TOYOTA SUPRA 1995 Service Repair Manual

EVALUATION
ProblemPossible cause Problem Possible cause
 
 
 
 
 
(a) Stall speed low in D and R positions.
 
 
 
 
 
wEngine output may be insufficient.
wStator one±way clutch is operating properly
HINT:
If more than 600 rpm below the specified value, the
torque converter clutch could be faulty.
 
 (b) Stall speed high in Dposition
wLine pressure too low
wForward clutch slipping
 
 
(b) Stall speed high in D position.Forward clutch sli ing
wNo.2 one±way clutch not operating properly
wO/D one±way clutch not operating properly
 
 
(c) Stall speed high in Rposition
wLine pressure too low
wDirect clutch slipping
 
 
(c) Stall speed high in R position.Direct clutch sli ing
wFirst and reverse brake slipping
wO/D clutch one±way clutch not operating properly
 
 (d) Stall speed high in D and Rpositions
wLine pressure too low
wImproper fluid level
 
(d) Stall speed high in D and R positions.wImproper fluid level
wO/D one±way clutch not operating properly
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±45

TIME LAG TEST
When the shift lever is shifted while the engine is idling, there will be a certain time lapse or lag before the
shock can be felt. This is used for checking the condition of the O/D direct clutch, forward clutch, direct
clutch, and first and reverse brake.
NOTICE:
wDo the test at normal operating fluid temp. 50±80
°C (122±176 °F).
wBe sure to allow a one minute interval between tests.
wTake 3 measurements and take the average value.
MEASURE TIME LAG
(a) Fully apply the parking brake
(b) Start the engine and check idle speed.
Idle speed:
700 + 50 rpm (In N position and air conditioner OFF)
(c) Shift the shift lever from N to D position. Using a stop watch, measure the time it takes from shifting the
lever until the shock is felt.
In same manner, measure the time lag for N " R.
Time lag:
N
" D Less than 1.2 seconds
N
" R Less than 1.5 seconds
AT1±46± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

EVALUATION
If N " D or N "R time lag is longer than specified:
 Problem Possible cause
 
 
N"D time lag is longer
 
 V Line pressure too low
V Forward clutch worn
 
 
N"D time lag is longer 
 
Forward clutch worn
V O/D one±way clutch not operating properly
V Accumulator back pressure too low
 
 
N"R time lag is longer
V Line pressure too low
V Direct clutch worn
VFirst and reverse brake worn 
 
 
N"R time lag is longerV First and reverse brake worn
V O/D clutch one±way clutch not operating properly
V Accumulator back pressure too low
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±47

HYDRAULIC TEST
MEASURE LINE PRESSURE
NOTICE:
wDo the test at normal operating fluid temp. 50±80 5C (122±176 5F).
wThe line pressure test should always be carried out in pairs. One technician should observe the
conditions of wheels or wheel stoppers outside the vehicle while the other is doing the test.
wBe careful to prevent the oil pressure gauge hose from interfering with the exhaust pipe.
(a) Warm up the transmission fluid.
(b) Remove the test plug on the transmission case left side and connect the oil pressure gauge (SST). SST
09992±00094 (Oil pressure gauge)
HINT: Connecting the oil pressure gauge will be made easier by moving LH side heat insulator aside.
(c) Fully apply the parking brake and chock the 4 wheels.
(d) Start the engine and check idling RPM.
(e) Keep your left foot pressed firmly on the brake pedal and shift into D position.
(f) Measure the line pressure when the engine is idling.
(g) Press the accelerator pedal all the way down. Quickly read the highest line pressure when engine speed
reaches stall speed.
(h) In the same manner, do the test in R position. AT1±48
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

SPECIFIED LINE PRESSURE
 Line pressure D position kPa (kgf/cm2,psi) R position kPa (kgf/cm2, psi)
 Idling363 422 (3 7 4 3 53 61)500 598 (5 1 6 1 73 88)Idling363±422 (3.7±4.3, 53±61)500±598 (5.1±6.1, 73±88) 
Stall902 1 147 (9 2 11 7 131 166)1 236 1 589 (12 6 16 2 179 230) Stall902±1,147 (9.2±11.7, 131±166)1,236±1,589 (12.6±16.2, 179±230)
If the measured pressures are not up to specified values, recheck the throttle cable adjustment and retest.
EVALUATION
 Problem Possible cause 
 
If the measured values at allpositions are higher
V Throttle cable out of adjustment
Throttle valve defective  If the measured values at all positions are higher.V Throttle valve defective
V Regulator valve defective
 
 
 If the measured values at allpositions are lower
V Throttle cable out of adjustment
V Throttle valve defective
Regulator valve defective 
 
If the measured values at all positions are lower.V Regulator valve defective
V Oil pump defective
V O/D direct clutch defective
 
Ifpressure is low in the Dposition onlyV D position circuit fluid leakage  If pressure is low in the D position only. D osition circuit fluid leakage
V Forward clutch defective 
 Ifpressure is low in the Rposition only
V R position circuit fluid leakage
Direct clutch defective  If pressure is low in the R position onlyV Direct clutch defective
V First and reverse brake defective
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±49

