engine LEXUS SC400 1991 Service Service Manual

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
WhereEverybodyKnowsYourName

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.
±
AIR CONDITIONING SYSTEM CompressorAC±111
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

LOCATION OF CONNECTORS IN ENGINE COMPARTMENT
AB±38SRS AIRBAG ± Troubleshooting
WhereEverybodyKnowsYourName

(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
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

CHECK TERMINAL TT OUTPUT
VOLTAGE
AT00R±01
When a voltmeter is connected to the DLC1, the following
items can be checked.
1. Throttle position sensor signal
2. Brake signal
3. Shift position signal
1. VOLTMETER CONNECTION Connect the positive (+) probe of the voltmeter to terminal T
T
and the negative (±) probe to terminal E1 of the DLC2.
HINT: If a voltmeter with small internal resistance is used, the
correct voltage will not be indicated, so use a voltmeter with
an internal resistance of at least 10 k
.
2. TURN IGNITION SWITCH TO ON (DO NOT START THE
ENGINE)
3. CHECK THROTTLE POSITION SENSOR SIGNAL Check if the voltage changes from approximately 0 V to
approximately 8 V when the accelerator pedal is gradually
depressed from the fully closed position.
4. CHECK BRAKE SIGNAL (LOCK±UP CUT SIGNAL)
(a) Open the throttle valve fully to apply approximately 8 V to terminal T
T.
(b) In this condition, check terminal T
T voltage when the brake
pedal is depressed and released.
TT terminal voltage:
0 V (When brake pedal is depressed)
8 V (When brake pedal is released)
5. START ENGINE
6. CHECK SHIFT POSITION SIGNAL (VEHICLE SPEED ABOVE 60 KM/H OR 37 MPH)
Check up±shifting together with terminal T
T voltage.
HINT: Check for light shocks from up±shifting and for
changes in the tachometer.
 Gear Position Terminal TT output voltage 1st GearBelow 0.5 V 

2nd Gear1.5 ~
2 6 V
 3rd Gear3.5 ~ 4.6 V
 3rd Lock±up4.5 ~ 5.9 V
 O/D5.5 ~ 6.9 V
 O/D Lock±up6.5 ~ 7.9 V
If terminal TT output voltage check cannot be performed, per-
form the check of terminal T
T circuit on page AT±120.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±39
WhereEverybodyKnowsYourName

PROBLEM SYMPTOM CONFIRMATION
AT09U±07
Taking into consideration the results of the customer problem analysis, try to\
reproduce the symptoms of
the trouble. If the problem is that the transmission does not up±shift, \
does not down±shift, or the shift point
is too high or too low, conduct the following road test referring to the automatic shift schedu\
le and simulate
the problem symptoms.
ROAD TEST
AT09V±05NOTICE: Perform the test at normal ATF operating temperature
50±80 5C (122±176 5F).
1. D POSITION TEST (NORM AND PWR PATTERN)
Shift into the D position and fully depress the accelerator ped-
al and check the following points:
(a) Check up±shift operation
1" 2, 2 "3 and 3 "O/D up±shift takes place, and shift point
should conform to those shown in the automatic shift sched-
ule (See page AT±45)
Conduct a test under both Normal and Power patterns.
HINT:
w O/D up±shift or lock±up will not occur when the engine
coolant temp. is below 60
C (140
F) and speed is under
60 km/h (37 mph), or if there is a 10 km/h (6 mph)
difference between the set cruise control speed.
w 3rd up±shift or lock±up will not occur when engine
coolant temp. is below 35
C (95
F) and speed is under
40 km/h (25 mph).
(b) Check for shift shock and slip. In the same manner, check the shock and slip at the 1 "2,
2 " 3 and 3 "O/D up±shifts.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±41
WhereEverybodyKnowsYourName