1995 TOYOTA SUPRA ignition

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Check and replace ECM.
Check voltage between terminal A/C of ECM and body ground.
Check voltage between terminal MGC of A/C amplifier connector and
body ground.
Magnetic ClutchVoltage
ON
OFF
Below 1 V
4 ± 6 V
1. Remove A/C amplifier with connectors still con
nected.
2. Start the engine.
Check voltage between terminal A/C IN of A/C amplifi-
er connector and body ground when magnetic clutch is
on and off by A/C switch.
1. Remove the ECM with connectors still con
nected.
2. Turn ignition switch on.
Magnetic ClutchVoltage
ON
OFF
Below 1 V
10 ± 14 V
Check and replace A/C amplifier.
Repair or replace harness or connector.
Check for open and short in harness and connector between A/C am-
plifier and ECM (See page IN±30).
1. Push the A/C switch on.
2. Measure voltage between terminal A/C of the
ECM connector and body ground.
AC±64± AIR CONDITIONING SYSTEMTROUBLESHOOTING

Remove magnetic clutch relay from R/B No. 2.
Check continuity between each pair of terminals
shown below of magnetic clutch relay.
Terminals 1 and 2
Terminals 3 and 5
Terminals 3 and 5
No continuity
Continuity
Replace magnetic relay.
Check and replace the ECM.
Repair or replace harness or connector.
A/C SwitchVoltage
ON
OFF
Check for open and short in harness and connector between the ECM and
battery (See page IN±30).
Approx. 1.3. V
Approx. 75

Battery positive voltage
Check magnetic clutch relay.
Check voltage between terminal ACMG of ECM and body ground.
1. Apply battery positive voltage between terminals
1 and 2.
2. Check continuity between terminals 3 and 5.
1. Remove the ECM with connectors still con
nected.
2. Turn ignition switch on.
1. Turn fan speed control dial (Lo, Med or Hi).
2. Measure voltage between terminal ACMG of the
ECM connector and body ground.
Proceed to next circuit inspection shown on matrix
chart (See page AC±26).
~ 1.3 V
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±65

INTRODUCTIONGLOSSARY OF SAE AND TOYOTA TERMS -
IN-7
GLOSSARY OF SAE AND TOYOTA TERMS
This glossary lists all SAE-J1930 terms and abbreviations used in this manual in compliance with SAE
recommendations, as well as their Toyota equivalents.
SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )--ABBREVIATIONS
A/CAir ConditioningAir Conditioner
ACLAir CleanerAir Cleaner
AIRSecondary Air InjectionAir Injection (AI)
APAccelerator Pedal-
B+Battery Positive Voltage+B, Battery Voltage
BAROBarometric Pressure-
CACCharge Air CoolerIntercooler
CARBCarburetorCarburetor
CFIContinuous Fuel Injection-
CKPCrankshaft PositionCrank Angle
CLClosed LoopClosed Loop
CMPCamshaft PositionCam Angle
CPPClutch Pedal Position-
CTOXContinuous Trap Oxidizer-
CTPClosed Throttle Position-
DFIDirect Fuel Injection (Diesel)Direct Injection (DI)
DIDistributor Ignition-
DLC1
DLC2
DLC3Data Link Connector 1
Data Link Connector 2
Data Link Connector 31: Check Connector
2: Toyota Diagnosis Communication Link (TDCL)
3: OBD II Diagnostic Connector
DTCDiagnostic Trouble CodeDiagnostic Code
DTMDiagnostic Test Mode-
ECLEngine Control Level-
ECMEngine Control ModuleEngine ECU (Electronic Control Unit)
ECTEngine Coolant TemperatureCoolant Temperature, Water Temperature (THW)
EEPROMElectrically Erasable Programmable Read Only
MemoryElectrically Erasable Programmable Read Only Memory
(EEPROM),
Erasable Programmable Read Only Memory(EPROM)
EFEEarly Fuel EvaporationCold Mixture Heater (CMH), Heat Control Valve (HCV)
EGRExhaust Gas RecirculationExhaust Gas Recirculation (EGR)
EIElectronic IgnitionToyota Distributorless Ignition (TDI)
EMEngine ModificationEngine Modification (EM)
EPROMErasable Programmable Read Only MemoryProgrammable Read Only Memory (PROM)
EVAPEvaporative EmissionEvaporative Emission Control (EVAP)
FCFan Control-
FEEPROMFlash Electrically Erasable Programmable
Read Only Memory-
FEPROMFlash Erasable Programmable Read Only Memory-
FFFlexible Fuel-
FPFuel PumpFuel Pump
GENGeneratorAlternator
GNDGroundGround (GND)
HO2SHeated Oxygen SensorHeated Oxygen Sensor (HO2S)
IN016-02

INTRODUCTIONGLOSSARY OF SAE AND TOYOTA TERMS -
IN-8
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
TCMTransmission Control ModuleTransmission ECU (Electronic Control Unit)
TPThrottle PositionThrottle Position
TRTransmission Range-

DIAGNOSIS SYSTEM
The Electronically Controlled Transmission has built±in self±
diagnostic functions. If a malfunction occurs in the system,
the ECM stores the diagnostic trouble code in memory and
the O/D OFF (Overdrive OFF) indicator light blinks to inform
the driver. The diagnostic trouble code stored in memory can
be read out by the following procedure.
O/D OFF INDICATOR LIGHT INSPECTION
1. Turn the ignition switch ON.
2. Check if the O/D OFF indicator light lights up when the O/D
main switch is pushed out to OFF and goes off when the O/D
main switch is pushed in to ON.
HINT: If the O/D OFF indicator light does not light up or stay
on all the time, carry out the check for ºO/D OFF Indicator
Light Circuitº on page AT1±88.
DIAGNOSTIC TROUBLE CODE CHECK
1. Turn the ignition switch ON, but do not start the engine.
2. Push in the O/D main switch to ON.
HINT: Warning and diagnostic trouble codes can be read only
when the O/D main switch is ON. If it is OFF, the O/D OFF indi-
cator light up will light continuously and will not blink.
3. Using SST, connect terminals TE1 and E1 of the DLC 1 or
DLC2.
SST 09843±18020
4. Read the diagnostic trouble code indicated by the number of
times the O/D OFF indicator light blinks.
HINT: If the system is operating normally, the light will blink
2 times per second. AT1±34
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

The trouble code is indicated, as shown in the illustration at
left (Diagnostic trouble code º42º is
shown as an example).
HINT: When 2 or more trouble codes are stored in memory,
the lower±numbered code is displayed first. If no diagnostic
trouble code is output, or if a diagnostic trouble code is output
even though no diagnostic trouble code output operation is
performed, check the TE 1 terminal circuit on page AT1±93.
DIAGNOSTIC TROUBLE CODE CHECK
BY USING TOYOTA HAND±HELD
TESTER
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Read the diagnostic trouble codes by following the prompts
on the tester screen.
Please refer to the TOYOTA hand±held tester operator's
manual for further details.
CANCELING DIAGNOSTIC TROUBLE
CODE
After repair of the trouble area, the diagnostic trouble code
retained in the ECM memory must be canceled out by remov-
ing the EFI fuse for 10 seconds or more, with the ignition
switch OFF.
Check that the normal code is output after connecting the
fuse.
ECM TERMINALS STANDARD VALUE
ECM TERMINAL VALUES
MEASUREMENT BY USING TOYOTA BREAK±OUT ±BOX
AND TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA break±out±box and TOYOTA
hand±held tester to the vehicle.
2. Read the ECM input/output values by following the prompts
on the tester screen.
HINT: TOYOTA hand±held tester has a ºSnapshotº function.
This records the measured values and is effective in the diag-
nosis of intermittent problems.
Please refer to the TOYOTA hand±held tester / TOYOTA
break±out box operator's manual for further details.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±35

CHECK TERMINAL TT OUTPUT
VOLTAGE
When a voltmeter is connected to the DLC2, the following
items can be checked:
1. Throttle position sensor signal
2. Brake signal
3. Shift position signal
1. VOLTMETER CONNECTION
Connect the positive (+) probe of the voltmeter to terminal TT
and the negative (±) probe to terminal E1 of the DLC2.
HINT: If a voltmeter with small internal resistance is used, the
correct voltage will not be indicated, so use a voltmeter with
an internal resistance of at least 10 k
/V.
2. TURN IGNITION SWITCH TO ON (DO NOT START THE
ENGINE)
3. CHECK THROTTLE POSITION SENSOR SIGNAL
Check if the voltage changes from approx. 0 V to approx. 8
V when the accelerator pedal is gradually depressed from the
fully closed position.
4. CHECK BRAKE SIGNAL (LOCK±UP CUT SIGNAL)
(a) Open the throttle valve fully to apply approx. 8 V to terminal
TT.
(b) In this condition, check terminal TT voltage when the brake
pedal is depressed and released.
TT terminal voltage:
0 V (When brake pedal is depressed)
8 V (When brake pedal is released)
5. START ENGINE
6. CHECK SHIFT POSITION SIGNAL
(VEHICLE SPEED ABOVE 9 km/h, 6 mph)
Check up±shifting together with terminal TT voltage.
HINT: Check for light shocks from up±shifting and for
changes in the tachometer.
 
 Gear Position
 
 Terminal TT output voltage
1st Gear0V 1st Gear0 V
2nd Gear2V 2nd Gear2 V
 2nd Lock up3V2nd Lock±up3 V 
3rd Gear4V 3rd Gear4 V
3rd Lock up5V 3rd Lock±up5 V
O/D6V O/D6 V
 O/D Lock up7VO/D Lock±up7 V
If terminal TT output voltage check cannot be done, do the
check of TT terminal circuit on page AT1±95. AT1±36
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

STANDARD VALUE OF ECM TERMINAL
* A = (E10), B = (E9) 
 Terminals
 
 Symbols
 
 Wiring
Color 
 Condition
 
 Standard
Value
 B76 ± B69 NSW±E1 B±WeBR IG ON Shift Lever; P or N position Below 3 V
 B76 ± B69 NSW ± E1 B±W eBR IG ON Shift Lever; Other than P or N position 9 ± 14 V
 B3 ± B23 SP2± ± SP2+ G eR IG OFF 560 ± 680

IG OFF10 ± 16
 B10 ± B69 S1 ± E1 W±R eBR Vehicle driving in 2nd gear position 9 ± 14
    IG ON 9 ± 14
    IG OFF 10 ± 16

 B9 ± B69 S2 ± E1 RL eBR Vehicle driving in 2nd or 3rd position 9 ± 14

    IG ON  Below 1.5 V
 B43 ± B65 VTA1±E2 YeBR±B IG ON Accel. pedal is not depressed Below 0.8 V
 B43 ± B65 VTA1 ± E2 Y eBR±B IG ON Accel. pedal is fully depressed 3.2 ± 4.9 V
B64 ± B65IDL1 ± E2ReBR±BIG ONAccel. pedal is not depressedBelow 3 V B64 ± B65 IDL1 ± E2 R eBR±B IG ON Accel. pedal is depressed 9 ± 14 V 
 A2 ± B65
 
 SP1 ± E2
 
 P eBR±B
 
 Ignition switch ON
Turn the rear wheel slowly 
 Repeat 0±8V
or above
 
A3 ± B69
 
KD±E1
 
YeBR
 
IG ON
 Kick±down SW; OFF
(Accel. pedal is not depressed) 9 ± 14 V
 
 
A3 ± B69 
 
KD ± E1 
 
Y eBR 
 
IG ON 
 Kick±down SW; ON
(Accel. pedal is fully depressed) 
 Below 3 V
 A9 ± B69 2±E1 LG±ReBR IG ON Shift Position; 2 position 7.5 ± 14 V
 A9 ± B69 2 ± E1 LG±R eBR IG ON Shift Position; Other than 2 position Below 1.5 V
 A10 ± B69 L±E1 G±BeBR IG ON Shift Position; L position 7.5 ± 14 V

A10 ± B69

L ± E1

G±B eBR

IG ON
Shift Position; Other than L positionBelow 1.5 V A12 ± B69 OD1 ± E1 BR±B eBR Ignition switch ON 4.5 ± 5.5 V 
A18 ± B69
 
M±E1
 
G±YeBR
 
IG ON
 Pattern select SW: MANU 7.5 ± 14 V
 A18 ± B69 M ± E1 G±Y eBR IG ON Pattern select SW: NORM Below 1.5 V
 A28 ± B69 OD2±E1 V±GeBR IG ON O/D main SW; ON 7.5 ± 14 V
 A28 ± B69 OD2 ± E1 V±G eBR IG ON O/D main SW; OFF Below 3 V
 B24 ± B65 OIL ± E2 BR±B eO A/T fluid temperature 110°C (230°F) Below 1 V
AT1±56± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING