Page 651 of 1807

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 drivenOpen or short in vehicle speed sensor circuit
Vehicle speed sensor
Combination meter
ECM
WIRING DIAGRAM
DI4T7-01
Page 653 of 1807

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
Page 656 of 1807

- 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
Page 660 of 1807

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 moreOpen 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
Page 663 of 1807

S05428
Battery
B
W-B
EFI No.1
EB
R/B
No.2
2A12
B-D
R/B
No.2
2
2 2 2
51
32
EFI No.2 Relay
B-R L-O
E1 L-O
B-R
B-R 5EA2
BP1
BI
2
W-B
W-B
Fuel
Pump
5 4
L
6BP1
5L-R
FP4 Fuel Pump ECU
B+
B+
E
1DI FPCVSV for
Fuel Pressure
12
W-L
IB1IC2
73
22
21
B
A
A
V-WV-W
V-W
GG
G 1211
124IC2IJ1
IJ1
IC2
DI FPC5VEO1 FPUECM
5
10 DI-248
- DIAGNOSTICSENGINE (2JZ-GTE)
476 Author: Date:
1997 SUPRA (RM502U)
DTC P1200 Fuel Pump Relay/ECU Circuit Malfunction
CIRCUIT DESCRIPTION
The fuel pump speed is controlled at 2 steps (high speed, low speed) by the condition of the engine (starting,
light load, heavy load), when the engine starts (STA ON), the ECM sends a Hi signal (about 5 V) to the fuel
pump ECU (FPC terminal).
The fuel pump ECU then outputs Hi voltage (battery positive voltage) to the fuel pump so that the fuel pump
operates at high speed.
After the engine starts, during idling or light loads, the ECM outputs a Low signal (about 2.5 V) to the fuel
pump ECU, the fuel pump ECU outputs Low voltage (about 9 V) to the fuel pump and causes the fuel pump
to operate at low speed.
If the intake air volume increases (high engine load), the ECM sends a Hi signal to the fuel pump ECU and
causes the fuel pump to operate at high speed.
DTC No.DTC Detecting ConditionTrouble Area
Open or short in fuel pump circuit for 1 sec. or more with en-
gine speed 1,000 rpm or less
(2 trip detection logic)
Open or short in fuelpumpECU circuit
P1200
Open in input circuit of fuel pump ECU (FPC) with engine
speed 1,000 rpm or less
(2 trip detection logic)
Open or short in fuel pump ECU circuit
Fuel pump ECU
ECM power source circuit
Fuel pump
Open or short in diagnostic signal line (DI) of fuel pump ECU
with engine speed 1,000 rpm or less
(2 trip detection logic)
Fuel um
ECM
WIRING DIAGRAM
DI4TB-01
Page 667 of 1807

S03235
Battery
B
R/B
No.22
2A
AM2
W-R W-R
IB147 6
Igniter
Switch
B-O
IJ11B-OB-OB-O B-O B-O
B-O
B-O
B-O
B-O
B-O
B-O
Spark Plug
Ignition Coil No.1
L-YG
Y
Y-B
Y-G
Y-R No.2
No.3
No.4
No.5
No.6 112
1
1
1
1
12
2
2
2
2
2
1
Noise Filter
BRECM
BR
EC
I24Igniter Tr
2
I22
6
5
4
10
11
12
I3 B
B
B
B
B
B
B
1
2
3
9
8
7
357
56
55
54
53
52
58
IGF5V IGT6 IGT5 IGT4IGT3 IGT2 IGT1
Tr1
5V
I3
I3
I3
I3
I3
I2 I3I3 I3 I3 I3I3
R-W
W-R
LG
B-R
L
R
R-Y DI-252
- DIAGNOSTICSENGINE (2JZ-GTE)
480 Author: Date:
1997 SUPRA (RM502U)
DTC P1300 Igniter Circuit Malfunction
CIRCUIT DESCRIPTION
The ECM determines the ignition timing, turns on Tr1 at a predetermined angle (°CA) before the desired
ignition timing and outputs an ignition signal (IGT) º1º to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines the time
the control circuit starts primary current flow to the ignition coil based on the engine rpm and ignition timing
one revolution ago, that is, the time the Tr2 turns on.
When it reaches the ignition timing, the ECM turns Tr1 off and outputs the IGT signal º0º.
This turns Tr2 off, interrupting the primary current flow and generating a high voltage in the secondary coil
which causes the spark plug to spark. Also, by the counter electromotive force generated when the primary
current is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECM.
The ECM stops fuel injection as a fail safe function when the IGF signal is not input to the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P1300No IGF signal to ECM for 6 consecutive IGT signals during
engine runningOpen or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM
WIRING DIAGRAM
DI4TC-01
Page 672 of 1807
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-257
485 Author: Date:
1997 SUPRA (RM502U)
DTC P1335 Crankshaft Position Sensor Circuit
Malfunction (during engine running)
CIRCUIT DESCRIPTION
Refer to ºCrankshaft Position Sensor ºAº Circuit Malfunctionº on page DI-212.
DTC No.DTC Detecting ConditionTrouble Area
P1335No crankshaft position sensor signal (NE signal) to ECM with
engine speed 1,000 rpm or more
Open or short in crankshaft position sensor circuit for NE
signal
Crankshaft position sensor for NE signal
Starter
ECM
See DTC P0335 for the WIRING DIAGRAM and INSPECTION PROCEDURE.
DI4TD-01
Page 673 of 1807
FI6571
Sub Throttle Position
SensorECM
5V
B+ VCC
VTA2
IDL2
E2
DI-258
- DIAGNOSTICSENGINE (2JZ-GTE)
486 Author: Date:
1997 SUPRA (RM502U)
DTC P1400 Sub Throttle Position Sensor Malfunction
CIRCUIT DESCRIPTION
The sub throttle position sensor is built and operates in the
same way as the main throttle position sensor. This sensor is
used for traction control. The sub throttle valve is opened and
closed by the sub throttle actuator according to signals from the
throttle control ECU to control the engine output.
DTC No.DTC Detecting ConditionTrouble Area
P1400
Condition (a) or (b) continues:
(a) VTA 2 < 0.25 V, and closed sub throttle position switch is
OFF
(b) VTA 2 > 4.9 VOpen or short in sub throttle position sensor circuit
Sub throttle position sensor
ECM
WIRING DIAGRAM
Refer to page DI-184 for the WIRING DIAGRAM.
DI4TE-01