Engine TOYOTA SUPRA 1995 Service Service Manual

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

ARRANGEMENT OF COMPONENTS
 No. Components Function
 
1Pattern Select Switch Selects the Manual mode or the Normal mode for shift 1 Pattern Select Switch Selects the Manual mode or the Normal mode for shift
and lock±up timing. 
2Crankshaft Position SensorDetects the engine speed 2 Crankshaft Position Sensor Detects the engine speed.
 3Park/Neutral Position SwitchDetects the shift lever position

3 Park/Neutral Position Switch Detects the shift lever position.
 
4Stop Light SwitchDetects if the brake pedal is depressed 4 Stop Light Switch Detects if the brake pedal is depressed.
5Throttle Position SensorDetects the throttle valve opening angle 5 Throttle Position Sensor Detects the throttle valve opening angle.
 
6O/D Main Switch Prevents up±shift to the O/D gear if the O/D main 6 O/D Main Switch Prevents u shift to the O/D gear if the O/D main
switch is off.
 
 7Cruise Control ECU
This ECU prevents the transmission from shifting into
O/D and prohibits lock up control when the vehicle's 7 Cruise Control ECU O/D and prohibits lock±up control when the vehicle's
speed drops below the cruise control set speed parameter.
AT1±10± 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

09032±00100 Oil Pan Seal Cutter
09308±10010 Oil Seal Puller
09325±40010 Transmission Oil Plug
09350±30020 TOYTOA Automatic Transmission
Tool Set
(09351±32010) One±way Clutch Test Tool
(09351±32020) Stator Stopper
09843±18020 Diagnosis Check Wire
09990±01000 Engine Control Computer Check
Harness ªAº
09992±00094 Automatic Transmission Oil
Pressure Gauge Set
PRECAUTION
PRECAUTIONS
When working with FIPG material, you must observe the following.
wUsing a razor blade and gasket scraper, remove all the old packing (FIPG) material from the
gasket surfaces.
wThoroughly clean all components to remove all the loose material.
wClean both sealing surfaces with a non±residue solvent.
wApply the seal packing in an approx. 1 mm (0.04 in.) bead along the sealing surface.
wParts must be assembled within 10 minutes of application. Otherwise, the packing (FIPG)
material must be removed and reapplied.
If the vehicle is equipped with a mobile communication system, refer to the precaution in the IN sec-
tion.
PREPARATION
SST (SPECIAL SERVICE TOOLS)
AT1±12± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONPRECAUTION

11. DISCONNECT OIL COOLER PIPES
(a) Remove the 3 bolts and oil cooler pipe clamps.
(b) Disconnect the 2 oil cooler pipes.
Torque: 34 NVm (350 kgfVcm, 25 ftVlbf)
12. REMOVE TORQUE CONVERTER CLUTCH MOUNTING
BOLTS
(a) Remove the engine under cover.
(b) Remove the converter plate.
(c) Turn the crankshaft to gain access to each bolt.
Remove the 6 bolts.
Torque: 33 NVm (340 kgfVcm, 25 ftVlbf)
13. JACK UP TRANSMISSION
14. REMOVE REAR MOUNTING
Remove the 4 bolts and rear mounting.
Torque: 25 NVm (260 kgfVcm, 19 ftVlbf)
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONASSEMBLY REMOVAL AND INSTALLATIONAT1±25

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

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

(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

(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 made with extreme care as it could also be due
to loss of balance in the propeller shaft, differential, torque
converter clutch, etc.
(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 3 " 2 and O/D " 3 kick±downs conform to those indi-
cated on the automatic shift schedule.
(See page AT1±96)
(e) Check for abnormal shock 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 172 km/h (107 mph).
(2) Lightly depress the accelerator pedal and check that the
engine RPM does not change abruptly.
If there is big jump in the engine RPM there is no lock ±up.
3. 2 POSITION TEST (NORM PATTERN)
Shift into the 2 position and, while driving with the accelerator
pedal held constantly at the full throttle valve opening posi-
tion, check on the following points:
(a) Check up±shift operation.
Check to see that the 1 " 2 up±shift takes place and that the
shift point conforms to the automatic shift schedule.
(See page AT1±96)
HINT: There is no O/D up±shift and lock±up in the 2 position.
(b) Check engine braking.
While running in the 2 position and 2nd gear, release the ac-
celerator pedal and check the engine braking effect.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±39

(c) Check for abnormal noise at acceleration and deceleration,
and for shock at up±shift and down±shift.
4. 2 POSITION TEST (MANU PATTERN)
Shift into the 2 position and while driving with the accelerator
pedal held constantly at the full throttle valve opening posi-
tion, push in one of the pattern selectors and check these
points:
(a) Check no up±shift.
While running in the 2 position, check to see that there is no
up±shift to 3rd gear.
(b) Check engine braking.
While running in the 2 position and 2nd gear, release the ac-
celerator pedal and check the engine braking effect.
(c) C h e c k f o r abnormal noise during acceleration and
deceleration.
5. L POSITION TEST
Shift into the L position and while driving with the accelerator
pedal held constantly at the full throttle valve opening posi-
tion check the these points:
(a) Check no up±shift.
While running in the L position, check that there is no up±shift
to 2nd gear. AT1±40
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING