1991 LEXUS SC400 engine

COMPRESSOR
INSPECTION OF COMPRESSOR
(Magnetic Clutch)
See page AC±86
(Compressor)
1. INSTALL MANIFOLD GAUGE SET
See page AC±15
2. START ENGINE
3. INSPECT COMPRESSOR FOR METALLIC SOUND Check that there is metallic sound from the compressor when
the A/C switch is turned on.
If a metallic sound is heard, replace the compressor assem-
bly.
4. INSPECT PRESSURE OF REFRIGERATION SYSTEM See ºInspection of Refrigeration System with Manifold
Gauge Setº on page.
5. STOP ENGINE
6. INSPECT VISUALLY FOR LEAKAGE OF REFRIGERANT FROM SAFETY SEAL
If there is any leakage, replace the compressor assembly.
AC±110
±
AIR CONDITIONING SYSTEM Troubleshooting
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REMOVAL OF COMPRESSOR
1. RUN ENGINE AT IDLE SPEED WITH A/C ON FORAPPROX. TEN MINUTES
2. STOP ENGINE
3. DISCONNECT NEGATIVE (±) CABLE FROM BATTERY
4. RECOVER REFRIGERANT FROM REFRIGERATION
SYSTEM
5. DISCONNECT DISCHARGE HOSE AND SUCTION HOSE
FROM COMPRESSOR
NOTICE: Cap the open fittings immediately to keep mois-
ture out of the system.
6. DISCONNECT CONNECTOR FROM MAGNETIC CLUTCH
7. REMOVE DRIVE BELT
See step 6 on page EM±118.
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AIR CONDITIONING SYSTEM CompressorAC±111
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EXPANSION VALVE
ON±VEHICLE INSPECTION
1. CHECK QUANTITY OF GAS DURING REFRIGERATIONCYCLE
2. INSTALL MANIFOLD GAUGE SET
3. RUN ENGINE
Run the engine at 2,000 rpm for at least 5 minutes. Then
check that the high pressure reading is 1,275±1,471 kPa
(13±15 kgf/cm, 185±213 psi).
4. CHECK EXPANSION VALVE If the expansion valve is faulty, the low pressure reading will
drop to 0 kPa (0 kgf/cm, 0 psi), otherwise it is OK.
HINT: When the low pressure drops to 0 kPa (0 kgf/cm, 0 psi),
feel the receiver's IN and OUT sides for no temperature differ-
ence.
REMOVAL OF EXPANSION VALVE
1. REMOVE EVAPORATOR See page AC±124.
2. REMOVE EQUALIZER TUBES
3. REMOVE EXPANSION VALVE
INSTALLATION OF EXPANSION VALVE
1. INSTALL EXPANSION VALVE
Specified torque:
0.31 inch tube 13 N Vm (135 kgf Vcm, 10 ft Vlbf)
0.50 inch tube 22 N Vm (225 kgf Vcm, 16 ft Vlbf)
2. INSTALL EQUALIZER TUBES
3. INSTALL EVAPORATOR
See page AC±124
AC±126
±
AIR CONDITIONING SYSTEM Expansion Valve
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AMBIENT TEMPERATURE SENSOR
REMOVAL OF AMBIENT TEMPERATURE
SENSOR
1. REMOVE ENGINE UNDER COVER
2. REMOVE SENSOR
(a) Remove the clip and the sensor.
(b) Disconnect the connector.
INSPECTION OF AMBIENT
TEMPERATURE SENSOR
See page AC±46
INSTALLATION OF AMBIENT
TEMPERATURE SENSOR
1. INSTALL SENSOR
(a) Connect the connector.
(b) Install the sensor with the clip.
2. INSTALL ENGINE UNDER COVER
±
AIR CONDITIONING SYSTEM Ambient Temperature SensorAC±133
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SERVICE SPECIFICATIONS
SERVICE DATA
Idle speed Magnetic clutch no engaged
Magnetic clutch engaged
Magnetic clutch clearanceApprox. 700 rpm
Approx. 700 rpm
0.5 + 0.15 mm 0.020 + 0.006 in.
TORQUE SPECIFICATIONS
Part tightenedN Vmkgf Vcmft Vlbf
Suction hose X Compressor2525018
Discharge hose X Compressor25250 18
Compressor X EngineBolt 49500 36
Nut 29300 22
Liquid tube X Receiver10 55 7
Liquid tube X Condenser10100 7
Discharge tube X Condenser10100 7
Expansion valve X Evaporator 5.4 55 48 in. Vlbf
Suction tube X A/C Unit10100 7
Liquid tube X A/C Unit10100 7
Equalizer tube X EPR25250 18
Pressure switch X Liquid tube10100 7
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AIR CONDITIONING SYSTEM Service SpecificationsAC±139
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LOCATION OF CONNECTORS IN ENGINE COMPARTMENT
AB±38SRS AIRBAG ± Troubleshooting
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(1) Turn ignition switch LOCK.
(2) Disconnect center airbag sensor assemblyconnector.
(3) Turn ignition switch ON. But do not start engine.
(4) Measure voltage at IG
2 or ACC on connector
wire harness side of center airbag assembly and
operate electric system (defogger, wiper,
headlight, heater, blower, etc.).
Voltage: 6 V ± 11.5 V at IG
2 and ACC.
(5) Turn electric system switch OFF.
(6) Turn ignition switch LOCK.
(7) Remove voltmeter and connect center airbag sensor assembly.
Does airbag warning light turn off after approx. 10 seconds?
Preparation.
Turn ignition switch ON.
Operate electric system checked in [ 1 ] (4) and
check that airbag warning light goes off after
approx. 10 seconds.
Check diagnostic code, and if a malfunction
code is output, perform troubleshooting
according to malfunction code. If a normal
code is output, replace center airbag
sensor assembly.
Check battery and charging system
(See page CH±1)
INSPECTION PROCEDURE
AB±41SRS AIRBAG ± Troubleshooting
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DIAGNOSIS SYSTEM
AT09R±07
The electronically controlled transmission system has built±
in self±diagnostic functions. If the malfunction occurs in the
system, the ECM stores the malfunction code in memory and
the O/D OFF (Overdrive OFF) indicator light blinks to inform
the driver. The diagnostic trouble code stored in memory can
be read out by the following procedure.
O/D OFF INDICATOR LIGHT INSPECTION
AT09S±07
1. Turn the ignition switch to ON.
2. Check if the O/D OFF indicator light lights up when the O/D main switch is pushed out to OFF and goes off when
the O/D main switch is pushed in to ON.
HINT:
wIf the O/D OFF indicator light does not light up or stay on
all the time, carry out the check for ªO/D OFF Indicator
Light Circuitº on page AT±112.
w If the O/D OFF indicator light blinks, a trouble code is
stored in the ECM memory.
DIAGNOSTIC TROUBLE CODE CHECK
AT0A3±07
1. Turn the ignition switch ON, but do not start the engine.
2. Push in the O/D main switch to ON.
HINT: Warning and diagnostic trouble codes can be r ead only
when the O/D main switch is ON. If it is OFF, the O/D OFF indi-
cator lights up continuously and will not blink.
3. Using SST, connect terminals TE1 and E1 of the DLC2 or
DLC1.
SST 09843±18020
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±37
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