1995 TOYOTA SUPRA coolant

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

ELECTRONIC CONTROL SYSTEM
The electronic control system, which controls the shift points and the operation of the lock±up clutch, is
composed of the following three parts:
1. Sensors
These sensors sense the vehicle speed, throttle opening and other conditions and send this data to the
ECM in the form of electrical signals.
2. ECM
The ECM determines the shift and lock±up timing based upon the signals from sensors, and controls the
solenoid valves of the hydraulic control unit accordingly.
3. Actuators
These are three solenoid valves that control hydraulic pressure acting on the hydraulic valves to control
shifting and lock±up timing.
SENSORSECM
DRIVING PATTERN
SELECTOR
PARK/NEUTRAL
POSITIOIN SWITCH
THROTTLE POSITIOIN
SENSOR
VEHICLE SPEED
SENSOR
STOP LIGHT SWITCH
O/D MAIN SWITCH
CRUISE CONTROL
ECU
ENGINE COOLANT TEM-
PERATURE SENSOR
A/T FLUID
TEMPERATURE SENSOR
Back±up system
Self±diagnostic
system
Control of lock±
up timing
Control of shift
timing
ACTUATORS
NO. 1
SOLENOID VALVE
NO. 2
SOLENOID VALVE
LOCK±UP
SOLENOID VALVE
O/D OFF INDICA-
TOR LIGHT
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONOPERATIONAT1±7

FUNCTION OF ECU
w Control of Shifting Timing
The ECM has programmed into its memory the optimum shift pattern for each shift lever position (D, 2, L
position) and driving mode (Normal or Manual).
Based on the appropriate shift pattern, the ECM turns No.1 and No.2 solenoid valves on or off in accor-
dance with the vehicle speed signal from the vehicle speed sensor and the throttle opening signal from the
throttle position sensor. In this manner, the ECM operates each shift valve, opening or closing the fluid pas-
sages to the clutches and brakes to permit up±shift or down±shift of the transmission.
HINT: The electronic control system provides shift timing and lock±up control only while the vehicle is travel-
ing forward. In REVERSE, PARK, and NEUTRAL, the transmission is mechanically, not electronically con-
trolled.
w Control of Overdrive
Driving in overdrive is possible if the O/D main switch is on and the shift lever is in the D position. However,
when the vehicle is being driven using the cruise control system (CCS), if the actual vehicle speed drops
to about 4 km/h (2 mph) below the set speed while the vehicle is running in overdrive, the CCS ECU sends
a signal to the ECM to release the overdrive and prevent the transmission from shifting back into overdrive
until the actual vehicle speed reaches the speed set in the CCS memory.
On this model, if the engine coolant temperature falls below 60°C (140°F), the ECM sends a signal to the
ECM, preventing the transmission from up±shifting into overdrive.
w Control of Lock±Up System
The ECM has programmed in its memory a lock±up clutch operation pattern for each driving mode (Normal
of Manual). Based on this lock±up pattern, the ECM turns lock±up solenoid valve on or off in accordance
with the vehicle speed signals received from the vehicle speed sensor and the throttle opening signals from
the throttle position sensor.
Depending on whether lock±up solenoid valve is on or off, the lock±up relay valve performs changeover
of the fluid passages for the converter pressure acting on the torque converter clutch to engage or disen-
gage the lock±up clutch.
Mandatory Cancellation of Lock±Up System:
If any of the following conditions exist, the ECM turns off lock±up solenoid valve to disengage the lock±up
clutch.
1) The brake light switch comes on (during braking).
2) The IDL points of the throttle position sensor close (throttle valve fully closed).
3) The vehicle speed drops 4 km/h (2 mph) or more below the set speed while the cruise control system
is operating.
4) The engine coolant temperature falls below 60°C (140°F) and vehicle speed is under 60 km/h (37
mph), or 35°C (95°F) and vehicle speed is under 40 km/h (25 mph).
The purpose of 1) and 2) above is to prevent the engine from stalling if the rear wheels lock up.
The purpose of 3) is to cause the torque converter clutch to operate to obtain torque multiplication. The
purpose of 4) is both to improve general driveability, and to speed up transmission warm±up.
Also, while the lock±up system is in operation, the ECM will temporarily turn it off during up±shift or down±
shift in order to decrease shifting shock. AT1±8
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONOPERATION

 
 
 
8
 
 
 
No.1 and No.2 Vehicle Speed Sensor
 
 
 
Detects the vehicle speed. Ordinarily, transmission control
uses signals from the No.2 vehicle speed sensor, and the
No.1 vehicle speed sensor is used as a back±up.
 9Engine Coolant Temp SensorDetects the engine coolant temp 9Engine Coolant Temp. SensorDetects the engine coolant temp.
 
10ECMControls the engine and transmission actuators based on 10ECMControls the engine and transmission actuators based on
signals from each sensor. 
 11No 1 and No 2 Solenoid ValvesControl the hydraulic pressure applied to each shift valve,
 11No.1 and No.2 Solenoid ValvesControl the hydraulic ressure a lied to each shift valve,
and control the gear position and timing.
 
12
Lock±up Solenoid Valve
(For lock up control pressure modulaControls the hydraulic pressure applied to the lock±up 
 
12(For lock±up control pressure modula-
tion)Controls the hydraulic ressure a lied to the lock u
clutch and controls lock±up timing.
 
13O/D OFF Indicator Light
Blinks and warns the driver, while the O/D main switch is
pushed in when the electronic control circuit is malfunction 
 
13O/D OFF Indicator Lightpushed in, when the electronic control circuit is malfunction-
ing.
 
14Kick down SwitchDetects if the accelerator pedal is depressed beyond the 14Kick±down SwitchDetects if the accelerator edal is de ressed beyond the
full throttle valve opening position.
 
15A/T Fluid Temp SensorDetects the A/T fluid temp 15A/T Fluid Temp. SensorDetects the A/T fluid temp.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONOPERATIONAT1±11

PROBLEM SYMPTOM CONFIRMATION
Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of
the trouble. If the problem is that the transmission does not up±shift, does not down±shift, or the shift point
is too high or too low, conduct the following road test to confirm the automatic shift schedule and simulate
the problem symptoms.
ROAD TEST
NOTICE: Do the test at normal A/T fluid operating temp.
50±80°C (122 ± 176°F).
1. D POSITION TEST (NORM PATTERN)
Shift into the D position and keep the accelerator pedal
constant at the full throttle valve opening position, and check
the following points:
(a) Check up±shift operation.
Check that 1±2, 2±3 and 3±O/D up±shift takes place, at the
shift point shown in the automatic shift schedule.
(See page AT1±96)
HINT:
(1) O/D Gear Up±shift Prohibition Control.
w Coolant temp. is 60°C (140°F) or less.
w If there is a 10 km/h (6 mph) difference between the set
cruise control speed and
wvehicle speed.
wO/D main switch is pushed ON.
w(During O/D OFF, indicator light lights up.)
(2) O/D Gear Lock±up Prohibition Control.
w Brake pedal is depressed.
w Coolant temp. is 60°C (140°F) or less.
(b) Check for shift shock and slip.
Check for shock and slip at the 1±2, 2±3 and 3±O/ D up±
shifts.
(c) Check for abnormal noise and vibration.
Run at the D position lock±up or O/D gear and check for ab-
normal noise and vibration.
HINT: The check for the cause of abnormal noise and vibra-
tion must be performed very thoroughly as it could also be
due to loss of balance in the torque converter clutch, etc.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±37

(d). Check kick±down operation.
While running in the D position, 2nd, 3rd and O/D gears,
check to see that the possible kick±down vehicle speed limits
for 2 " 1, 3 " 2 and O/D " 3 kick±downs conform to those
indicated on the automatic shift schedule. (See page
AT1±96)
(e) Check for abnormal shock and slip at kick±down.
(f) Check the lock±up mechanism.
(1) Drive in D position, O/D gear, at a steady speed (lock±up
ON) of about 61 km/h (38 mph).
(2) Lightly depress the accelerator pedal and check that the
RPM does not change abruptly.
If there is a big jump in RPM, there is no lock±up.
2. D POSITION TEST (MANU PATTERN)
Shift into the D position and hold the accelerator pedal
constant at the full throttle valve opening position, and check
the following points:
(a) Check up±shift operation.
2±3 and 3±O/D up shifts should take place, and shift points
should conform to those shown in the automatic shift sched-
ule.
(See page AT1±96)
HINT:
w O/D up±shift or lock±up will not occur when the engine
coolant temp. is below 605C (1405F) and speed is under
63 km/h (39 mph), or if there is a 10 km/h (6 mph)
difference between the set cruise control speed.
w 3rd up±shift or lock±up will not occur when engine
coolant temp. is 355C (955F) and speed is under 40 km/h
(25 mph).
(b) Check for shift shock and slip.
In the same manner, check the shock slip at the 2 " 3 and
3 " O/D up±shifts. AT1±38
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

AT1±83AT1±85AT1±88AT1±91AT1±64EG±312AT1±56AT1±60AT1±62
Stop light switch
circuitPattern select switch
circuitO/D switch O/D OFF
indicator light circuitECMA/T fluid temp.
sensor circuitO/D cancel signal
circuitEngine coolant
temp. switch circuitOFF±Vehicle repairmatrix chartOn±Vehicle repairmatrix chart
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±59

LOCK±UP POINT
NORM Mode
 
 
D position km/h (mph)
Throttle valve opening 5% 
 Lock±up ON
 
 Lock±up OFF
 3rd Gear (O/D switch OFF) 56±62 (35±39) 53±59 (35±39)
 O/D Gear 56±62 (35±39) 53±59 (35±39)
MANU Mode
 
 D position km/h (mph)
Throttle valve opening 5%
 
 Lock±up ON
 
 Lock±up OFF
 
 3rd Gear (O/D switch OFF)
 
 98±105 (61±65)
 
 92±99 (57±62)
 O/D Gear 163±175 (101±109) 56±62 (35±39)
HINT:
(1) There is no lock±up in the 2 and L positions.
(2) In the following cases, the lock±up will be released regardless of the lock±up pattern.
w When the throttle valve is completely closed.
w When the brake light switch is ON.
(3) Shift up to 3rd will not occur when the engine coolant temp. is below 35°C (95°F) and the vehicle
speed is below 40 km/h (25 mph).
(4) Shift±up to O/D will not occur when the engine coolant temp. is below 60°C (140°F) and the vehicle
speed is below 63 km/h (39 mph)
(5) When the vehicle speed drops to 10 km/h (6 mph) or more below the cruise control set vehicle speed,
shift down from O/D to 3rd occurs.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONSERVICE SPECIFICATIONSAT1±97