TOYOTA SUPRA 1995 Service Repair Manual

EVALUATION
If N "D or N "R time lag is longer than specified:
 Problem Possible cause 
 N"D time lag is longer
 Line pressure too low
Forward clutch worn  N"D time lag is longer Forward clutch worn
 O/D one±way clutch not operating properly
 
 
N"R time lag is longer
 Line pressure too low
 Direct clutch worn
 
 
N"R time lag is longer Direct clutch worn
 First and reverse brake worn
 O/D clutch worn
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±47

HYDRAULIC TEST
MEASURE LINE PRESSURE
NOTICE:
wDo the test at normal operating fluid temp. 50±805C (122±1765F)
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 side.
(c) Chock the 4 wheels.
(d) Fully apply the parking brake.
(e) Start the engine and check idling speed.
(f) Keep your left foot pressed firmly on the brake pedal and shift into D position.
(g) Measure the line pressure when the engine is idling.
(h) Fully depress the accelerator. Quickly read the highest line pressure when engine speed reaches stall
speed.
NOTICE: Release the accelerator pedal and stop test if the wheels begin to rotate before the engine
speed reaches specified stall speed.
(i) In the same manner, do the test in R position. AT2±48
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

SPECIFIED LINE PRESSURE
Line pressure:
 Condition D position kPa (kgf/cm2 psi) R position kPa (kgf/cm2, psi) Idling471±530 (4 8±5 4 68±77)686±785 (7 0±8 0 100±114)Idling471±530 (4.8±5.4, 68±77)686±785 (7.0±8.0, 100±114) 
Stall1 334±1 470 (13 6±15 0 193±213)1 697±2 030 (17 3±20 7 246±294) Stall1,334±1,470 (13.6±15.0, 193±213)1,697±2,030 (17.3±20.7, 246±294)
If the measured pressures are not up to specified values, check the No.5 solenoid valve and retest.
EVALUATION 


Problem
 
 Possible cause
 
If the measured values at allpositions are higher

Throttle cable out of adjustment

Throttle valve defective If the measured values at all positions are higher.
Throttle valve defective

Regulator valve defective
 


If the measured values at allpositions are lower

Throttle cable out of adjustment

Throttle valve defective

Regulator valve defective 


If the measured values at all positions are lower.
Regulator valve defective

Oil pump defective

O/D direct clutch defective
 
Ifpressure is low in the Dposition only
D position circuit fluid leakage
 If pressure is low in the D position only.g

Forward clutch defective
 


Ifpressure is low in the Rposition only

R position circuit fluid leakage

Direct clutch defective
 
If pressure is low in the R position only.
Direct clutch defective

First and reverse brake defective
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±49

MEASURE ACCUMULATOR BACK PRESSURE
NOTICE:
wDo the test at normal operating fluid temp. 50±805C (122±1765F).
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 rear right 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 the RH side head insulator aside.
(c) Remove the passenger side floor carpet and ECM protector.
(d) Connect the SST (check harness A) between ECM and connector of vehicle wire harness.
SST: 09990±01000
(e) Install one test lead probe into the terminal SLN of the ECM wire harness side connector and take care
not to ground the other test lead probe.
HINT: Prepare test leads which are connected with an approximately 8 W light bulb. AT2±50
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

(f) Fully apply the parking brake and chock the 4 wheels.
(g) Start the engine and check idling speed.
(h) Keep your left foot pressed firmly on the brake pedal and shift into D position.
(i) Measure the accumulator back pressure.
(j) With the conditions the same as in (h), ground the other probe or the test lead which has one end inserted
into the terminal SLN of the ECM harness side connector, then measure the accumulator back pressure
again.
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±51

SPECIFIED ACCUMULATOR BACK PRESSURE (D position, Idling)
 Condition of ECM terminal SLN Not ground Ground 
 Accumulator back pressure
kPa (kgf/cm2, psi)
 
 177±255
(1.8±2.6, 26±37) 
 0
EVALUATION
 Problem Possible cause 





The accumulator back pressure is not as specified
(high or low) when the terminal SLN is not ground.




 

Throttle cable out of adjustment

Throttle valve defective

Solenoid modulator valve defective

SLN solenoid valve defective

Accumulator control valve defective
 


The accumulator back pressure does not become
0 kgf/cm2 when the terminal SLN is grounded.

 
SLN solenoid valve defective
AT2±52± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

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
 D O/D
 2 3rd L 1st 
 R
 
 Reverse
 P Pawl 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 AT2±35)
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±53

DTC.
No.Blinking
PatternCircuitDiagnostic Trouble Code Detection Condition
38
42
46
61
62
63
64
A/T fluid
temp.
sensor
No.1 vehicle
speed sensor
No.4 solenoid
valve
No.2 vehicle
speed sensor
No.1 solenoid
valve
No.2 solenoid
valve
No.3 solenoid
circuit
Either (a) or (b) are detected for 0.5 sec. or more:
(a) Temp. sensor resistance less than 79 
(b) After the engine has been operating for 15 minutes or
more, the resistance at the temp. sensor is more
than 156 k
All conditions below are detected for 4 secs. or more:
(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 or more
(c) Park/neutral position switch: OFF (Other than P or N
position)
All conditions below are detected for 1 sec. or more:
(2 trip detection logic)*3
(a) ECM output duty signal to No.4 solenoid in 90% or higher
duty ratio
(b) Current to No.4 solenoid: 330+100 mA or less
All conditions below are detected:
(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)
(1) Solenoid resistance of 8 or less is detected (*) 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 failure are detected less than 8 times, the ECM
memorizes the malfunction code but the O/D OFF indicator
light does not blink.
(1) Solenoid resistance of 8 or less is detected (*) 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 failure are detected less than 8 times, the ECM
memorizes the malfunction code but the O/D OFF indicator
light does not blink.
All conditions below are detected for 1 sec. or more:
(2 trip detection logic)*3
(a) ECM output duty signal to No.3 solenoid in 90% or higher
duty ratio
(b) Current to No.3 solenoid: 450+100 mA or less
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. AT2±54
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING

 
 Trouble Area
 
 O/D OFF Indicator
Light *1Blinks
 
 Memory *2
 
 See
Page
Trouble Area
Light *1 Blinks
Memory
Page 
 
 
 
 

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

A/T fluid temp. sensor

ECM
 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
AT2±70
 
 
 
 
 
 
 

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

No.1 vehicle speed sensor

Telltale light RH

ECM
 
 
 
 
 
 
 

 
 
 
 
 
 
 

 
 
 
 
 
 
 
AT2±72
 
 
 

Harness or connector between No.4 solenoid valve and ECM

No.4 solenoid valve
 
 
 
 
 
 
 
 
 AT2±75
 
 

ECM 
 

 
 

 
 
AT 2±75
 
 
 
 
 
 

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

No.2 vehicle speed sensor

ECM 
 
 
 
 
 

 
 
 
 
 
 

 
 
 
 
 
 
AT2±79
 
 
 
 
 

Harness or connector between No.1 solenoid valve and ECM

No.1 solenoid valve

ECM 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
AT2±82
 
 

Harness or connector between No.2 solenoid valve and ECM

No.2 solenoid valve 
 
 
 
 
 AT2±82 
 


ECM 
 

 
 

 
 

AT 2±82
 
 
 

Harness or connector between No.3 solenoid valve and ECM

No.3 solenoid valve
 
 
 X
 
 
 
 
 
 AT 2 8 5 

No.3 solenoid valve

ECM X  AT2±85
    
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±55

DTC.
No.Blinking
PatternCircuitDiagnostic Trouble Code Detection Condition
67
77
89
O/D direct
clutch speed
sensor
No.5 solenoid
circuit
TRAC ECU
circuit
All conditions below are detected for 4 secs. or more:
(2 trip detection logic)*3
(a) Gear change not being performed.
(b) Gear position: 1st, 2nd or 3rd
(c) T/M input shaft rpm: Less than 300 rpm
(d) T/M output shaft rpm: 1000 rpm or more
Any of condition below are detected:
(2 trip detection logic)*3
(a) SLT
± terminal: 0 V or 5 V for 1 sec. or more.
All conditions below are detected for 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.
AT2±56± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING