1997 TOYOTA SUPRA ECO mode

DI4SH-01
FI0534
Q08242
TOYOTA Hand-Held Tester
DLC3
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-147
375 Author
: Date
:
1997 SUPRA (RM502U)
PRE-CHECK
1. DIAGNOSIS SYSTEM
(a) Description
When troubleshooting OBD II vehicles, the only differ-
ence from the usual troubleshooting procedure is that you
connect to the vehicle the OBD II scan tool complying with
SAE J1978 or TOYOTA hand-held tester, and read off
various data output from the vehicle's ECM.
OBD II regulations require that the vehicle's on-board
computer lights up the Malfunction Indicator Lamp (MIL)
on the instrument panel when the computer detests a
malfunction in the computer itself or in drive system com-
ponents which affect vehicle emissions. In addition to the
MIL lighting up when a malfunction is detected, the appli-
cable Diagnostic Trouble Codes (DTC) prescribed by
SAE J2012 are recorded in the ECM memory.
(See page DI-158)
If the malfunction does not reoccur in 3 trips, the MIL goes
off but the DTC remain recorded in the ECM memory.
To check the DTC, connect the OBD II scan tool or TOYO-
TA hand-held tester to Data Link Connector 3 (DLC3) on
the vehicle. The OBD II scan tool or TOYOTA hand-held
tester also enables you to erase the DTC and check
freezed frame data and various forms of engine data. (For
operating instructions, see the OBD II scan tool's instruc-
tion book.)
DTC include SAE controlled codes and Manufacturer
controlled codes.
SAE controlled codes must be set as prescribed by the
SAE, while Manufacturer controlled codes can be set
freely by the manufacturer within the prescribed limits.
(See DTC chart on page DI-158)
The diagnosis system operates in normal mode during
normal vehicle use. It also has a check mode for techni-
cians to simulate malfunction symptoms and trouble-
shoot. Most DTC use 2 trip detection logic* to prevent er-
roneous detection and ensure thorough malfunction
detection. By switching the ECM to check mode when
troubleshooting, the technician can cause the MIL to light
up for a malfunction that is only detected once or momen-
tarily. (TOYOTA hand-held tester only)
(See page DI-147)
*2 trip detection logic: When a logic malfunction is first de-
tected, the malfunction is temporarily stored in the ECM
memory. If the same malfunction is detected again during
the second drive test, this second detection causes the
MIL to light up.

N09214
DLC3 DI-148
- DIAGNOSTICSENGINE (2JZ-GTE)
376 Author
: Date
:
1997 SUPRA (RM502U)
The 2 trip repeats the same mode a 2nd time. (However,
the IG switch must be turned OFF between the 1st trip and
2nd trip).
Freeze frame data:
Freeze frame data records the engine condition when a
misfire (DTC P0300 - P0306) or fuel trim malfunction
(DTC P0171, P0172), or other malfunction (first malfunc-
tion only), is detected.
Because freeze frame data records the engine conditions
(fuel system, calculator load, engine coolant tempera-
ture, fuel trim, engine speed, vehicle speed, etc.) when
the malfunction is detected, when troubleshooting it is
useful for determining whether the vehicle was running or
stopped, the engine warmed up or not, the air-fuel ratio
lean or rich, etc. at the time of the malfunction.
Priorities for Troubleshooting:
If troubleshooting priorities for multiple DTC are given in
the applicable diagnostic chart, these should be followed.
If no instructions are given troubleshoot DTC according
to the following priorities.
(1) DTC other than fuel trim malfunction (DTC P0171,
P0172), EGR (DTC P0401, P0402), and misfire
(DTC P0300 - 0306).
(2) Fuel trim malfunction (DTC P0171, P0172) and
EGR (DTC P0401, P0402).
(3) Misfire (DTC P0300 - P0306).
(b) Check the DLC3.
The vehicle's ECM uses V.P.W. (Variable Pulse Width) for
communication to comply with SAE J1850. The terminal
arrangement of DLC3 complies with SAE J1962 and
matches the V.P.W. format.
Terminal No.Connection / Voltage or ResistanceCondition
2Bus  Line / Pulse generationDuring transmission
4Chassis Ground / e Body Ground 1 W or lessAlways
5Signal Ground / e Body Ground 1 W or lessAlways
16Battery Positive / e Body Ground 9 - 14 VAlways
HINT:
If your display shows ºUNABLE TO CONNECT TO VEHICLEº
when you have connected the cable of the OBD II scan tool or
TOYOTA hand-held tester to DLC3, turned the ignition switch
ON and operated the scan tool, there is a problem on the ve-
hicle side or tool side.

If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.

If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool's instruction manual.

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)

FI3605
Flashing
ON
OFF
0.13 Seconds DI-150
- DIAGNOSTICSENGINE (2JZ-GTE)
378 Author
: Date
:
1997 SUPRA (RM502U)
TOYOTA hand-held tester only:
Compared to the normal mode, the check mode has an in-
creased sensitivity to detect malfunctions.
Furthermore, the same diagnostic items which are detected in
the normal mode can also be detected in the check mode.
(a) Check the DTC.
(1) Initial conditions.

Battery positive voltage 11 V or more.

Throttle valve fully closed.

Transmission in park or neutral position.

Air conditioning switched OFF.
(2) Turn ignition switch OFF.
(3) Prepare the TOYOTA hand-held tester.
(4) Connect the TOYOTA hand-held tester to DLC3 at
the lower left of the instrument panel.
(5) Turn the ignition switch ON and switch the TOYOTA
hand-held tester ON.
(6) Switch the TOYOTA hand-held tester normal mode
to check mode. (Check that the MIL flashes.)
(7) Start the engine. (The MIL goes out after the engine
start.)
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTC, etc.
(9) After simulating the malfunction conditions, use the
TOYOTA hand-held tester diagnosis selector to
check the DTC and freezed frame data, etc.
HINT:
Take care not to turn the ignition switch OFF. Turning the ignition
switch OFF switches the diagnosis system from check mode to
normal mode, so all DTC, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.
(b) Clear the DTC.
The following actions will erase the DTC and freezed frame
data.
(1) Operating the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand-held tester to erase the
codes. (See the OBD II scan tool's instruction book
for operating instructions.)
(2) Disconnecting the battery terminals or EFI fuse.
NOTICE:
If the TOYOTA hand-held tester switches the ECM from
normal mode to check mode or vice-versa, or if the ignition
switch is turned from ON to ACC or OFF during check
mode, the DTC and freezed frame data will be erased.

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-151
379 Author
: Date
:
1997 SUPRA (RM502U)
4. FAIL-SAFE CHART
If any of the following codes is recorded, the ECM enters fail-safe mode.
DTC No.Fail-Safe OperationFail-safe Deactivation Conditions
P0100Fuel cutReturned to normal condition
P0110Intake air temp. is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temp. is fixed at 80°C (176°F)Returned to normal condition
P0120VTA is fixed at 0°
The following condition must be repeated at least 2 times
consecutively
When closed throttle position switch is ON:
0.25 V  VTA1 0.95 V
P0135
P0141The heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P0500High RPM fuel cut is prohibited
IAC control prohibitedReturned to normal condition
P1100HAC is fixed at 760 mm HgReturned to normal condition
P1300Fuel cutReturned to normal condition
P1400Sub throttle valve is fixed at almost fully-open position
The following condition must be repeated at least 2 times
consecutively.
When closed subthrottle position switch is ON:
0.25 V  VTA2 0.95 V
P1405Waste gate valve is fixed at open positionReturned to normal condition
P1512Fuel cutPressure intake manifold  1400 mm Hg´abs
P1605Max. timing retardationReturned to normal condition
P1630Does not into the manual patternReturned to normal condition
5. CHECK FOR INTERMITTENT PROBLEMS
TOYOTA hand-held tester only:
By putting the vehicle's ECM in check mode, 1 trip detection logic is possible instead of 2 trip detection logic
and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
(1) Clear DTC (See page DI-147)
(2) Set check mode (See page DI-147)
(3) Perform a simulation test (See page IN-18)
(4) Connector connection and terminal inspection (See page IN-28)
(5) Visual check and contact pressure check (See page IN-28)
(6) Connector handling (See page IN-28)