MANUAL SHIFTING TEST
HINT: With this test, it can be determined whether the trouble
is within the electrical circuit or is a mechanical problem in the
transmission.
1. DISCONNECT SOLENOID WIRE
2. INSPECT MANUAL DRIVING OPERATION
Check that the shift and gear positions correspond with the
table below.
 Shift Position Gear Position
DO/D DO/D
 23rd23rd 
L1st L1st
RReverse RReverse
PPawl Lock PPawl Lock
HINT: If the L, 2 and D position gear positions are difficult to
distinguish, do the following road test.
wWhile driving, shift through the L, 2 and D positions.
Check that the gear change corresponds to the shift
position.
If any abnormality is found in the above test, the problem is
in the transmission itself.
3. CONNECT SOLENOID WIRE
4. CANCEL OUT DIAGNOSTIC TROUBLE CODE
(See page AT1±35) AT1±50
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

±Memo±
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±51

DTC
No.Blinking
PatternCircuitDiagnostic Trouble Code Detection Condition
38
42
Either (a) or (b) are detected for 0.5 sec. or more.
(a) Temperature sensor resistance less than 79 
(b) After the engine has been operating for 15 minutes or more,
the resistance at the temperature sensor is more than 156 k
All conditions below are detected 500 times or more continuously.
(2 trip detection logic) *3
(a) No No. 1 vehicle speed sensor signal in 16 pulses of No. 2
vehicle speed sensor signal.
(b) Vehicle speed: 9 km/h (5.6 mph) or more for 4 secs. or more.
(c) Park/neutral position switch: OFF (Other than P or N position)
A/T fluid
temp.
sensor
No. 1 vehicle
speed sensor
No. 2 vehicle
speed sensor
All conditions below are detected 500 times or more continuously.
(2 trip detection logic) *3
(a) No No. 2 vehicle speed sensor signal in 4 pulses of No. 1
vehicle speed sensor signal.
(b) Vehicle speed: 9 km/h (5.6 mph) or more for 4 secs. or more.
(c) Park/neutral position switch: OFF (Other than P or N position)
No. 1
solenoid
valve
(1) Solenoid resistance of 8 or less is detected (*) 8 times or
more when No. 1 solenoid is energized.
(2) Solenoid resistance of 100 k or more is detected (*) 8 times
or more when No. 1 solenoid is not energized.
(*) If the above failures are detected less than 8 times, the ECM
memorizes the malfunction code but the O/D OFF indicator
light does not blink.
No. 2
solenoid
valve
(1) Solenoid resistance of 8 or less is detected (*) 8 times or
more when No. 2 solenoid is energized.
(2) Solenoid resistance of 100 k or more is detected (*) 8 times
or more when No. 2 solenoid is not energized.
(*) If the above failures are detected less than 8 times, the ECM
memorizes the malfunction code but the O/D OFF indicator
light does not blink.
Lock±up
solenoid
valve
(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 above (a) or (b)
condition is detected once or more, but ECM does not start
O/D OFF indicator light blinking.
61
62
63
64
DIAGNOSTIC TROUBLE CODE CHART
If a diagnostic trouble code is displayed during the diagnostic trouble code check, check the circuit listed
for that code in the table below and proceed to the page given. AT1±52
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

AT1±64
AT1±66
AT1±69
AT1±72
AT1±72
AT1±75
Trouble AreaO/D OFF Light *1
BlinksMemory *2See
Page

Harness or connector between A/T fluid temp. senter and
ECM.

A/T fluid temp. sensor.

ECM

Harness or connector between No. 1 vehicle speed sensor
and ECM.

No. 1 vehicle speed sensor.

Telltale light RH.

ECM

Harness or connector between No. 2 vehicle speed sensor
and ECM.

No. 2 vehicle speed sensor.

ECM

Harness or connector between No. 1 solenoid and ECM.

No. 1 solenoid valve.

ECM

Harness or connector between No. 2 solenoid and ECM.

No. 2 solenoid valve.

ECM

Harness or connector between lock±up solenoid and ECM.

Lock±up solenoid valve.

ECM
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT1±53

*1 ªº mark means ºO/D OFFº indicator light blinks once every 2 seconds.
ºXº mark means ºO/D OFFº indicator light never blinks.
*
2ªº marks means the ECM memorizes the malfunction code if the ECM detects the diagnostic trouble code
detection condition.
*
3 This indicates items for which º2 trip detection logicº is used. With this logic, when a logic malfunction is
first detected, the malfunction is temporarily stored in the ECM memory. If the same case is detected again
during the second drive test, this second detection causes the O/D OFF Indicator Light to blink. The 2 trip
repeats the same mode twice. (However, the IG switch must be turned OFF between the 1st trip and 2nd
trip.)
HINT:
wIf the malfunction returns to normal while a malfunction warning is being output, the O/D OFF indicator
light stops blinking and goes off.
However, the diagnostic trouble code is retained in memory until it is cleared from memory.
wIf the diagnosis system outputs a diagnostic trouble code even though the O/D OFF indicator was not
blinking, there is intermittent trouble. Check all the connections in the circuits corresponding to that
code.
wIf the vehicle speed sensors No.1 and No.2 happen to fail simultaneously, the ECM will neither alert
the driver by blinking the O/D OFF indicator nor record any diagnostic trouble code. It will, however,
decide that the vehicle can be driven only in 1st and none of the other gears, so shifting upward will
then be prohibited.
wCodes 46, 62, 63 and 64 are limited to short or open circuits in the electrical system comprised of the
solenoids, wire harnesses, and connectors. The ECM is unable to detect mechanical trouble (sticking,
for example) in the solenoid valves. AT1±54
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING