1991 LEXUS SC400 ECO mode

ALTERNATE REFRIGERANTS AND A/C RETROFITPage 2 of 2
RETROFIT ISSUES:
Lexus has completed development of retrofit parts for all later model Le\
xus vehicles using R±12 refrigerant.
These parts will be produced in harmony with market demand, based on R±12 \
availability.
The parts necessary for a typical retrofit will generally include:Receiver Dryer
O±Rings
Fittings
Labels
Oil
A TSIB outlining retrofit procedures will be released when the retrofit \
kits become available.
For additional information, contact the Environmental Assistance Network\
Hotline at 1±800±542±3914.
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A
B
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F
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J
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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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Junction Block (the number in the circle is the
J/B No. and connector code is shown beside
it). Junction Blocks are shaded to clearly
separate them from other parts (different
junction blocks are shaded differently for fur-
ther clarification.).
Example:
Indicates related system.
Indicates the wiring harness and wiring har-
ness connector. The wiring harness with male
terminal is shown with arrows
Outside numerals are pin numbers.
is used to indicate different wiring and
connector, etc. when the vehicle model, engine
type, or specification is different.
Indicates a shielder cable.
Indicates and located on ground point.
The same code occuring on the next page
indicates that the wire harness is continuous.
System Title
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.
Indicates the connector to be connected to a
part (the numeral indicates the pin No.)
The position of the parts. is the same as shown
in the wiring diagram and wire routing.
Indicates the pin number of the connector.
The numbering system is different for female
and male connectors.
The numbering system for the overall wiring
diagram is the same as above.
Indicates a Relay Block. No Shading is used
and only the Relay Block No. is shown to distin-
guish it from the J/B.
243
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177
SRS AIRBAG
NOTICE: When inspecting or repairing the SRS AIRBAG, perform the operation in accord\
ance with the
following precautionary instructions and the procedure and precautions in the Repair Manual for the applicable
model year.

Malfunction symptoms of the airbag system are difficult to confirm, so the diagnostic codes become the most
important source of information when troubleshooting.
When troubleshooting the airbag system, always inspect the diagnostic codes before disconnecting the
battery.

Work must be started after 30 seconds or longer from the time the Ignition SW is set to the ªLOCKº position
and the negative (±) terminal cable is disconnected from the battery.
(The airbag system is equipped with a back±up power source so that if work is started within 30 seconds of
disconnecting the negative (±) terminal cable of the battery, the airbag may be deployed.)
When the negative (±) terminal cable is disconnected from the battery, memory of the clock and audio systems
will be cancelled. So before starting work, make a record of the contents memorized by each me\
mory system.
Then when work is finished, reset the clock and audio system as before.
When the vehicle has tilt and telescopic steering, power seat, outside r\
ear 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 operation is finished, it will be necessary to explain this\
fact to the customer, and
request 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.

When removing the steering wheel pad or handling a new steering wheel pad, keep the pad upper surfa\
ce
facing upward. Also, lock the lock lever of the twin lock type connector\
at the rear of the pad and take care
not to damage the connector.
(Storing the pad with its metallic surface up may lead to a serious accident if \
the airbag inflates for some
reason).

Store the steering wheel pad where the ambient temperature remains below\
93 °C (200 °F), without high
humidity and away from electrical noise.

Never use airbag parts from another vehicle. When replacing airbag parts\
, replace them with new parts.

Never disassemble or repair the steering wheel pad, center airbag sensor asse\
mbly or front airbag sensors.

Before repairing the body, remove the airbag sensors if during repair shocks are likely to be app\
lied to the
sensors due to vibration of the body or direct tapping with tools or oth\
er parts.

Do not reuse a steering wheel pad or front airbag sensors.
After evaluating whether the center airbag sensor assembly is damaged or not, decide whether or not to reuse
it. (See the Repair Manual for the method for evaluating the center airbag\
sensor assembly.)

When troubleshooting the airbag system, use a high±impedance (Min. 1\
0k W/V) tester.

The vehicle wiring harness exclusively for the airbag system is distinguish\
ed by corrugated yellow tubing, as
are the connectors.

Do not measure the resistance of the airbag squib.
(It is possible this will deploy the airbag and is very dangerous.)

If the wire harness used in the airbag system is damaged, replace the wh\
ole wire harness assembly.
When the connector to the airbag front sensors can be repaired alone (when \
there is no damage to the wire
harness), use the repair wire specially designed for the purpose.
(Refer to the Repair Manual for the applicable Model year for details o\
f the replacement method.)

INFORMATION LABELS (NOTICES) are attached to the periphery of the airbag componen\
ts. Follow the
instructions on the notices.
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