Page 564 of 1807

FI6914
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-149
377 Author: Date:
1997 SUPRA (RM502U)
2. INSPECT DIAGNOSIS (Normal mode)
(a) Check the MIL.
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter
(See page BE-2).
(2) When the engine is started, the MIL should go off.
If the lamp remains on, the diagnosis system has
detected a malfunction or abnormality in the sys-
tem.
(b) Check the DTC.
NOTICE:
(TOYOTA hand-held tester only): When the diagnosis sys-
tem is switched from normal mode to check mode, it erases
all DTC and freezed frame data recorded in normal mode.
So before switching modes, always check the DTC and
freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand-held tester.
(2) Connect the OBD II scan tool or TOYOTA hand-
held tester to DLC3 at the lower left of the instru-
ment panel.
(3) Turn the ignition switch ON and turn the OBD II scan
tool or TOYOTA hand-held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand-held
tester to check the DTC and freezed frame data,
note them down. (For operating instructions, see
the OBD II scan tool's instruction book.)
(5) See page DI-158 to confirm the details of the DTC.
NOTICE:
When simulating symptoms with an OBD II scan tool (ex-
cluding TOYOTA hand-held tester) to check the DTC, use
normal mode. For codes on the DTC chart subject to º2 trip
detection logicº, turn the ignition switch OFF after the
symptom is simulated the first time. Then repeat the simu-
lation process again. When the problem has been simu-
lated twice, the MIL lights up and the DTC are recorded in
the ECM.
3. INSPECT DIAGNOSIS (Check Mode)
Page 569 of 1807
P11288P11833A03032
TE1
E1
SST
DLC1
DI-154
- DIAGNOSTICSENGINE (2JZ-GTE)
382 Author: Date:
1997 SUPRA (RM502U)
6 Check ignition timing.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Shift transmission into ºNº position.
(c) Keep the engine speed at idle.
(d) Using SST, connect terminals TE1 and E1 of DLC 1.
SST 09843-18020
(e) Using a timing light, connect the tester to check wire
(See page EM-1 1).
CHECK:
Check ignition timing.
OK:
Ignition timing: 10 ± 2° BTDC at idle
NG Proceed to IG-1 and continue to
troubleshoot.
OK
Proceed to matrix chart of problem symp-
toms on page DI-169.
Page 573 of 1807

DI4SI-01
DI-158
- DIAGNOSTICSENGINE (2JZ-GTE)
386 Author: Date:
1997 SUPRA (RM502U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code listed
in the table below. For details of each code, turn to the page reffered to under the ºSee pageº for the respec-
tive ºDTC No.º in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P0100
(DI-170)Mass Air Flow Circuit
MalfunctionOpen or short in mass air flow meter circuit
Mass air flow meter
ECM
P0101
(DI-174)Mass Air Flow Circuit
Range / Performance ProblemMass air flow meter
P0110
(DI-175)Intake Air Temp. Circuit
MalfunctionOpen or short in intake air temp. sensor circuit
Intake air temp. sensor
ECM
P0115
(DI-179)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
P0116
(DI-183)Engine Coolant Temp. Circuit
Range / Performance ProblemEngine coolant temp. sensor
Cooling system
P0120
(DI-184)Throttle / Pedal Position
Sensor / Switch ºAº Circuit
MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM
P0121
(DI-189)Throttle /Pedal Position
Sensor / Switch ºAº Circuit
Range / Peformance Problem
Throttle position sensor
P0125
(DI-190)Insufficient Coolant Temp. for
Closed Loop Fuel ControlOpen or short in heated oxygen sensor circuit
Heated oxygen sensor
P130
(DI-193)Heated Oxygen Sendor Circuit
Malfunction
(Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
P0133
(DI-196)Heated Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)
Heated oxygen sensor
*: ... MIL lights up
Page 608 of 1807

FI7130
Vehicle speed
50 - 65 km/h
(31 - 40 mph)
Idling
IG SW OFF(5) (3)
(1) (2)
1 - 3 min.1 min.
Time
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-193
421 Author: Date:
1997 SUPRA (RM502U)
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to ºInsufficient Coolant Temp. for Closed Loop Fuel Controlº on page DI-190.
DTC No.DTC Detecting ConditionTrouble Area
P0130
Voltage output of heated oxygen sensor remains at 0.4 V or
more, or 0.55 V or less, during idling after the engine is
warmed up (2trip detection logic)Heated oxygen sensor
Fuel trim malfunction
HINT:
Bank 1 refers to the bank that includes cylinder No.1.
Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor output voltage and the short-term fuel trim value can be read using the OBD II
scan tool or TOYOTA hand-held tester.
WIRING DIAGRAM
Refer to page DI-190 for the WIRING DIAGRAM.
CONFIRMATION DRIVING PATTEN
(1) Connect the TOYOTA hand-held tester to the DLC3.
(2) Switch the TOYOTA hand-held tester from normal mode to check mode (See page DI-147).
(3) Start the engine and warm it up with all accessory switches OFF.
(4) Drive the vehicle at 50 - 65 km/h (31 - 40 mph) for 1 - 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a TOYOTA hand-held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI4SU-01
Page 616 of 1807

