1991 LEXUS SC400 Section 27 page eg 53

5. INSPECT WATER TEMPERATURE SENSORUsing an ohmmeter, measure the resistance between the ter-
minals.
Resistance: 1.48±1.58 k
at 80 5C (176 5F)
If the resistance is not as specified, replace the sensor.
6. REINSTALL WATER TEMPERATURE SENSOR (a) Install a new O±ring to the water temperature sensor.
(b) Apply soapy water to the O±ring.
(c) Install the water temperature sensor to the radiator.
Torque: 7.4 N Vm (75 kgf Vcm, 65 in. Vlbf)
(d) Connect the water temperature sensor connector.
7. REFILL WITH ENGINE COOLANT (See page CO±7)
8. REINSTALL ENGINE UNDER COVER
9. RECONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
(A/C High±Pressure Switch)
INSPECTION OF A/C HIGH±PRESSURE
SWITCH
1. DISCONNECT HIGH±PRESSURE SWITCH CONNECTOR
2. INSTALL MANIFOLD GAUGE SET (See AC section)
3. INSPECT HIGH±PRESSURE SWITCH(a) Wh e n th e A/C switch is OFF, ch e ck th a t th e re iscontinuity between terminals 2 and 3. (When the
pressure is 1,226 kPa (12.5 kgf/cm
2, 178 psi) or lower.)
(b) When the A/C switch and blower switch are ON, check
that there is no continuity between terminals 2 and 3.
(When the pressure is 1,520 kPa (15.5 kgf/cm
2, 220 psi)
or higher.)
If continuity is not as specified, replace the switch.
4. REMOVE MANIFOLD GAUGE SET
5. RECONNECT HIGH±PRESSURE SWITCH CONNECTOR
(Solenoid Valve)
(See page CO±36)
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)CO±63
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STARTER RELAY
INSPECTION OF STARTER RELAY
(See page ST±2)
1. INSPECT RELAY CONTINUITY (a) Using an ohmmeter, check that there is continuity
between terminals 1 and 2.
(b) Check that there is no continuity between terminals 3 and 5.
If continuity is not as specified, replace the relay.
2. INSPECT RELAY OPERATION (a) Apply battery voltage across terminals 1 and 2.
(b) Using an ohmmeter, check that there is continuitybetween terminals 3 and 5.
If operation is not as specified, replace the relay.
NEUTRAL START SWITCH
(See AT section)
THEFT DETERRENT SYSTEM
(See BE Section)
ST±14
±
STARTING SYSTEM Starter Relay
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GENERAL DESCRIPTION
The LEXUS SC400/300 is equipped with an SRS (Supplemental Restraint System\
) such as the driver
airbag and front passenger airbag. Failure to carry out service operations in \
the correct sequence
could cause the SRS to unexpectedly deployed during servicing, possibly leadin\
g to a serious acci-
dent. Further, if a mistake is made in servicing the supplemental restraint system, i\
t is possible the
SRS may fail to operate when required. Before performing servicing (inc\
luding removal or installa-
tion of parts, inspection or replacement), be sure to read the followin\
g items carefully, then follow
the correct procedure described in the repair manual.
1. Malfunction symptoms of the supplemental restraint system are difficult to confirm, so the diagnostic trouble codes become the most important source of information when troubleshooting. When
troubleshooting the supplemental restraint system, always inspect the diagnostic trouble codes before
disconnecting the battery (See page RS±59).
2. Work must be started after 90 seconds from the time the ignition switch turn\
ed to the LOCK position
and the negative (±) terminal cable is disconnected from the battery. (The supplemental restraint
system is equipped with a back±up power source so that if work is sta\
rted within 90 seconds of
disconnecting the negative (±) terminal cable of the battery, the SRS may be deployed.)
