LEXUS SC400 1991 Service Repair Manual

SOLAR SENSOR
REMOVAL OF SOLAR SENSOR
1. REMOVE NO. 1 DEFROSTER GARNISHSee page BO±109
2. REMOVE SENSOR Push out the sensor from the garnish.
INSPECTION OF SOLAR SENSOR
See page AC±52
INSTALLATION OF SOLAR SENSOR
1. INSTALL SENSOR TO NO. 1 DEFROSTER GARNISH
2. INSTALL NO. 2 DEFROSTER GARNISH
See page BO±109
EVAPORATOR TEMPERATURE
SENSOR
REMOVAL OF EVAPORATOR
TEMPERATURE SENSOR
1. REMOVE EVAPORATOR
See page AC±122
2. REMOVE SENSOR FROM EVAPORATOR
INSPECTION OF EVAPORATOR
TEMPERATURE SENSOR
See page AC±48
INSTATION OF EVAPORATOR
TEMPERATURE SENSOR
1. INSTALL SENSOR TO EVAPORATOR
2. INSTALL EVAPORATOR
See page AC±124
AC±134
±
AIR CONDITIONING SYSTEM Solar Sensor, Evaporator Temperature Sensor
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REVOLUTION DETECTING SENSOR
INSPECTION OF REVOLUTION
DETECTING SENSOR
See page AC±55
REMOVAL OF REVOLUTION DETECTING
SENSOR
1. REMOVE COMPRESSOR
See page AC±111
2. REMOVE SENSOR Remove the two bolts and the sensor.
INSTALLATION OF REVOLUTION
DETECTING SENSOR
1. INSTALL SENSORUsing a torque wrench, tighten the bolts.
Specified Torque: 6 N Vm (60 kgf Vcm, 4 ft Vlbf)
2. INSTALL COMPRESSOR
See page AC±117
±
AIR CONDITIONING SYSTEM Revolution Detecting SensorAC±135
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WATER TEMPERATURE SENSOR
REMOVAL OF WATER TEMPERATURE
SENSOR
1. REMOVE A/C UNITSee page AC±107
2. REMOVE SENSOR After taking off the clamp, take out the sensor.
INSPECTION OF WATER TEMPERATURE
SENSOR
See page AC±51
INSTALLATION OF WATER
TEMPERATURE SENSOR
1. INSTALL SENSOR TO A/C UNIT
Install the sensor with the clamp.
2. INSTALL A/C UNIT See page AC±108
PRESSURE SWITCH
INSPECTION OF PRESSURE SWITCH
See page AC±57
REMOVAL OF PRESSURE SWITCH
1. RECOVER REFRIGERANT IN REFRIGERANT SYSTEM
See page AC±16
2. REMOVE PRESSURE SWITCH
(a) Disconnect the connector.
(b) Remove the pressure switch from the liquid tube. HINT: Lock the switch mount on the tube with an open end
wrench, being careful not to deform the tube, and remove the
switch.
AC±136
±
AIR CONDITIONING SYSTEM Water Temperature Sensor, Pressure Switch
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INSTALLATION OF PRESSURE SWITCH
1. INSTALL PRESSURE SWITCH
(a) Install the pressure switch to the liquid tube.
Specified torque: 10 NVm (100 kgf Vcm, 7 ft Vlbf)
HINT: Lock the switch mount on the tube with an open end
wrench, being careful not to deform the tube, and install the
switch.
(b) Connect the connector.
2. EVACUATE AIR IN REFRIGERATION SYSTEM AND CHARGE WITH REFRIGERANT
See page AC±17
Specified amount: 950 + 50 g (33.44 + 1.76 oz)
3. INSPECTION FOR LEAKAGE OF REFRIGERANT
Using a gas lead tester, check for leakage of refrigerant from
the pressure switch mount.
4. INSPECT A/C OPERATION
POWER TRANSISTOR
REMOVAL OF POWER TRANSISTOR
1. REMOVE GLOVE BOX
2. REMOVE POWER TRANSISTOR
(a) Disconnect connectors.
(b) Remove the two screws and the power transistor.
INSPECTION OF POWER TRANSISTOR
See page AC±79
INSTALLATION OF POWER
TRANSISTOR
1. INSTALL POWER TRANSISTOR
(a) Install power transistor with two screws.
(b) Connect connectors.
2. INSTALL GLOVE BOX
See page BO±112
±
AIR CONDITIONING SYSTEM Pressure Switch, Power TransistorAC±137
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INSTALLATION OF PRESSURE SWITCH
1. INSTALL PRESSURE SWITCH
(a) Install the pressure switch to the liquid tube.
Specified torque: 10 NVm (100 kgf Vcm, 7 ft Vlbf)
HINT: Lock the switch mount on the tube with an open end
wrench, being careful not to deform the tube, and install the
switch.
(b) Connect the connector.
2. EVACUATE AIR IN REFRIGERATION SYSTEM AND CHARGE WITH REFRIGERANT
See page AC±17
Specified amount: 950 + 50 g (33.44 + 1.76 oz)
3. INSPECTION FOR LEAKAGE OF REFRIGERANT
Using a gas lead tester, check for leakage of refrigerant from
the pressure switch mount.
4. INSPECT A/C OPERATION
POWER TRANSISTOR
REMOVAL OF POWER TRANSISTOR
1. REMOVE GLOVE BOX
2. REMOVE POWER TRANSISTOR
(a) Disconnect connectors.
(b) Remove the two screws and the power transistor.
INSPECTION OF POWER TRANSISTOR
See page AC±79
INSTALLATION OF POWER
TRANSISTOR
1. INSTALL POWER TRANSISTOR
(a) Install power transistor with two screws.
(b) Connect connectors.
2. INSTALL GLOVE BOX
See page BO±112
±
AIR CONDITIONING SYSTEM Pressure Switch, Power TransistorAC±137
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A/C CONTROL ASSEMBLY
(A/C ECU)
REMOVAL OF A/C CONTROL ASSEMBLY
1. REMOVE RADIO AND A/C CONTROL ASSEMBLYSee page BO±112
2. REMOVE A/C CONTROL ASSEMBLY Remove four screws and the A/C control assembly.
INSPECTION OF A/C CONTROL
ASSEMBLY
Judge whether the system is satisfactory or not based on the
ºTroubleshootingº procedure on page AC±21.
INSTALLATION OF A/C CONTROL
ASSEMBLY
1. INSTALL A/C CONTROL ASSEMBLY TO RADIO
Install the A/C control assembly to the radio with four screws.
2. INSTALL RADIO AND A/C CONTROL ASSEMBLY See page BO±112
AC±138
±
AIR CONDITIONING SYSTEM A/C Control Assembly (A/C ECU)
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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
±
AIR CONDITIONING SYSTEM Service SpecificationsAC±139
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Diag. Code 14\
 \
Open in Squib Circuit
DIAGNOSTIC CHARTDIAGNOSTIC CHART
The squib circuit consists of the center airbag sensor assembly, spiral cable and the steering wheel pad
(squib). It causes the airbag to deploy when the airbag deployment con\
ditions are satisfied.
For details of the function of each component, see FUNCTION OF COMPONENT\
S on page AB±5.
Diagnostic code 14 is recorded when an open is detected in the squib cir\
cuit.
 Code No.\
 \
Diagnosis
 



14
\
 
\


\

\


Open circuit in D+ wire harness or D wire harness of squib.
 Squib malfunction.
 Spiral cable malfunction.
 Center airbag sensor assembly malfunction.
AB±62±
SRS AIRBAG Troubleshooting
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Preperation.
Check squib circuit.
Check spiral cable.Check harness between center airbag
sensor assembly and spiral cable.
Check center airbag sensor assembly.
Check squib.
From the results of the above inspection, the
malfunctioning part can now be considered
normal. To make sure of this, use the simula-
tion method to check. Go to step
Repair or replace spiral cable.
Repair or replace harness or con-
nector between center airbag sen-
sor assembly and spiral cable. Replace center airbag
sensor assembly
Replace steering wheel pad.
WIRING DIAGRAM
DIAGNOSTIC CHARTDIAGNOSTIC CHART
±
SRS AIRBAG TroubleshootingAB±63
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INSPECTION PROCEDURE
(1) Disconnect battery negative (±) terminal cable, and wait at least 20 seconds.
(2) Remove steering wheel pad (See page AB±14).
Measure resistance between D+ and D± on spiral
cable side of connector between spiral cable and
steering wheel pad.
Preparation.
Resistance: Below 1

When storing steering wheel pad, keep upper sur-
face fo the pad facing upward.
Disconnect center airbag sensor assembly connec-
tor.
Check squib circuit.
Go to step
AB±64±
SRS AIRBAG Troubleshooting
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