TOYOTA SUPRA 1995 Service Repair Manual

DTC 64 Lock±up Solenoid valve Circuit
CIRCUIT DESCRIPTION
The SL solenoid valve is turned ON and OFF by signals from the ECM to control the hydraulic pressure acting
on the lock±up relay valve, which then controls operation of the lock±up clutch.
If a malfunction occurs in this circuit and diagnostic trouble code 64 is stored in memory, the O/D OFF indicator
light does not blink.
Fail Safe Function
If the ECM detects a malfunction, it turns the lock±up solenoid valve OFF.
 DTC No. Diagnostic Trouble Code Detection Condition Trouble Area
 
 
 
 
 
 
64
 
 
 
 
 
 
(a) Solenoid resistance is 8
or lower
(short circuit) when solenoid energized.
(b) Solenoid resistance is 100 k
or higher (open
circuit) when solenoid is not energized.
ECM memorizes diag. trouble code 64 if about (a) or (b)
condition is detected once or more, but ECM does not
start O/D OFF indicator light blinking.




 
V Lock±up solenoid valve
V Harness or connector between
lock±up solenoid valve and ECM
V ECM
WIRING DIAGRAM
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±75

Jack up the vehicle.
Remove the oil pan.
Disconnect the lock±up solenoid valve connector.
Measure resistance between lock-up solenoid
connector and solenoid body.
Resistance: 10 ± 16

Connect lock±up solenoid valve operation noise
when battery positive voltage is applied to the so-
lenoid connector terminal and solenoid body.
Check lock±up solenoid valve.
When battery positive voltage is supplied to
the solenoid valve, check that the solenoid
valve opens.
Replace lock±up solenoid valve.
Electrical Check
Repair or replace harness or connector.
Check harness and connector between lock±up solenoid valve and ECM
(See page IN±30).
Proceed to next circuit inspection shown on matrix chart
(See page AT1±58). However, when diagnostic trouble
code 64 is displayed, check and replace ECM.
Applying 490 kPa (5 kgf/cm2, 71 psi) of com-
pressed air, check that the solenoid valve
does not leak air.
Remove lock±up solenoid valve from valve body.
The lock±up solenoid valve makes operation
noise.
Mechanical Check
AT1±76± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

Throttle Position Sensor Circuit
CIRCUIT DESCRIPTION
The throttle position sensor detects the throttle valve opening angle and sends signals to ECM.
WIRING DIAGRAM
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±77

INSPECTION PROCEDURE
(See page EG±219).
Turn ignition switch ON.
Do not depress the brake pedal during this test.
The voltage will stay at 0 V if depressed.
Voltage changes from 0 V to 8 V by stages.
Check throttle position signal.
Check voltage at the terminal TT of the DLC2
while gradually depressing the accelerator pedal
from the fully closed position to the fully opened
position.
Proceed to next circuit inspection shown on
matrix chart (See page AT1±58).
Replace throttle position sensor.
Repair or replace harness or connector.
Check and replace ECM.
Check harness and connector between ECM and throttle position sen-
sor (See page IN±30).
AT1±78± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

Kick±down Switch Circuit
CIRCUIT DESCRIPTION
The kick±down switch is turned on when the accelerator pedal
is depressed beyond the full throttle opening and sends signals
to ECM.
When the kick±down switch is turned on, the ECM controls gear
shifting according to the programmed shift diagrams.
If a short circuit develops in the kick±down switch, the ECM dis-
regards the kick±down signals and controls shifting at the nor-
mal shift points.
WIRING DIAGRAM
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±79

Connect the Check Harness A to the ECM
(See page EG±404).
Turn ignition switch ON.
Check voltage between terminal KD of ECM connector and body ground.
Measure voltage between terminal KD of ECM
connector and body ground when accel. pedal is
fully depressed or not.
Proceed to next circuit inspection shown on
matrix chart (See page AT1±58).
Released
(Kick±down SW is OFF)
Fully depressed
(Kick±down SW is ON)
Accel. pedalVoltage
9 ± 14 V
Below 3 V
Check kick±down switch.
Disconnect kick±down switch connector (See
page AT1±15).
Measure voltage between terminals 1 and 2 of
kick±down switch connector when kick±down
switch is on and off.
Kick±down switch
ON
OFF
Resistance
C
(continuity)
8
(open)
Replace kick±down switch.
Check harness and connector between ECM and kick±down switch, kick±
down switch and body ground (See page IN±30).
Repair or replace harness connector.
Check and replace ECM.
INSPECTION PROCEDURE
AT1±80± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

Park Neutral Position Switch Circuit
CIRCUIT DESCRIPTION
The park/neutral position switch detects the shift lever position and sends signals to ECM.
The ECM receives signals (NSW, 2 and L) from the park/neutral position switch. When the signal is not sent
to the ECM from the park/neutral position switch, the ECM judges that the shift lever is in the D position.
WIRING DIAGRAM
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±81

Connect the Check Harness A to the ECM
(See page EG±404).
Turn ignition switch ON.
Check voltage between terminals NSW, 2, L of ECM connector and body
ground.
Measure voltage between terminals NSW, 2, L of
ECM connector and body ground when the shift
lever is positioned to the following positions.
Proceed to next circuit inspection shown on
matrix chart (See page AT1±58).
Check park/neutral position switch.
Jack up the vehicle.
Remove park/neutral position switch (See
page AT1±15).
Replace park/neutral position switch.
Check harness and connector between battery and park/neutral position
switch, park/neutral position switch and ECM (See page IN±30).
Repair or replace harness and connector.
Check and replace ECM.
Check continuity between each terminal shown
below when the shift lever is positioned to each
position.
The voltage will drop slighty due to lighting up of the
back up light.
INSPECTION PROCEDURE
AT1±82± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

See
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
The purpose of this circuit is to prevent the engine from stalling, while driving in lock±up condition, when brakes
are suddenly applied.
When the brake pedal is operated, this switch sends a signal to ECM. Then the ECM cancels operation of the
lock±up clutch while braking is in progress.
WIRING DIAGRAM
INSPECTION PROCEDURE
Check operation of stop light.
Check and repair stop light circuit.
Check if the stop lights go on and off normally when the brake pedal is depressed and
released.
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±83

Connect a voltmeter to the terminals TT and
E1 of the DLC2.
Turn ignition switch ON (Do not start the en-
gine).
Fully depress the accelerator pedal until the
voltmeter indicates 8 V and hold it.
Depress and release the brake pedal and
check the voltage.
Check stop light signal.
Brake pedal
Proceed to next circuit inspection shown on
matrix chart (See page AT1±58).
Check harness and connector between ECM and stop light switch
(See page IN±30).
Repair or replace harness or connector
Voltage
Depressed0 V
Released8 V
Check and replace ECM. AT1±84
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING