low oil pressure TOYOTA SUPRA 1995 Service User Guide

HYDRAULIC CONTROL SYSTEM
The hydraulic control system is composed of the oil pump, the valve body, the solenoid valves and the
clutches and brakes, as well as the fluid passages which connect all of these components. Based on the
hydraulic pressure created by the oil pump, the hydraulic control system governs the hydraulic pressure
acting on the torque converter clutch, clutches and brakes in accordance with the vehicle driving condi-
tions.
There are three solenoid valves on the valve body. These solenoid valves are turned on and off by signals
from the ECM to operate the shift valves. These shift valves then switch the fluid passages so that fluid
goes to the torque converter clutch and planetary gear units.
Except for the solenoid valves, the hydraulic control system of the electronically controlled transmission
is basically the same as that of the fully hydraulic controlled automatic transmission.
HYDRAULIC CONTROL SYSTEM
VALVE BODY
OIL PUMP
ECMSOLENOID VALVES
CLUTCHES & BRAKES
Hydr. pressure control
Fluid passage switchingPlanetary gear sets
Torque Converter Clutch
w LINE PRESSURE
Line pressure is the most basic and important pressure used in the automatic transmission, because it is
used to operate all of the clutches and brakes in the transmission.
If the primary regulator valve does not operate correctly, line pressure will be either too high or too low. Line
pressure that is too high will lead to shifting shock and consequent engine power loss due to the greater
output required from the oil pump; line pressure that is too low will cause slippage of clutches and brakes,
which will, in extreme cases, prevent the vehicle from moving. Therefore, if either of these problems are
noted, the line pressure should be measured to see if it is within standard.
w THROTTLE PRESSURE
Throttle pressure is always kept in accordance with the opening angle of the engine throttle valve. This
throttle pressure acts on the primary regulator valve and, accordingly, line pressure is regulated in re-
sponse to the throttle valve opening.
In the fully hydraulic controlled automatic transmission, throttle pressure is used for regulating line pressure
and as signal pressure for up±shift and down±shift of the transmission. In the electronically controlled
transmission, however, throttle pressure is used only for regulating line pressure. Consequently, improper
adjustment of the transmission throttle cable may result in a line pressure that is too high or too low. This,
in turn, will lead to shifting shock or clutch and brake slippage. AT1±6
± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONOPERATION

09032±00100 Oil Pan Seal Cutter
09308±10010 Oil Seal Puller
09325±40010 Transmission Oil Plug
09350±30020 TOYTOA Automatic Transmission
Tool Set
(09351±32010) One±way Clutch Test Tool
(09351±32020) Stator Stopper
09843±18020 Diagnosis Check Wire
09990±01000 Engine Control Computer Check
Harness ªAº
09992±00094 Automatic Transmission Oil
Pressure Gauge Set
PRECAUTION
PRECAUTIONS
When working with FIPG material, you must observe the following.
wUsing a razor blade and gasket scraper, remove all the old packing (FIPG) material from the
gasket surfaces.
wThoroughly clean all components to remove all the loose material.
wClean both sealing surfaces with a non±residue solvent.
wApply the seal packing in an approx. 1 mm (0.04 in.) bead along the sealing surface.
wParts must be assembled within 10 minutes of application. Otherwise, the packing (FIPG)
material must be removed and reapplied.
If the vehicle is equipped with a mobile communication system, refer to the precaution in the IN sec-
tion.
PREPARATION
SST (SPECIAL SERVICE TOOLS)
AT1±12± AT340E (2JZ±GE) AUTOMATIC TRANSMISSIONPRECAUTION

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

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

WARNING LIGHTS
 Trouble Parts name (See page)
 
 
 
 
 
Warning lights do not light up
(Except Discharge and Door Open)
 
 
 
 
 
1. Bulb
2. IGN Fuse (BE±6)
3. Ignition Switch (BE±8)
4. Meter Circuit Plate (BE±44)
5. Wire Harness
6. Generator
 
 
 
 
 
 
Brake Warning Light does not light up
 
 
 
 
 
 
1. Bulb
2. Brake Fluid Level Warning Switch (BE±52)
3. Parking Brake Switch (BE±52)
4. Bulb Check Relay
5. Meter Circuit Plate (BE±44)
6. Wire Harness
 
 
 
 
 
Seat Belt Warning Light does not light up
 
 
 
 
 
1. Bulb
2. Seat Belt Buckle Switch (BE±56)
3. Integration Relay (BE±55)
4. Meter Circuit Plate (BE±44)
5. Wire Harness
 
 
 
 
Engine Oil Level Warning Light does not light up
 
 
 
 
1. Bulb
2. Engine Oil Level Switch (BE±51)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
Low Oil Pressure Warning Light does not light up
 
 
 
1. Bulb
2. Low Oil Pressure Warning Switch (BE±51)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
 
 
 
 
 
 
 
Door Open Warning Light does not light up
 
 
 
 
 
 
 
1. Bulb
2. DOME Fuse (BE±5)
3. Door Courtesy Switch (BE±54)
4. Luggage Room Light Switch (BE±28)
5. Integration Relay
6. Meter Circuit Plate (BE±44)
7. Wire Harness
 
 
 
 
Master Warning Light does not light up
 
 
 
 
1. Bulb
2. Telltale Light (BE±48)
3. Meter Circuit Plate (BE±44)
4. Wire Harness
BE±42± BODY ELECTRICAL SYSTEMCOMBINATION METER

LOW OIL PRESSURE WARNING
INSPECTION
1. INSPECT SWITCH
(a) Check that there is continuity between terminal and ground
with the engine stopped.
(b) Check that there is no continuity between terminal and
ground with the engine running.
HINT: Oil pressure should be over 29 kPa (0.3 kgf/ cm
2, 4.3
psi)
If operation is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the warning switch and
ground terminal on the wire harness side connector.
(b) Turn the ignition switch ON, check that the warning light lights
up.
If the warning light does not light up, test the bulb or inspect
wire harness.
ENGINE OIL LEVEL WARNING
INSPECTION
1. INSPECT SWITCH
(a) Check that there is continuity between terminal with the
switch in each position.
(b) Heat the switch to above 60°C (140°F) in an oil bath.
(c) Check that there is continuity between terminals with the
switch ON (float up).
(d) Check that there is no continuity between terminals with the
switch OFF (float down).
If operation is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the switch.
(b) Ground terminal 1 on the wire harness connector.
(c) Turn the ignition switch ON. Check that the warning light
lights up approximately 40 seconds later.
If the warning light does not light up, inspect bulb or wire har-
ness.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±51

BACK DOOR DAMPER STAY REMOVAL
1. REMOVE ROOF SIDE INNER GARNISH
(See page BO±60)
2. REMOVE DAMPER STAY LOWER END FROM BODY
3. REMOVE DAMPER STAY UPPER END FROM BACK
DOOR
NOTICE: When handling the damper.
wDo not disassemble the damper because the cylinder is
filled with pressurized gas.
wIf the damper is to be replaced, drill a 2.0±3.0 mm
(0.079±0.118 in.) hole in the bottom of the removed
damper cylinder to completely release the high±pressure
gas before disposing of it.
wWhen drilling, chips may fly out so work carefully.
wThe gas is colorless, odorless and non±toxic.
wWhen working, handle the damper carefully. Never score
or scratch the exposed part of the piston rod, and never
allow paint or oil to get on it.
wDo not turn the piston rod and cylinder with the damper
fully extended.
BACK DOOR DAMPER STAY
INSTALLATION
1. INSTALL DAMPER STAY UPPER END TO BACK DOOR
NOTICE: Apply adhesive to the bolts before tightening.
Nut to body
Torque: 5.9 NVm (60 kgfVcm, 52 in.Vlbf)
Bolt to back door
Torque: 7.8 NVm (80 kgfVcm, 69 in.Vlbf)
2. INSTALL DAMPER STAY LOWER END TO BODY
3. INSTALL ROOF SIDE INNER GARNISH
(See page BO±60) BO±18
± BODYBACK DOOR

TROUBLESHOOTING
Use the table below to help you find the cause of the problem. The numbers indicate the priority of the likely
cause of the problem. Check each part in order. If necessary, replace these parts.
CL±4CL±6CL±11See page
Parts Name
Trouble
Clutch grabs/chatters
Clutch noisy
Clutch slips
Clutch pedal spongy
Clutch does not disengage
Clutch pedal (freeplay out of adjustment)Pilot bearing (Worn or damaged)Release bearing (Worn, dirty or damaged)Engine mounting (loosen)Release cylinder cup (Damaged)master cylinder cup (Damaged)Clutch line (Air in line)Clutch disc (Dirty or burred)Clutch disc (Oily)Clutch disc (Worn out)Clutch disc torsion rubber (Damaged)Clutch disc (Out of true)Input shaft bearing (Worn or damaged)Clutch disc (Lining broken)Clutch disc (Runout is excessive)Clutch disc (Lack of spline grease)Diaphragm spring (Damaged)Clutch disc (Glazed)Diaphragm spring (Out of tip alignment)Pressure plate (Distortion)Flywheel (Distortion)
CL±17CL±8CL±9CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±11CL±17CL±15CL±21CL±11CL±17CL±15CL±20CL±11CL±17
± CLUTCHTROUBLESHOOTINGCL±3

COOLANT CHECK
1. CHECK ENGINE COOLANT LEVEL AT RADIATOR
RESERVOIR
The engine coolant level should be between the ºLOWº and
ºFULLº lines.
If low, check for leaks and add engine coolant up to the
ºFULLº line.
2. CHECK ENGINE COOLANT QUALITY
(a) Remove the radiator cap.
CAUTION: To avoid the danger of being burned, do not remove
the radiator cap while the engine and radiator are still hot, as
fluid and steam can be blown out under pressure.
(b) There should not be any excessive deposits of rust or scale
around the radiator cap or radiator filler hole, and the coolant
should be free from oil.
If excessively dirty, replace the coolant.
(c) Reinstall the radiator cap. EG±330
± ENGINECOOLING SYSTEM

SERVICE SPECIFICATIONS
SERVICE DATA
 
 
Thermostat 
 
Valve opening temperature
Valve lift at 95°C (203°F) 
 
80±84°C (176±183°F)
8.5 mm (0.335 in.) or more
 
 
 
Radiator cap 
 
 
Relief valve opening pressure STD
Minimum 
 
 
93±123 kPa
(0.95±1.25 kgf/cm2, 13.5±17.8 psi)
78 kPa (0.8 kgf/cm
2, 11.4 psi)
 
 
Electric
cooling fan 
 
Rotating amperage 
 
2.5±4.5 A
TORQUE SPECIFICATIONS
 Part tightened NVm kgfVcm ftVlbf
 Engine drain plug x Cylinder block 29 300 22
 Fan x Fluid coupling 7.4 75 65 in.Vlbf
 Water pump x Cylinder block 21 210 15
 Water pump x No.2 water bypass pipe 21 210 15
 Generator x Water pump 37 380 27
 Generator x Cylinder block 37 380 27
 Water bypass outlet x Cylinder head (2JZ±GE) 8.8 90 78 in.Vlbf
 Water outlet x Cylinder head (2JZ±GTE) 21 210 15
 Water inlet x Water pump (2JZ±GE) 8.8 90 78 in.Vlbf
 Water inlet x Water pump (2JZ±GTE) 21 210 15 Upper radiator support x Body 15 155 11 ECT switch x Radiator (2JZ±GTE) 7.4 75 65 in.Vlbf Fluid coupling x Water pump 16 165 12 Oil cooler x Radiator lower tank (A/T) 8.3 85 74 in.Vlbf Oil cooler x Oil cooler pipe (A/T) 15 150 11
EG±358± ENGINECOOLING SYSTEM