P19604
A/C Amplifier
5 V
6
A14L-R31
II1L-R34
AAC1ECM
E1
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-313
541 Author
: Date
:
1997 SUPRA (RM502U)
A/C Cut Control Circuit
CIRCUIT DESCRIPTION
This circuit cuts air conditioning operation during vehicle acceleration in order to increase acceleration per-
formance. During acceleration with the vehicle speed at 25 km/h (16 mph) or less, engine speed at 1,200
rpm or less and throttle valve opening angle at 60° or more, the A/C magnet switch is turned OFF for several
seconds.
WIRING DIAGRAM
INSPECTION PROCEDURE
TOYOTA hand-held tester
1 Connect the TOYOTA hand-held tester and check operation of air conditioning
cut control.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push TOYOTA hand-held tester main switch ON.
(c) Start the engine and air conditioning switch ON.
HINT:
A/C magnetic clutch is turned ON.
(d) Select the ACTIVE TEST mode on the TOYOTA hand-held tester.
CHECK:
Check operation of A/C magnetic clutch cut when air conditioning cut control is operated by the TOYOTA
hand-held tester.
OK:
A/C magnetic clutch is turned OFF.
DI4TW-01

F03406F03406
Throttle Control ECU SNOW
Indicator
Light J/B No.1
SNOW Mode Switch
(TRAC Control Switch)SIND
SNOW GAUGEP-G
P-G
R-B W-B
W-B
W-B
YT1611
T1614 IF19
C125
C109
1E12
IE IG8 6
F03407
6
8
SNOW Mode Switch
(TRAC Control Switch)
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-551
779 Author
: Date
:
1997 SUPRA (RM502U)
SNOW Indicator Light, SNOW Mode Switch Circuit
CIRCUIT DESCRIPTION
When you push the SNOW mode switch, TRAC control becomes SNOW mode operation and the SNOW
indicator light on, and when you push the TRAC OFF switch, TRAC control will be released to normal mode
operation and the SNOW indicator light goes off.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check SNOW mode switch.
PREPARATION:
(a) Remove SNOW mode switch (TRAC control switch).
(b) Disconnect TRAC control switch connector.
CHECK:
Measure resistance between terminals 6 and 8 of TRAC control
switch when SNOW mode switch on and off.
OK:
TRAC control switchResistance
SNOW mode switch pushed inContinuity
TRAC OFF switch pushed in1 MW or higher
NG Replace TRAC control switch.
OK
DI4WB-01

5
B
I :Junction Block (The number in the circle is the
J/B No. and the connector code is shown beside
it). Junction Blocks are shaded to clearly
separate them from other parts .
A :System Title
B :Indicates a Relay Block. No shading is used and only the
Relay Block No. is shown to distinguish it from the J/B.
Example: 1 Indicates Relay Block No. 1.
C :Indicates the connector to be connected to a
part (the numeral indicates the pin No.)
Explanation of pin use.J :Indicates the wiring color.
Wire colors are indicated by an alphabetical code.
B = Black
BR = Brown
G = Green
GR = GrayL = Black
LG = Light Green
O = Orange
P = PinkR = Red
V = Violet
W = White
Y = Yellow
The first letter indicates the basic wire color and the second
letter indicates the color of the stripe.
D :Connector Color Connectors not indicated are milky
white in color:
E :( ) is used to indicate different wiring and connector, etc.
when the vehicle model, engine type, or specification is
different.
F :Indicates related system.
G :Indicates the wiring harness and wiring harness
connector. The wiring harness with male terminal is
shown with arrows ( ).
Example: L - Y
K :Indicates a wiring Splice Point (Codes are Eº for
the Engine Room, Iº for the Instrument Panel,
and Bº for the Body).
Example:
The Location of Splice Point I 5 is indicated by the shaded
section.
L :Page No.
M :Indicates a shielded cable.
Example:N :Indicates a ground point.
The first letter of the code for each ground point(s) indicates
the component's location, e.g. Eº for the Engine
Compartment, Iº for the Instrument Panel and Surrounding
area, and Bº for the Body and Surrounding area.
The first letter of the code for each wiring harness and wiring
harness connector(s) indicates thecomponent's location, e.g,
Eº for the Engine Compartment, Iº for the Instrument Panel
and Surrounding area, and Bº for the Body and Surrounding
area.
When more than one code has the first and second letters in
common, followed by numbers (e.g, IH1, IH2), this indicates
the same type of wiring harness and wiring harness connector.
P :When 2 parts both use one connector in common, the parts
connector name used in the wire routing section is shown in
square brackets [ ]. O :Indicates the pin number of the connector.
The numbering system is different for female and male
connectors.
H :Represents a part (all parts are shown in sky
blue). The code is the same as the code used in
parts position.
3B indicates
that it is inside
Junction Block
No. 3. v
v The pins shown are only for the highest grade, or only
include those in the specification.
lower rightlower left
(blue) (yellow)