When the negative (±) terminal cable is disconnected from the battery, memory of the clock and audio sys-
tems will be canceled. So before starting work, make a record of the contents memo\
rized by the audio
memory system. When work is finished, reset the audio systems as before and ad\
just the clock. When the
vehicle has power tilt and power telescopic steering, power seat, power outside rear view mirror and power
shoulder belt anchorage, which are all equipped with memory function, it is not \
possible to make a record
of the memory contents. So when the work is finished, it will be necessary\
to explain this fact to the custom-
er, and ask the customer to adjust the features and reset the memory.
To avoid erasing the memory of each memory system, never use a back±up\
power supply from outside
the vehicle.
3. Even in cases of a minor collision where the SRS does not deploy, the steering wheel pad, front passenger
airbag assembly, front airbag sensors and center airbag sensor assembly should be inspe\
cted (See pages
RS±16 , 28 , 41 and 44).
4. Never use SRS parts from another vehicle. When replacing parts, replace \
them with new parts.
5. Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensors during r\
epairs.
6. Never disassemble and repair the steering wheel pad, front passenger airbag a\
ssembly, front airbag sensors or center airbag sensor assembly in order to reuse it.
7. If the steering wheel pad, front passenger airbag assembly, front airbag sensors or center airbag sensor assembly have been dropped, or if there are cracks, dents or dents or ot\
her defects in the case, bracket
or connector, replace them with new ones.
8. Do not expose the steering wheel pad, front passenger airbag assembly, front airbag sensors and center airbag sensor assembly directly to hot air or flames.
9. Use a volt/ohmmeter with high impedance (10 k
/V minimum) of troubleshooting of the system's electrical
circuit.
10. Information labels are attached to the periphery of the SRS components. \
Follow the instructions on the
notices.
11. After work on the supplemental restraint system is completed, perform the SRS\
warning light check (See page RS±59 ).
12. If the vehicle is equipped with a mobile communication system, refer to \
the precaution in the IN section. RS±2
±
SUPPLEMENTAL RESTRAINT SYSTEM GENERAL DESCRIPTION
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1. DISCONNECT NEGATIVE (±) TERMINAL CABLE FROMBATTERY
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the ªLOCKº posi-
tion and the negative (±) terminal cable is disconnected
from the battery.
(See page RS±2)
2. REMOVE ENGINE UNDER COVER
(See page BO±12)
3. REMOVE FRONT AIRBAG SENSOR
(a) Disconnect the connector.
(b) Remove the bolt, the nut and the sensor.
4. INSTALL FRONT AIRBAG SENSOR
(a) Install the sensor with the arrow on the sensor facing toward the front of the vehicle.
Torque: 25 N Vm (260 kgf Vcm, 19 ft Vlbf)
NOTICE:
w Make sure the sensor is installed to the specified torque.
w If the sensor has been dropped, or there are cracks, dents
or other defects in the case, brackets or c onnector,
replace the sensor is removed, always replace the set bolt
and the nut with new one.
w The sensor set bolt and the nut have been anti±rust
treated. When the sensor is removed, always replace the
set bolt and the nut with new ones.
w After installation, shake the sensor to check that there is
no looseness.
w The front sensor is equipped with an electrical
connection check mechanism. Be sure to lock this
mechanism securely when connecting the connector. If
the connector is not securely locked, a malfunction code
will be detected by the diagnosis system.
w Check that the dimensions of the body where the front
airbag sensor is installed match those in the body
dimension drawings in the BODY section.
(The SRS may malfunction, or may not work, if the
dimensions of the sensor mount is not correct.)
5. INSTALL ENGINE UNDER COVER
6. CONNECT NEGATIVE (±) TERMINAL CABLE TO BATTERY
±
SUPPLEMENTAL RESTRAINT SYSTEM FRONT AIRBAG SENSORRS±43
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TROUBLE SHOOTING:
Use the matrix chart below as a guide to repairs. Verify necessary inputs to the A/C Control Assembly from
the vehicle prior to disassembly. Use the repair manual, A/C system section, to validate such as B+, IL\
L+,
ground, etc.. SUSPECT AREA
SYMPTOM Control Switch Indicator Panel Control Lamp Circuit
Night Illumination does not come on
LCD back lighting does not come on
Indicator lamps of all switches are off
Indicator lamp of all switches are on
LCD is faulty
NOTE: If symptoms still exist after the suspect areas have been tested and fou\
nd not to be
faulty, replace the amplifier.