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-201
429 Author: Date:
1997 SUPRA (RM502U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
ºFuel trimº refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short-term fuel trim and long-term fuel trim.
ºShort-term fuel trimº is the short-term fuel compensation used to maintain the air-fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air-fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air-fuel ratio is rich,
and an increase in fuel volume if it is lean.
ºLong-term fuel trimº is overall fuel compensation carried out long-term to compensate for continual devi-
ation of the short-term fuel trim from the central value due to individual engine differences, wear over time
and changes in the usage environment.
If both the short-term fuel trim and long-term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the RICH side
(2 trip detection logic)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
P0172
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the LEAN side
(2 trip detection logic)
Fuel line pressure
Injector blockage, leak
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
HINT:
When DTC P0171 is recorded, the actual air-fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air-fuel ratio is on the RICH side.
If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.
If the total of the short-term fuel trim value and long-term fuel trim value is within ± 35 %, the system
is functioning normally.
INSPECTION PROCEDURE
1 Check air induction system (See page SF-1).
NG Repair or replace.
OK
DI4SY-01
Page 631 of 1807

P20769
70 - 90 km/h
(43 - 56 mph)
Idling
IG SW OFF
Warm up
3 - 5 min.
2 min.3 - 5 min.
2 min.Time
(7) (6)
(5) (7) (3)
(2) (1) DI-218
- DIAGNOSTICSENGINE (2JZ-GTE)
446 Author: Date:
1997 SUPRA (RM502U)
SYSTEM CHECK DRIVING PATTERN
(1) Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(2) Start the engine and warm it up with all accessories switched OFF.
(3) Run the vehicle at 70 - 90 km/h (43 - 56 mph) for 3 min. or more.
(4) Idle the engine for about 2 min.
(5) Stop at safe place and turn the ignition switch OFF.
(6) Start the engine and do steps (3) and (4) again.
(7) Check the ºREADINESS TESTSº mode on the OBDII scan tool or TOYOTA hand-held tester. If ºCOMPLº
is displayed and the MIL does not light up, the system is normal. If ºINCMPLº is displayed and the MIL does
not light up, run the vehicle again and check it.
HINT:
ºINCMPLº is displayed when either condition (a) or (b) exists.
The system check is incomplete.
There is a malfunction in the system.
If there is a malfunction in the system, the MIL will light up after steps (2) to (6) above are done.
Page 645 of 1807

FI7132
Engine Speed
2,500 - 3,000 rpm
Idling
IG SW OFF
Warmed up 3 min. or so CheckTime (1)(2)(3) (4)
FI6514
OX Signal Waveform (Oscilloscope)
200 msec./Division 1.0 V
0 V DI-232
- DIAGNOSTICSENGINE (2JZ-GTE)
460 Author: Date:
1997 SUPRA (RM502U)
CONFIRMATION ENGINE RACING PATTERN
(1) Connect the TOYOTA hand-held tester to the DLC3, or connect the probe of the oscilloscope between
terminals OX1, OX2, and E1 of ECM.
(2) Start engine and warm it up with all accessories switched OFF until water temperature is stable.
(3) Race the engine at 2,500 ~ 3,000 rpm for about 3 min.
(4) After confirming that the waveforms of the heated oxygen sensors, bank 1 sensor 1 (OX1), oscillate
around 0.5 V during feedback to the ECM, check the waveform of the heated oxygen senor, bank 1 sensor
2 (OX2).
HINT:
If there is a malfunction in the system, the waveform of the
heated oxygen senor, bank1 sensor 2 (OX2), is almost the
same as that of the heated oxygen sensors, bank 1 senor 1
(OX1), on the left.
There are some cases where, even though a malfunction ex-
ists, the MIL may either light up or not light up.
Page 695 of 1807

A00726
ON
ONBrake Pedal
DepressedBrake Pedal
Released
Check Harness A
ECM
A4
STP(+)
DI-280
- DIAGNOSTICSENGINE (2JZ-GTE)
508 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check operation of stop light.
PREPARATION:
Check if the stop lights go on and off normally when the brake
pedal is operated and released.
NG Check and repair stop light circuit.
OK
2 Check STP signal.
When using TOYOTA hand-held tester:
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and TOYOTA hand-held tes-
ter main switch ON.
CHECK:
Read the STP signal on the TOYOTA hand-held tester.
OK:
Break pedal is depressed: STP ... ON
Break pedal is released: STP ... OFF
When not using TOYOTA hand-held tester:
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Check voltage between terminal STP of ECM and body ground.
OK:
Brake pedalVoltage
Depressed7.5 - 14 V
ReleasedBelow 1.5 V
OK Check for intermittent problems
(See page DI-147).
NG