TOYOTA SUPRA 1995 Service Repair Manual

Check No.3 solenoid valve.
1. Jack up the vehicle.
2. Remove the oil pan.
3. Disconnect the solenoid connector
Measure resistance between terminal 1 and 2 of
the solenoid connector.
Resistance: 3.5 Ð 3.9

Check solenoid resistance
Check solenoid operation
Connect positive
lead with an 8 Ð 10 W bulb to
terminal 1 of solenoid connector and negative 
lead to terminal 2, then check the movement of the
valve.
When battery positive
voltage is applied.
direction in illustration
at left.
When battery positive
voltage is cut off.
Valve moves in
Valve moves in
direction in illustration
at left.
Replace No.3 solenoid valve.

Check solenoid's operation
1. Prepare a variable power supply.
2. Connect positive
lead of the variable power
supply to terminal 1 of solenoid connector and
negative  lead to terminal 2.
3. Check the movement of the valve when the
voltage is gradually increased. (A current
greater than 1A should not be supplied.)
As the voltage is increased, the valve should move
slowly in the direction.
4. Check the movement of the valve when the volt±
age is cut off.
The valve should return in the direction.
Go to step
INSPECTION PROCEDURE
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±87

Check harness and connector between battery and No.3 solenoid valve, No.3
solenoid valve and ECM (See page IN±30).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on matrix
chart (See page AT2±64). However, when diagnostic
trouble code 64 is displayed, check and replace
ECM.
AT2±88± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

DTC No.Trouble Area
67

O/D direct clutch speed sensor

Harness or connector between O/D direct
clutch speed sensor and ECM

ECMAll conditions below are detected for 4 secs. or
more.
(2 trips detection logic)*
(a) Gear position: 1st, 2nd or 3rd
(b) T/M input shaft rpm: 1000 rpm or more
(c) T/M output shaft rpm: Less than 300 rpm
(d) NSW OFF (other than P or N position)
Diagnostic Trouble Code Detection Condition

*: See page AT2±58

Waveform between terminals NCO+ and NCO± during engine idling.
This sensor detects the rotation speed of the O/D input shaft
from the rotation of the O/D direct clutch drum.
Its construction is the same as that of the No.2 vehicle speed
sensor (See page AT2±79).
By comparing the O/D direct clutch speed signal and the No.2
vehicle speed sensor signal, the ECM detects the shift timing
of the gears and appropriately controls the engine torque and
hydraulic pressure in response to various conditions, thus
performing smooth gear shift.O/D Direct Clutch Drum
O/D Direct Clutch
Speed Sensor
CIRCUIT DESCRIPTION
DTC 67 O D Direct Clutch Speed Sensor Circuit
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±89

WIRING DIAGRAM
INSPECTION PROCEDURE
Check resistance between terminals NCO+ and NCO± of ECM.
Connect the Check Harness A to the ECM (See
page EG±510).
Check Resistance between terminals NCO
+ and
NCO± of ECM.
Resistance: 560 Ð 680 
Proceed to next circuit inspection shown on ma-
trix chart (See page AT2±64). However, when diag-
nostic trouble code 67 is displayed, check and re-
place ECM.
G to
AT2±90
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

Check O/D direct clutch speed sensor.
Remove the O/D direct clutch speed sensor from
the transmission (See page AT2±17).
Measure resistance between the terminals 1 and 2
of the O/D direct clutch speed sensor.
Resistance: 560 Ð 680 
Check and repair harness and connector between
ECM and O/D direct clutch speed sensor (See page
IN±30).

Check the speed sensor function
Check voltage between the terminals 1 and 2 of
the speed sensor when a magnet is put close to
the front end of the speed sensor then taken away
quickly.
Voltage is generated intermittently.
The voltage generated is extremely low.
Replace O/D direct clutch speed sensor.
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±91

DTC 77 No.5 Solenoid Valve Circuit (For Line Pressure Modulation)
CIRCUIT DESCRIPTION
The throttle pressure that is applied to the primary regulator valve (which modulates line pressure) causes the
No.5 solenoid valve, under electronic control, to precisely and minutely modulate and generate line pressure
according to the accelerator pedal effort, or engine power output detected. This reduces the fluctuation of line
pressure and provides smooth shifting characteristics.
Upon receiving the throttle valve opening angle signal, ECM controls the line pressure by sending a predeter-
mined duty ratio to the No.5 solenoid valve located in the valve body, activating the solenoid valve, modulating
the line pressure, generating throttle pressure.
 DTC No. Diagnostic Trouble Code Detection Condition Trouble Area
 
 
 
 
77
 
 
 
 
Any of condition below are detected. (2 trip
detection logic)

SLT
± terminal: 0 V or 5 V for 1 sec. or more.
 
 
 
 

No.5 solenoid valve

Harness or connector between No.5
solenoid valve and ECM

ECM
AT2±92± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

INSPECTION PROCEDURE
Check No.5 solenoid valve.
1. Jack up the vehicle.
2. Remove the oil pan.
Resistance: 3.6 Ð 4.0

Check solenoid resistance
Check solenoid operation
Connect positive
lead with an 8 Ð 10 W bulb to
terminal 1 of solenoid connector and negative 
lead to terminal 2, then check the movement of the
valve.
When battery positive
voltage is applied.direction in illustration
at left.
When battery positive
voltage is cut off.direction in illustration
at left.
Replace No.5 solenoid valve.

Check solenoid operation
Go to step
1. Disconnect the solenoid connector.
2. Measure resistance between terminals 1 and 2
of solenoid connector.
Valve moves in
Valve moves in
1. Prepare a variable power supply.
2. Connect positive
lead of the variable power
supply to terminal 1 of solenoid connector and
negative  lead to terminal 2.
3. Check the movement of the valve when the
voltage is gradually increased. (A current
greater than 1A should not be supplied.)
As the voltage is increased, the valve should move
slowly in the direction.
4. Check the movement of the valve when the volt±
age is cut off.
The valve should return in the direction.
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±93

Repair or replace harness or connector.
Proceed to next circuit inspection shown on matrix
chart (See page AT2±64). However, when diagnostic
trouble code 77 is displayed, check and replace
ECM.
Check harness and connector between battery and No.5 solenoid valve, No.5
solenoid valve and ECM (See page IN±30).
AT2±94± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

DTC 89 TRAC ECU Circuit
CIRCUIT DESCRIPTION
When the transmission is in the shift up or stall condition, the TRAC ECU sends a sub±throttle valve close
signal to the sub±throttle actuator.
 DTC No. Diagnostic Code Detection Condition Trouble Area 
 
 
 
 
 
 
 
 
89
 
 
 
 
 
 
 
 
 

All conditions below are detected 5 secs. or
more.
(a) No.1 vehicle speed sensor: 9 km/h (5.6 mph)
or more
(b) Mirror check of TRAC ECU input signal is
abnormal.
(c) TRAC ECU input signal does not inform to
ECM.
(d) TRAC ECU input signal order is abnormal.
 
 
 
 
 
 
 
 
 

Harness or connector between TRAC ECU
and ECM

TRAC ECU
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±95

INSPECTION PROCEDURE
Repair or replace harness or connector.
If the same code is still output after the diagnostic trouble code is deleted, check the contact
condition of each connection.
If the connections are normal, the TRAC ECU may be defective.
Check harness and connector between ECM and TRAC ECU (See page
IN±30).
Substitute another TRAC ECU.
Check diagnostic trouble code of TRAC ECU (See page BR±128).
AT2±96± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING