Page 73 of 1807

V08423 Knock Sensor 1
GRECM
KNK
E1 12
E6
WIRING DIAGRAM
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detecting Condition Trouble Area
P0325No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more. Open or short in knock sensor1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fall safe function in which the corrective retard angle
value is set to the maximum value.
Diagnostic Trouble Code No. and Detection Item
Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.
Wiring Diagram
This shows a wring diagram of the circuit.
Use the diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wiring colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe. IN-26
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
1997 SUPRA (RM502U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.
Page 93 of 1807
31 SUPRAÐNEW FEATURES
Wiring Diagram
Page 369 of 1807

Manual Name
Pub. No.
(USA and CANADA)
SUPRA Repair Manual
Supra Electrical Wiring Diagram
Manual
1/2 SUPRA New Car Features
(Models except USA and CANADA)
SUPRA Chassis and Body Repair Manual
Supra Electrical Wiring Diagram
Manual
SUPRA New Car Features
(All Countries)
Fundamental Painting Procedures
Fundamental Body Repair ProceduresBRM024E
BRM002E NCF097E RM344E
EWD175Y NCF096U M/Y Version
M/Y Version
FOREWORD
This repair manual has been prepared to provide information on
the repair methods (including cutting and welding operations, but
excluding painting) for collision-damaged body components of the
TOYOTA SUPRA.
Applicable models: JZA80 series
This manual consists of body repair methods, exploded diagrams
and illustrations of the body components and other information re-
lating to body panel replacement such as handling precautions,
etc. However, it should be noted that the front fenders of the
TOYOTA models are bolted on and require no welding.
Body construction will sometimes differ depending on specifica-
tions and country of destination. Therefore, please keep in mind
that the information contained herein is based on vehicles for gen-
eral destinations.
For the repair procedures and specifications other than collisionda-
maged body components of the TOYOTA SUPRA refer to the fol-
lowing repair manuals.
If you require the above manuals, please contact your TOYOTA
Dealer.
All information contained in this manual is the most up-to-date at
the time of publication. However, specifications and procedures are
subject to change without prior notice.
TOYOTA MOTOR CORPORATION
Page 586 of 1807
FI6930
B-W
R/B No.22
2A
EFI No.1 B
BatteryEFI Main RelayB-R R/B No.2
B-Y
W-B
EBEA2
2
22
2 23
5
1
EA1
8
5
1
Mass Air Flow Meter2
5Y-R
B-RA
B
B 66
28
E2G
E1 VG GR24
M-RELB+ ECM
1
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-171
399 Author: Date:
1997 SUPRA (RM502U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect the OBD II scan tool or TOYOTA hand-held tester, and read value of
mass air flow rate.
RESULT:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand-held tester main switch ON.
(c) Start the engine.
CHECK:
Read mass air flow rate on the OBD II scan tool or TOYOTA hand-held tester.
RESULT:
Type IType II
Mass air flow rate0.0 gm / sec.359.0 gm / sec. or more
Type I Go to step 2.
Type II Go to step 5.
Page 589 of 1807
DI-174
- DIAGNOSTICSENGINE (2JZ-GTE)
402 Author: Date:
1997 SUPRA (RM502U)
DTC P0101 Mass Air Flow Circuit Range / Performance
Problem
CIRCUIT DESCRIPTION
Refer to ºMass Air Flow Circuit Malfunctionº on page DI-170.
DTC No.DTC Detecting ConditionTrouble Area
P0101
Conditions (a), (b) and (c) continue with engine speed 900
rpm or less:
(2 trip detection logic)
(a) Closed throttle position switch: ON
(b) Mass air flow meter output > 2.2 V
(c) Engien coolant temp. 70°C
Mass air flow meterP0101
Conditions (a) and (b) continue with engine speed 1,500 rpm or
more:
(2 trip detection logic)
(a) Mass air flow meter output < 1.0 V
(b) VTA 0.72 V
Mass air flow meter
WIRING DIAGRAM
Refer to page DI-170 or the WARNING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0101) being output?
YES Go to relevant DTC chart.
NO
Replace mass air flow meter.
DI4SN-01
Page 591 of 1807

FI6448
Intake Air Temp. Sensor
(Inside the mass air flow meter)
3
4P-L
W-B45
65B
BECM
5V
THAR
E2
E2
DI-176
- DIAGNOSTICSENGINE (2JZ-GTE)
404 Author: Date:
1997 SUPRA (RM502U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC ºP0110º (Intake Air Temp. Circuit Malfunction), ºP0115º (Engine Coolant Temp. Circuit Malfunc-
tion), ºP0120º (Throttle/Pedal Position Sensor/Switch ºAº Circuit Malfunction), are output simulta-
neously, E2 (sensor ground) may be open.
1 Connect the OBD II scan tool or TOYOTA hand-held tester, and read value of in-
take air temperature.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand-held tester main switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA hand-held tester.
OK:
Same as actual intake air temperature.
HINT:
If there is open circuit, OBD II scan tool or TOYOTA hand-held tester indicates - 40°C (- 40°F).
If there is short circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG - 40 °C (- 40 °F) ............. Go to step 2.
140 °C (284 °F) or more .. Go to step 4.
OK
Check for intermittent problems.
(See page DI-147)
Page 594 of 1807

P19603
Engine Coolant Temp. SensorECM
2
1L-Y
W-B44
65B
BTHW
E2R5V
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-179
407 Author: Date:
1997 SUPRA (RM502U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temperature sensor changes the resistance value according to the
engine coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the intake air temperature circuit
malfunction shown on page DI-175.
If the ECM detects the DTC P0115, it operates the fail safe function in which the engine coolant temperature
is assumed to be 80°C (176°F).
DTC No.DTC Detecting ConditionTrouble Area
P0115Open or short in engine coolant temp. sensor circuit
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
HINT:
After confirming DTC P0115 use the OBD II scan tool or TOYOTA hand-held tester to confirm the engine
coolant temperature from ºCURRENT DATAº.
Temperature DisplayedMalfunction
- 40°C (- 40°F)Open circuit
140°C (284°F) or moreShort circuit
WIRING DIAGRAM
DI4SP-01
Page 600 of 1807
FI6879
Throttle Position Sensor
43 2 1L-R
Y
R
W-BB
B
B
B 41
43
64
65VCC
VTA1
IDL1
E2
E1B+ 5V ECM
4
3
2
1 Sub Throttle Position Sensor
L-R
Y-L
GR-R
W-BB 63B 42
VTA2
IDL2
E1B+ 5V
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-185
413 Author: Date:
1997 SUPRA (RM502U)
WIRING DIAGRAM