transmission oil LEXUS SC400 1991 Service Repair Manual

AT00S±01
PRELIMINARY CHECK
1. CHECK FLUID LEVELHINT:
wDrive the vehicle so that the engine and transmission
are at normal operating temperature.
Fluid temp.: 70±80 5C (158±176 5F)
w Only use the COOL range on the dipstick as a rough
reference when the fluid is replaced or the engine does
not run.
(a) Park the vehicle on a level surface and set the parking brake.
(b) With the engine idling and the brake pedal depressed, shift the shift lever into all positions from P to L position and return
to P position.
(c) Pull out the transmission dipstick and wipe it clean.
(d) Push it back fully into the tube.
(e) Pull it out and check that the fluid level is in the HOT range. If the level is at the low side, add fluid.
Fluid type:
ATF TYPE T±II or Equivalent
NOTICE: Do not overfill.
2. CHECK FLUID CONDITION If the fluid smells burnt or is black, replace it.
3. REPLACE TRANSMISSION FLUID
(a) Remove the drain plug and drain the fluid.
(b) Reinstall the drain plug securely.
(c) With the engine OFF, add new fluid through the oil filler tube.
Fluid type:
ATF TYPE T±II or Equivalent
Capacity:
Total: 8.2 liters (8.7 US qts, 7.2 lmp. qts)
Drain and refill: 1.9 liters (2.0 US qts, 1.7 lmp. qts)
(d) Start the engine and shift the shift lever into all positions fromP to L position and then shift into P position.
(e) With the engine idling, check the fluid level. Add fluid up to the
COOL level on the dipstick.
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(f) Check the fluid level at the normal operating temperature70±80
C (158±176
F) and add as necessary.
NOTICE: Do not overfill.
4. CHECK FLUID LEAKS
Check for leaks in the transmission.
If there are leaks, it is necessary to repair or replace O±rings,
seal packings, oil seals, plugs or other parts.
5. INSPECT AND ADJUST THROTTLE CABLE
(a) Remove the 2 bolts, nut and throttle body cover.
(b) Check that the throttle valve is fully closed.
(c) Check that the inner cable is not slack.
(d) Measure the distance between the outer cable end and stopper on the cable.
Standard distance:
0±1 mm (0±0.04 in.)
If the distance is not standard, adjust the cable by the adjust-
ing nuts.
(e) Install the throttle body cover, and two bolts and nut.
6. INSPECT AND ADJUST SHIFT LEVER POSITION When shifting the shift lever from the N position to other posi-
tions, check that the lever can be shifted smoothly and accu-
rately to each position and that the position indicator correctly
indicates the position.
If the indicator is not aligned with the correct position, carry
out the following adjustment procedures:
(a) Loosen the nut on the control shaft lever.
(b) Push the control shaft lever fully rearward.
(c) Return the control shaft lever 2 notches to N position.
(d) Set the shift lever to N position.
(e) While holding the shift lever lightly toward the R position side,
tighten the shift lever nut.
(f) Start the engine and make sure that the vehicle moves forward when shifting the lever from the N to D position and
reverses when shifting it to the R position.
AT±48
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MEASURE LINE PRESSURE
NOTICE:
Perform the test at normal operating fluid temperature 50±80 C (122±176 F).
 The line pressure test should always be carried out in pairs. One technicia\
n should observe the
conditions of wheels or wheel stoppers outside the vehicle while the other is perf\
orming the test.
 Be 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
HINT: Connecting the oil pressure gauge will be made easier by moving LH sid\
e 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 p\
osition.
(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 speedreaches stall speed.
(h) In the same manner, perform the test in R position. AT±54
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SPECIFIED LINE PRESSURE
 
Condition
 
D positionkPa (kgf/cm2, psi)
 
R positionkPa (kgf/cm2, psi) 

Idling
 

382±441 (3.9±4.5, 55±64)
 

637±716 (6.5±7.3, 92±104) 

Stall
 

1,265±1,402 (12.9±14.3, 183±203)
 

1,726±2,060 (17.6±21.0, 250±299)
If the measured pressures are not up to specified values, recheck the thro\
ttle cable adjustment and perform
a retest.
EVALUATION
 Problem\
 \
Possible cause
 \
 \

Throttle cable out of adjustment If the measured values at all positions are higher.\
 \
 Throttle valve defective 


\

\

\

Regulator valve defective
 \
 \
 Throttle cable out of adjustment
 \
 \
 Throttle 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.\
 \
 Forward clutch defective 


\

\

\

R position circuit fluid leakage
 If pressure is low in the R position only.\
 \
 Direct clutch defective
 \
 \
 First and reverse brake defective
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MEASURE ACCUMULATOR BACK PRESSURE
AT0QU±01
NOTICE:
Perform the test at normal operating fluid temperature 50±80 C (122±176 F).
 Be 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 connec\
t the oil pressure gauge SST.
SST 09992±00094
HINT: Connecting the oil pressure gauge will be made easier by moving the RH \
side head insulator aside.
(c) Remove the passenger side No.2 under cover 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 harnes\
s 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 l\
ight bulb.
AT±56
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OKNG
INSPECTION PROCEDURE
1Check No. 4 solenoid valve.
C
OK
P
C
OK
C
OK
C
OK
Check solenoid resistance
1. Jack up the Vehicle
2. Remove the oil pan.
3. Disconnect the connector
Measure resistance between terminals 1 and 2 of sole-
noid connector.
Resistance: 5.1 ± 5.5

Check solenoid operation
Connect positive  lead with an 8±10 W bulb to terminal
1 of solenoid connector and negative  lead to terminal
2, then check the movement of the valve.
Reference
Check the 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 neg-
ative  lead to terminal 2.
3. Check the movement of the valve when the voltage is gradually increased. (A current greater than 1 A
should not be supplied.)
As the voltage is increased, the valve should move slow-
ly in the direction.
4. Check the movement of the valve when the voltage is cut off.
The valve should return in the direction.
Replace No. 4 solenoid valve.
Go to step
.
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DTC61No.2 Vehicle Speed Sensor Circuit
CIRCUIT DESCRIPTION
The No.2 speed sensor detects the rotation speed of the transmission output shaft and sends signals to the
ECM. The ECM determines the vehicle speed based on the these signals. An AC voltage i\
s generated in the
No.2 vehicle speed sensor coil as the rotor mounted on the output shaft rota\
tes, and this voltage is sent to the
ECM.
The gear shift point and lock±up timing are controlled by the ECM based \
on the signals from this vehicle speed
sensor and the throttle position sensor signal.
If the No.2 vehicle speed sensor malfunctions, the ECM uses input signals \
from the No.1 vehicle speed sensor
as a back±up signal.
DTC No.DTC Detecting ConditionTrouble Area
61
All conditions below are detected 500 times or more
continuously.
2 trip detection logic*
(a) No No.2 vehicle speed sensor signal in 4 No.1 ve-
hicle speed sensor signal pulses.
(b) Vehicle speed: 5.6 MPH (9 km/h) or more for
at least 4 secs.
(c) Park/neutral position switch:
OFF (Other than P or N position)

No. 2 vehicle speed sensor

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

ECM
*: See page AT±62
Reference

Waveform between terminals SP2+ and SP2± when vehicle speed is approx.\
37 MPH (60km/h).
AT±86
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OKNG
OKNG
INSPECTION PROCEDURE
1Check No. 1, No. 2 solenoid valves.
C
OK
P
C
P
OK
C
Electrical Check
1. Jack up the vehicle.
2. Remove oil pan.
3. Disconnect solenoid connector.
Measure resistance between solenoid connector and
body ground.
Resistance: 10 ± 16

Connect positive
lead to terminal of solenoid connec-
tor, negative  lead to solenoid body.
The solenoid makes an operating noise.
Mechanical Check
1. Remove the oil pan.
2. Remove the No. 1 and No. 2 solenoid valves.
1. Applying 490 kPa (5 kgf/cm
2, 71 psi) of compressed
air, check that the solenoid valves do not leak air.
2. When battery positive voltage is supplied to the so-
lenoid valves, check that the solenoid valves open.
Replace solenoid valve.
2Check harness and connector between ECM and solenoid (See page IN±33\
).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page AT±66). However, when diag.
trouble code 62 or 63 is displayed, check and re-
place ECM.
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OKNG
INSPECTION PROCEDURE
1Check No. 3 solenoid valve.
C
OK
P
C
OK
C
OK
C
OK
Check solenoid resistance
1. Jack up the vehicle.
2. Remove oil pan.
3. Disconnect solenoid connector.
Measure resistance between terminals 1 and 2 of sole-
noid connector.
Resistance: 3.5 ± 3.9

Check solenoid operation
Connect positive  lead with an 8 ± 10 W bulb to termi-
nal 1 of solenoid connector and negative  lead to ter-
minal 2, then check the movement of the valve.
Reference
Check solenoid operation
1. Prepare a variable power supply.
2. Connect positive  lead of the variable power sup-
ply 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 1 A
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 voltage is cut off.
The valve should return in the direction.
Replace No. 3 solenoid valve.
Go to step
.
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TORQUE SPECIFICATION
AT07F±04\
 \
Part tightened NVm kgf Vcm ft Vlbf\
 
\

\
Engine x Transmission
 

64
 

650
 

47
\
 \
Rear mounting x Body 25 260 19
\
 \
Rear mounting x Extension housing 25 250 18
\
 \
Transmission housing x Transmission case 14 mm (0.55 in.) 34 345 25
\
 \
17 mm (0.67 in.) 57 580 42
\
 \
Extension housing x Transmission case 34 345 25
\
 \
Valve body x Transmission case 10 100 7
\
 \
Oil strainer 10 100 7
\
 \
Oil pan 7.4 75 65 in.
Vlbf\
 \
No.1 vehicle speed sensor 16 160 12\
 
\

\
No.2 vehicle speed sensor 

5.4 

55 

48 in.
Vlbf
\
 \
Solenoid wiring stopper plate 5.4 55 48 in. Vlbf
\
 \
O/D direct clutch speed sensor 5.4 55 48 in. Vlbf
\
 \
Transmission output flange 123 1,250 90
\
 \
Throttle cable x Transmission case 5.4 55 48 in. Vlbf
\
 \
Union 29 300 22
\
 \
Cooler pipe union nut 34 350 25
\
 \
Drive plate x Crankshaft 99 1,000 72
\
 \
Torque converter clutch x Drive plate 33 340 25\
 \
Park/Neutral position switch Bolt 13 130 9\
 \
Nut 6.9 70 61 in. Vlbf\
 
\

\
Control shaft lever
 

16
 

160
 

12
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