TOYOTA SUPRA 1997 Service Repair Manual

Q04361 FI6643A03136
T/M4-Pulse 4-Pulse
ECM
Combination
Meter No.1 Vehicle
Speed MeterTransmission
Output Shaft
Driven Gear
No.1 Vehicle Speed Sensor
S01080
GAUGE Fuse
23
II1
YY
Y
1
1
2No.1 Vehicle
Speed Sensor
Speed Meter3
L-R
II12
L-R5
Odometer and
Trip Meter
Telltale Light RH6
P11
II1P2
ASP1ECM
5V
E1 DI-238
- DIAGNOSTICSENGINE (2JZ-GTE)
466 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
The No.1 vehicle speed senor outputs a 4-pulse signal for every revolution of the rotor shaft, which is rotated
by the transmission output shaft via the driven gear. After this signal is converted into a more precise rectan-
gular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted to the
ECM. The ECM determines the vehicle speed based on the frequency of these pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM under the following
conditions:
(2 trip detection logic)
(a) Park/neutral position switch is OFF
(b) Vehicle is being driven
Open or short in vehicle speed sensor circuit

Vehicle speed sensor

Combination meter

ECM
WIRING DIAGRAM
DI4T7-01

A00714
ONCheck Harness A
ECM
A2 SP1(+)
AT7809
4.5 - 5.5 V
0Turn the wheel
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-239
467 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The No.1 vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit (See page BE-43).
OK
2 Check voltage between terminal SP1 of ECM connector and body ground.
PREPARATION:
(a) Shift the shift lever to neutral position.
(b) Jack up one of rear wheels.
(c) Connect Check Harness A (See page DI-164).
(d) Disconnect power steering ECU connector and cruise
control ECU connector.
(e) Turn ignition switch ON.
CHECK:
Measure voltage between terminal SP1 of ECM connector and
body ground when rear wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector be-
tween combination meter and ECM.
OK
Check and replace ECM (See page IN-28).

FI6973
Throttle Body
Chamber
From
Air
Flow
Meter
To
Cylinder Head
Valve ShaftRotorCoilsValveThrottle
Valve
Air Intake
S03465
Battery
B
W-B
EB
EFI No.1
2A2
R/B
No.2
B-W
22 2
2
5
1
3 2B-Y B-R2
B-R
EA2
EA18
GR24
35
33
34
32A
B
B
B
B
B-R
5
2B1
B2S1
S3
S2
S44
6
1 3
IAC ValveV-Y
G-O
G-W
R-GE01 ISC1
M-REL
B+ ECM
ISC3
ISC2
ISC4
1
EFI Main Relay
R/B
No.2 DI-240
- DIAGNOSTICSENGINE (2JZ-GTE)
468 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The step motor type IAC valve is located in front of the intake
air chamber. Intake air bypassing the throttle valve is directed
to the IAC valve through a passage. A step motor is built into
the IAC valve. It consists of 4 coils, a magnetic rotor, valve shaft
and valve.
When current flows to the coils due to signals from the ECM, the
rotor turns and moves the valve shaft forward or backward,
changing the clearance between the valve and the valve seat.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
There are 125 possible positions to which the valve can be
opened.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)

IAC valve is stuck or closed

Open or short in IAC valve circuit

Open or short in A/C signal circuit

Air intake (hose loose)
WIRING DIAGRAM
DI4T8-01

A00202
A/C Switch OFF " ON
(IAC Valve Open)
A/C Switch ON " OFF
(IAC Valve Close)
20 V/Division
20 V/Division ISC1
ISC2
ISC3
ISC4
ISC1
ISC2
ISC3
ISC4
10 msec./Division
10 msec./Division
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-241
469 Author
: Date
:
1997 SUPRA (RM502U)
Reference INSPECTION USING OSCILLOSCOPE

With engine idling measure waveforms between termi-
nals ISC1, ISC2, ISC3, ISC4 and E01 of ECM when A/C
switch ON or OFF.
HINT:
The correct waveforms are as shown.
INSPECTION PROCEDURE
1 Check air induction system (See page SF-1).
NG Repair or replace.
OK

A00715
ON
Check Harness A
B35, 34, 33, 32
ISC1(+)
ISC2(+)ISC3(+)
ISC4(+)
DI-242
- DIAGNOSTICSENGINE (2JZ-GTE)
470 Author
: Date
:
1997 SUPRA (RM502U)
2 Check voltage between terminals ISC1, ISC2, ISC3, ISC4 of ECM connector and
body ground.
PREPARATION:
(a) Connect Check Harness A to the connectors on the wire
harness side (See page DI-164).
HINT:
The other side of Check Harness A is not connected to the ECM
terminals.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals ISC1, ISC2, ISC3, ISC4 of
ECM connector and body ground.
OK:
Voltage: 9 - 14 V
OK Go to step 4.
NG
3 Check IAC valve (See page SF-52).
NG Replace IAC valve.
OK
Check for open and short in harness and connector between EFI main relay (Marking: EFI MAIN)
and IAC valve, IAC valve and ECM (See page IN-28).
4 Check operation of the IAC valve (See page SF-52).
NG Repair or replace IAC valve.
OK
Check and replace ECM (See page IN-28).

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-243
471 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0510 Closed Throttle Position Switch Malfunction
CIRCUIT DESCRIPTION
Refer to ºThrottle/Pedal Position Sensor/Switch ºAº Circuit Malfunctionº on page DI-184.
DTC No.DTC Detecting ConditionTrouble Area
P0510
The closed throttle position switch does not turn ON or OFF
even once when the vehicle is driven
(2 trip detection logic)
Open or short in closed throttle position switch circuit

Closed throttle position switch

ECM
HINT:
After confirming DTC P0510 use the TOYOTA hand-held tester to confirm the closed throttle position switch
signal from ºCURRENT DATAº.
Throttle ValveClosed throttle position switch signalMalfunction
Fully ClosedOFFOpen Circuit
Fully OpenONShort Circuit
WIRING DIAGRAM
Refer to page DI-184 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
HINT:
If DTC P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
TOYOTA hand-held tester
1 Connect the TOYOTA hand-held tester and read CTP switch signal.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push the TOYOTA hand-held tester main switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand-held tester.
RESULT:
Throttle ValveClosed throttle position switch signalMalfunction
Fully ClosedOFFOpen Circuit: Go to step 2.
Fully OpenONOpen Circuit: Go to step 4.
DI4T9-01

BE6653
FI7058A00486
ON
Throttle Position
SensorECM
4
3
2
141
43
64
65B
B
B
B
VCC5V
VTA1
B+
IDL1
E2
A00716
ON
Throttle Position
Sensor
ECM
4
3
2
141
43
64
65
B
5V
IDL1
E2B B
VTA1
B+
BVCC
Check Harness A
ECM
B65, 64
IDL1 E2
DI-244
- DIAGNOSTICSENGINE (2JZ-GTE)
472 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Disconnect the throttle position sensor connector.
(c) Connect sensor wire harness terminals between termi-
nals 1 and 2.
(d) Turn ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: ON
OK Confirm good connection at sensor.
If OK, replace throttle position sensor.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Connect between terminals IDL and E2 of ECM connec-
tor.
HINT:
Throttle position sensor connector is disconnected.
Before checking, do a visual check and contact pressure check
for the connector (See page IN-28).
(c) Turn ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: ON
OK Open in harness between ECM and throttle
position sensor, repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM.

BE6653A00499A00488
ON
Throttle Position
SensorECM
4
3
2
141
43
64
65
B
5V
IDL1
E2B B
VTA1 B+
BVCC
A00717
ON
Throttle Position
Sensor
ECM
4
3
2
141
43
64
65
B
5V
IDL1
E2
BB
VTA1 B+
BVCC
ECM
B Connector
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-245
473 Author
: Date
:
1997 SUPRA (RM502U)
4 Check for short in harness or ECM.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Disconnect the throttle position sensor connector.
(c) Turn ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: OFF
OK Confirm good connection at sensor.
If OK, replace throttle position sensor.
NG
5 Check for short in harness or ECM.
PREPARATION:
(a) DIsconnect the B connector from ECM
(See page DI-164).
HINT:
Throttle position sensor connector is disconnected.
(b) Turn ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: OFF
OK Short in harness between ECM and throttle
position sensor, repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM.

A00492
ON
Throttle Position
SensorECM
4
3
2(+)
1(-)41
43
64
65
B
5V
IDL1
E2
B B
VTA1
B+
BVCC
DI-246
- DIAGNOSTICSENGINE (2JZ-GTE)
474 Author
: Date
:
1997 SUPRA (RM502U)
OBDII scan tool (excluding TOYOTA hand-held tester)
1 Check for open and short in harness or ECM.
PREPARATION:
(a) Disconnect the throttle position sensor connector.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals 1 and 2 of throttle position
sensor connector.
OK:
Voltage: 9 - 14 V
OK Confirm good connection at sensor.
If OK, replace throttle position sensor.
NG
2 Check for open and short in harness and connector between throttle position
sensor and ECM (See page IN-28).
NG Open or short in harness between ECM and
throttle position sensor.
OK
Confirm connection at ECM.
If OK, replace ECM.

S03241S03242
A06719
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-215
443 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
The camshaft position sensors (G1 and G2 signals) consist of a signal plate and a pick up coil.
The G1, G2 signal plates each have one tooth on the outer circumference and are mounted on the intake
side of the cylinder head.
When the camshaft rotates, the protrusion on the signal plate and the air gap on the pick up coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pick up coil.
The ECM detects the standard crankshaft angle based on the G1, G2 signals, detects the actual crankshaft
angle and engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM with engine speed
600 rpm or more
Open or short in camshaft position sensor circuit

Camshaft position sensor
StarterP0340
No crankshaft position sensor signal to ECM during cranking

Starter

ECM
WIRING DIAGRAM
Refer to page DI-212 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensors.
PREPARATION:
Disconnect camshaft position sensor connector.
CHECK:
Measure resistance of camshaft position sensors.
OK:
Resistance
Cold835 - 1,400 W
Hot1,060 - 1,645 W
ºColdº is from - 10°C (14°F) to 50°C (122°F) and ºHotº is from
50°C (122°F) to 100°C (212°F).
DI4T2-01