)
(A19±9)
(A18±8)
(A18±9)
(A18±12)
(A18±3)
(A19±2)
(A19±15)
(A19±15)
(A19±15)
(A19±15)
(A19±15)
(A19±2)
(A19±2)
(A19±2)
(A19±15)
(A19±3)
(A19±22)
(A18±16)
(A18±1)
(A19±15)
(A19±2)
FR±
FL±
RR±
RL±
ECU TERMINALS STANDARD VALUE
w/o TRAC:
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±59

Symbols
(Terminals No.)STD Voltage (V)Condition
Always
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, ABS warning light OFF
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON, TRAC and TRAC OFF indicator light OFF
IG switch ON, ABS warning light ON
IG switch ON, ABS warning light OFF
IG switch ON, PKB switch ON
Fluid in M/C reservoir above MIN level.
IG switch ON, PKB switch OFF
Fluid in M/C reservoir above MIN level.
IG switch ON
Fluid in M/C reservoir above MIN level.
Stop light switch OFF
Stop light switch ON
IG switch ON, ABS warning light OFF
BATGND
GND
R±
R±
R±
R±
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
(A20±7)(A20±25)
(A20±24)(A20±25)
(A20±15)(A20±12)
(A20±2)(A20±12)
(A20±12)
(A20±12)
(A22±9)
(A20±25)
(A20±25)
(A22±9)
(A20±25)
(A22±9)
(A22±9)
(A22±4)
(A22±4)
(A20±25)
(A22±4)
(A22±9)
IG 1
SR
MR
TSR
TMR
SFR
SFL
SRR
SRL
AST
SMC
SRC
WA
PKB
LBL
STP
D/G
(A20±1)
(A20±14)
(A22±1)
(A20±13)
(A20±26)
(A22±7)
(A20±21)
(A22±2)
(A22±8)
(A22±5)
(A22±12)
(A20±10)
(A22±6)
(A22±10)
10 ±14
10 ±14
8.3 ±14
Below 1.0
8.3 ±14
Below 1.0
10 ±14
10 ±14
10 ±14
10 ±14
10 ±14
10 ±14
10 ±14
Below 2.0
10 ±14
Below 1.5
10 ±14
10 ±14
Below 1.5
8 ±14
10 ±14
w/ TRAC:
BR±60± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)

Symbols
(Terminals No.)STD Voltage (V)Conditions
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
IG switch ON
Slowly turn right front wheel.
Slowly turn left front wheel.
Slowly turn right rear wheel.
Slowly turn left rear wheel.
Slowly turn right front wheel.
Slowly turn left front wheel.
Slowly turn right rear wheel.
Slowly turn left rear wheel.
IG switch ON, Vehicle parked on a level surface
IG switch ON, Vehicle parked on a level surface
IG switch ON
Pulse generation
Pulse generation
Pulse generation
Pulse generation
AC generation
AC generation
AC generation
TcGND
GNDTs
FR +FR ±
FL +FL ±
RR +RR ±
RL +RL ±
FROGND
FLOGND
RROGND
RLOGND
GS 1GND
GS 2GND
EXOGND
10 ±14
10 ±14
10 ±14
4 ±6
10 ±14
4 ± 6 or 7 ± 11
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±61