1997 TOYOTA SUPRA throttle body sensor

IN-36
- INTRODUCTIONTERMS
36 Author
: Date
:
1997 SUPRA (RM502U) HO2S
Heated Oxygen SensorHeated Oxygen Sensor (HO2S)
IACIdle Air ControlIdle Speed Control (ISC)
IATIntake Air TemperatureIntake or Inlet Air Temperature
ICMIgnition Control Module-
IFIIndirect Fuel InjectionIndirect Injection
IFSInertia Fuel-Shutoff-
ISCIdle Speed Control-
KSKnock SensorKnock Sensor
MAFMass Air FlowAir Flow Meter
MAPManifold Absolute PressureManifold Pressure
Intake Vacuum
MCMixture Control
Electric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDPManifold Differential Pressure-
MFIMultiport Fuel InjectionElectronic Fuel Injection (EFI)
MILMalfunction Indicator LampCheck Engine Light
MSTManifold Surface Temperature-
MVZManifold Vacuum Zone-
NVRAMNon-V olatile Random Access Memory-
O2SOxygen SensorOxygen Sensor, O2 Sensor (O2S)
OBDOn-Board DiagnosticOn-Board Diagnostic (OBD)
OCOxidation Catalytic ConverterOxidation Catalyst Converter (OC), CCo
OPOpen LoopOpen Loop
PAIRPulsed Secondary Air InjectionAir Suction (AS)
PCMPowertrain Control Module-
PNPPark/Neutral Position-
PROMProgrammable Read Only Memory-
PSPPower Steering Pressure-
PTOXPeriodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAMRandom Access MemoryRandom Access Memory (RAM)
RMRelay Module-
ROMRead Only MemoryRead Only Memory (ROM)
RPMEngine SpeedEngine Speed
SCSuperchargerSupercharger
SCBSupercharger Bypass-
SFISequential Multiport Fuel InjectionElectronic Fuel Injection (EFI), Sequential Injection
SPLSmoke Puff Limiter-
SRIService Reminder Indicator-
SRTSystem Readiness Test-
STScan Tool-
TBThrottle BodyThrottle Body
TBIThrottle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TCTurbochargerTurbocharger
TCCTorque Converter ClutchTorque Converter

FI6480
Throttle Position
SensorECM
VCC
VTA1
IDL1
E25V
B+ DI-184
- DIAGNOSTICSENGINE (2JZ-GTE)
412 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0120 Throttle/Pedal Position Sensor/Switch ºAº
Circuit Malfunction
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle. When the throttle valve
is fully closed, the IDL1 contacts in the throttle position sensor
are on, so the voltage at the terminal IDL1 of the ECM becomes
0 V. At this time, a voltage of approximately 0.7 V is applied to
terminal VTA1 of the ECM. When the throttle valve is opened,
the IDL1 contacts go off and thus the power source voltage of
approximately 12 V in the ECM is applied to the terminal IDL1
of the ECM. The voltage applied to the terminal VTA1 of the
ECM increases in proportion to the opening angle of the throttle
valve and becomes approximately 3.2 - 4.9 V when the throttle
valve is fully opened. The ECM judges the vehicle driving condi-
tions from these signals input from terminals VTA1 and IDL1,
and uses them as one of the conditions for deciding the air-fuel
ratio correction, power increases correction and fuel-cut con-
trol etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) conditions:
(a) VTA < 0.25 V, and closed throttle position switch is OFF
(b) VTA > 4.9 V
Open or short in throttle position sensor circuit

Throttle position sensor

ECM
HINT:

If there is open circuit in IDL line, DTC P0120 does not indicate.

After confirming DTC P0120 use the OBD II scan tool or TOYOTA hand-held tester to confirm the
throttle valve opening percentage and closed throttle position switch condition.
Throttle valve opening position expressed as percentageTblAThrottle valve fully closedThrottle valve fully openTrouble Area
0 %0 %VC line open
VTA1 line open or short
Approx. 100 %Approx. 100 %E2 line open
DI4SR-01

FI7052
A00694
ON
1(+)
DI-186
- DIAGNOSTICSENGINE (2JZ-GTE)
414 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
If DTC P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
1 Connect the OBD II scan tool or TOYOTA hand-held tester and read the throttle
valve opening percentage.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC 3.
(b) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand-held tester main switch ON.
CHECK:
Read the throttle valve opening percentage.
OK:
Throttle valveThrottle valve opening position ex-
pressed as percentage
Fully openApprox. 70 %
Fully closedApprox. 10 %
OK Check for intermittent problems
(See page DI-147).
NG
2 Check voltage between terminal 1 of wire harness side connector and body
ground.
PREPARATION:
(a) Disconnect the throttle position sensor connector.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal 1 of wire harness side con-
nector and body ground.
OK:
Voltage: 4.5 - 5.5 V
NG Go to step 5.
OK

DI4VS-01
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-503
731 Author
: Date
:
1997 SUPRA (RM502U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Using SST 09843-18020, connect the terminals Tc and E
1.
If a malfunction code is displayed during the DTC check, check the circuit listed for that code. For details
of each code, turn to the page referred to under the ºSee pageº for the respective ºDTC No.º in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble Area
11
(DI-509)Throttle control relay circuit open

Throttle control relay

TRAC fuse

Wire harness and connector (throttle control relay circuit)

Throttle control ECU
12
(DI-509)Throttle control relay circuit short

Throttle control relay

Wire harness and connector (throttle control relay circuit)

Throttle control ECU
21
(DI-513)Sub-throttle valve motor circuit open or short

Sub-throttle valve motor

Wire harness and connector (sub-throttle valve motor and
E01 circuit)

Throttle control ECU
22
(DI-513)Sub-throttle valve motor malfunction

Sub-throttle valve motor

Sub-throttle valve

Sub-throttle position sensor

Wire harness and connector (E1 circuit)

Throttle control ECU
23
(DI-516)Throttle body malfunction

Sub-throttle valve

Sub-throttle position sensor

Throttle control ECU
24
(DI-519)Sub-throttle position sensor leakage/sub-throttle valve stuck

Sub-throttle valve

Sub-throttle position sensor

Wire harness and connector (E1 circuit)

Throttle control ECU
31
(DI-522)Throttle position sensor signal malfunction

Throttle position sensor

Wire harness and connector (throttle position senor and E1
circuit)

Throttle control ECU
32
(DI-526)Sub-throttle position sensor signal malfunction

Sub-throttle position sensor

Sub-throttle valve motor

Sub-throttle valve

Wire harness and connector (sub-throttle position senor and
E1 circuit)

Throttle control ECU
41
(DI-530)Engine revolution signal open or short

Wire harness and connector (NE circuit)

ECM

Throttle control ECU
42
(DI-532)ECM malfunction

Wire harness and connector (EFIF circuit)

ECM

Throttle control ECU
43
(DI-534)ECM communication circuit malfunction

Wire harness and connector (EFI+ and EFI- circuit)

ECM

Throttle control ECU
51
(DI-535)Power source voltage down
(sub-throttle valve in a bad condition)
Wire harness and connector (+B and E01 circuit)

Throttle control ECU

- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-515
743 Author
: Date
:
1997 SUPRA (RM502U)
3 Check for open and short in harness and connector between terminal IDL2 of
throttle control ECU and sub-throttle position sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace throttle control ECU.
4 Check sub-throttle position sensor (See page DI-243).
NG Adjust or replace sub-throttle position sensor
(See page SF-44).
OK
5 Check for open and short in harness and connector between terminals E01, E1
of throttle control ECU and body ground (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace throttle control ECU.

F03376
ECM
VTO2
IDL2
Sub-throttle
Position Sensor 39
E10
E963
GR-R G-O
T1519
GR-R GR-R 3
T15
26
T15BR 12V
VTA2
12V
12V
GE01
E01B BA A
12V
12V 12
T15
T15
25
T15
T15
23
T15
13
T15 W-B
2
ED EC
IDL2
E1 11
24
Throttle Control ECU
(SHIELDED)
L
Y
R
B Sub- throttle
Valve Motor
6
4
3
1 DI-516
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
744 Author
: Date
:
1997 SUPRA (RM502U)
DTC 23 Throttle Body Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
23In case the sub-throttle valve is fully open or full close angle
become smaller.
Sub-throttle valve

Sub-throttle position senor

Throttle control ECU
WIRING DIAGRAM
DI4VY-01

F03378BE6653F03379F03380
ON
IDL2
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
DI-517
745 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check voltage between terminal IDL2 of throttle control ECU and body ground.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Remove intake air duct.
(c) Disconnect sub-throttle valve motor connector.
(d) Turn ignition switch ON.
CHECK:
Measure voltage between terminal IDL2 of throttle control ECU
and body ground, when the sub-throttle valve is fully closed
and fully open.
OK:
Sub-throttle valve positionVoltage
Fully closed0 - 3 V
Fully open9 - 14 V
OK Go to step 3.
NG
2 Check for open and short in harness and connector between terminal IDL2 of
throttle control ECU and sub-throttle position sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace throttle control ECU.

F03378BE6653F03382F03383
ON
(-)
VTA2 (+)
DI-520
- DIAGNOSTICSABS & TRACTION CONTROL SYSTEM
748 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check voltage between terminal VTA2 of throttle control ECU and body ground.
PREPARATION:
(a) Remove throttle control ECU with connectors still con-
nected.
(b) Remove intake air duct.
(c) Disconnect sub-throttle valve motor connector.
(d) Turn ignition switch ON.
CHECK:
Measure voltage between terminal VTA2 of throttle control ECU
and body ground, when the sub-throttle valve is fully closed
and fully open.
OK:
Sub-throttle valve positionVoltage
Fully closed0.3 - 0.8 V
Fully open3.2 - 4.9 V
OK Go to step 3.
NG
2 Check for open and short in harness and connector between terminal VTA2 of
throttle control ECU and terminal VTO2 of ECM (See page IN-28).
NG Repair or replace harness or connector.
OK
Check and replace throttle control ECU.
3 Check sub-throttle position sensor (See page DI-243).
NG Adjust or replace sub-throttle position sensor
(See page SF-44).
OK