1LCD illumination bulbs are not serviceable, Control Switch must be repla\
ced if illumination
does not occur.
AIR CONDITIONING CONTROL DISASSEMBLY
:
1. Remove Air Conditioning Control Assembly.
2. Separate Control Panel from case. a. Cut the cloth tape on both sides of the case (See Fig. 2).
1992 - 1995 SC 300/400 A/C CONTROL ASSEMBLY SERVICE PARTS Page 2 of 6
Bulb Switch


1




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TSIB
IntroductionA musty odor may be emitted from the air conditioning system of some vehicles which are
usually operated in areas with high temperature and humidity. It is most noticeable when
the air conditioner is first turned ªONº after the vehicle has bee\
n parked for several hours.
The odor could result from one or more of the following conditions:
1. Blockage of the evaporator housing drain pipe, resulting in the build up of cond\
ensation.
2. Microbial growth in the evaporator, arising from dampness in the evaporator housing
where the cooling air flow is dehumidified.
To address excessive air conditioning evaporator odor, check the evaporator housing drain
pipe for blockage. If no problems are found, the evaporator and housing\
should be cleaned
and disinfected using the general procedure given on page 2, and the model \
specific
procedure on the pages indicated in the Table of Contents at the bottom of this page.
Affected While this procedure may be used on any Lexus vehicle, this bulletin giv\
es details
Vehicles specifically for the '92±'96 ES 300, all GS 300, '93±'94 LS 400, all SC 300/400 and the\
LX 450.
Tools &
PART NUMBER DESCRIPTION OF TOOLS & MATERIALS QUANTITY SOURCE
Materials08821±00810±01 Spray Gun Kit 1 OTC 08821±00811±01 Spray Gun (replacement) (1) OTC
08821±00812±01 Spray Gun Nozzle (replacement) (1) OTC
08821±00813±01 Freshener Mixing Container (replacement) (1) OTC
08821±00801±DS Air Conditioning Freshener 1 per vehicle TMS
CAUTION:
Wear safety glasses, protective mask, and gloves while working with the
freshener.
Warranty
OPCODE DESCRIPTION TIME OPN T1 T2
Information
N/A No applicable warranty information ± ± ± ±
Table ofMODEL PAGE MODEL PAGE MODEL PAGE MODEL PAGE
Contents
ES 300 3 GS 300 5 LS 400 7
GENERAL 2
SC 300 9 SC 400 9 LX 450 11
General Procedure applies to all models and model years.
The Specific Model Sections cover only the listed ªaffected models.º
HEATING & AIR CONDITIONING
September 12, 1997
Title:
AIR CONDITIONING EVAPORATOR ODOR
Models:
'92±96 ES 300, '93±'94 LS 400,
All GS 300, SC 300/400, LX 450.
Page 1 of 11
AC001±97
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AIR CONDITIONING EVAPORATOR ODOR ± AC001±97 September 12, 1997
General1. Preparation of freshener solution:
Procedure (a) Invert freshener container and shake vigorously for 30 seconds.
(b) Mix 3.4 fl. oz. of freshener (1 container) with 30 fl. oz. to make 1 q\
t. of solution.
2. Drying the evaporator: Dry the evaporator for 10 minutes with the following settings:
A/C: Off
. . . . . . . . . . .
Air Outlet: Foot
. . . . . .
Mode: Recirc.
. . . . . . . . . .
Blower: High
. . . . . . . .
Te m p : Max Warm
. . . . . . . . . .
3. Evaporator Treatment Preparation: (a) Ensure availability of 30±45 psi compressed air to be used with spray\
gun for application of freshener.
(b) Place a tray under the evaporator housing drain hose to collect used cle\
aning solution.
(c) Place shop cloth under the evaporator housing in the vehicle to prevent \
cleaning solution from dripping onto the floor mat.
4. Vehicle Preparation: See specific model section.
5. Evaporator treatment: (a) Set HVAC mode as follows: A/C: Off
. . . . . . . . . . .
Air Outlet: Face
. . . . . .
Mode: Fresh
. . . . . . . . . .
Blower: High
. . . . . . . .
Te m p : Max Warm
. . . . . . . . . .
Windows: Open
. . . . . .
(b) Insert spray nozzle into the filter inlet and spray the entire quantity (1 qt.) of
freshener solution into the evaporator
while moving the nozzle around to
cover the complete evaporator surface.
(c) Turn the blower OFF.
6. Reinstallation of Parts.
7. Completion of Treatment. (a) Dry the evaporator for 30 minutes with the following settings:
A/C: Off
. . . . . . . . . . .
Air Outlet: Foot
. . . . . .
Mode: Recirc.
. . . . . . . . . .
Blower: High
. . . . . . . .
Te m p : Max Warm
. . . . . . . . . .
Windows: Closed
. . . . . .
(b) If the vehicle still has alcohol smell, open windows for ventilation. Do not turn on
the AC switch until the evaporator is
completely dry as this can reduce the
effectiveness of the solution.
Page 2 of 11
CAUTION
Do not get into the vehicle during
this drying operation.
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A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
5
:System Title
: Indicates a Relay Block. No shading is used and only
the Relay Block No. is shown to distinguish it from the
J/B.
Example: Indicates Relay Block No. 1.
: Indicates the connector to be connected to a part (the
numeral indicates the pin No.)
Explanation of pin use.
The pins shown are only for the highest grade, or only
include those in the specification.
: Connector Color
Connectors not indicated are milky white in color.
: ( ) is used to indicate different wiring and connector,
etc. when the vehicle model, engine type, or
specification is different.
: Indicates related system.
: Indicates the wiring harness and wiring harness
connector. The wiring harness with male terminal is
shown with arrows ( ).
Outside numerals are pin numbers.
The first letter of the code for each wiring harness and
wiring harness connector(s) indicates the component's
location, e.g., ªEº for the Engine Compartment, ªIº for the
Instrument Panel and Surrounding area, and ªBº for the
Body and Surrounding area.
When more than one code has the first and second
letters in comm on, followed by numbers (e.g., IH1, IH2),
this indicates the same type of wiring harness and
wiring harness connector.
: Represents a part (all parts are shown in sky blue). The
code is the same as the code used in parts position.
: Junction Block (The number in the circle is the J/B No.
and the connector code is shown beside it). Junction
Blocks are shaded to clearly separate them from other
parts (different j unction blocks are shaded differently for
further clarification).
3B indicates
that it is inside
Junction Block
No. 3.
Example: :
Indicates the wiring color.
Wire colors are indicated by an alphabetical code.
B = Black L = Blue R = Red
BR = Brown LG = Light Green V = Violet
G = Green O = Orange W = White
GR = Gray P = Pink Y = Yellow
The first letter indicates the basic wire color and the
second letter indicates the color of the stripe.
Example: L ± Y
(Blue) (Yellow)
:Indicates a wiring Splice Point (Codes are ªEº for the
Engine Room, ªIº for the Instrument Panel, and ªBº for
the Body).
Example:
The Location of Splice Point I 5 is indicated by the
shaded section.
: Page No.
: Indicates a shielded cable.
:Indicates a ground point.
The first letter of the code for each ground point(s)
indicates the component's location, e.g., ªEº for the
Engine Compartment, ªIº for the Instrument Panel and
Surrounding area, and ªBº for the Body and
Surrounding area.
: Indicates the pin number of the connector.
The numbering system is different for female and male
connectors.
Example: Numbered in order from upper left to
lower right Numbered in order
from upper right to
lower left
:
When 2 parts both use one connector in common, the
parts connector name used in the wire routing section
is shown in square brackets [ ].
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