1991 LEXUS SC300 shock

31. INSTALL THROTTLE BODY COVERInstall the throttle body cover and hose clamp with the two
bolts and cap nut.
32. INSTALL DRIVE BELT Install the drive belt by turning the drive belt tensioner coun-
terclockwise.
HINT: The pulley bolt for the belt tensioner has a left±hand
thread.
33. INSTALL BATTERY
34. FILL WITH ENGINE COOLANT (See page CO±7)
35. FILL COOLING FAN RESERVOIR TANK WITH FLUID (See page CO±23)
36. FILL WITH ENGINE OIL (See page LU±7)
Capacity:
Drain and refill
w/Oil filter change4.8 liters (5.1 US qts, 4.2 lmp. qts)
w/o Oil filter change 4.5 liters (4.8 US qts, 4.0 lmp. qts)
Dry fill 6.0 liters (6.3 US qts, 5.3 lmp. qts)
37. START ENGINE AND CHECK FOR LEAKS
38. CHECK AUTOMATIC TRANSMISSION FLUID LEVEL
39. CHECK IGNITION TIMING (See page IG±28)
Ignition timing:
8±125 BTDC @ idle
(w/ Terminals TE1 and E1 connected)
40. INSTALL ENGINE UNDER COVER
41. INSTALL HOOD
42. PERFORM ROAD TEST Check for abnormal noise, shock, slippage, correct shift
points and smooth operation.
32. RECHECK ENGINE COOLANT AND ENGINE OIL LEVELS
±
ENGINE MECHANICAL Cylinder BlockEM±177
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Diag. Code 16ECT Control Signal Malfunction
CIRCUIT DESCRIPTION
The signal from the ECT CPU retards the ignition timeing of the engine duri\
ng ECT gear shifting, thus mo-
mentarily reducing torque output of the engine for smooth clutch operati\
on inside the transmission and re-
duced shift shock.
Code No.Diagnostic Code Detecting ConditionTrouble Area
16Fault in communications between the engine
CPU and ECT CPU in the ECU.
ECU
If the ECU records the diagnostic code ª16º in memory, it prohibits the torque control of the ECT which per-
forms smooth gear shifting.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
Are there any other codes (besides Code 16)
being output?
Replace engine & ECT ECU. Go to relevant diag. code chart.
±
ENGINE TROUBLESHOOTING Circuit InspectionTR±61
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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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DESCRIPTION
RS00S±02
The SRS (Supplemental Restraint System), together with the seat belt, is designed to help protect the driv-
er. Frontal inspect, the airbag sensor detect the shock, and if the front±\
to±rear shock is greater than a spe-
cified value, an airbag stored in the steering wheel pad is inflated ins\
tantaneously to help reduce the shock
to the driver.
LOCATION OF COMPONENTS
RS00T±02
RS±6±
SUPPLEMENTAL RESTRAINT SYSTEM DESCRIPTION
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When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than a predeter-
mined level, the SRS is activated automatically. A safing sen-
sor is designed to go on at a smaller deceleration rate than
the front and center airbag sensors. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which hap-
pens when a safing sensor and a front airbag sensor and/or
the center airbag sensor go on simultaneously. When a de-
celeration force acts on the sensors, two squibs in the driver
airbag and front passenger airbag ignite and generate gas.
The gas discharging into the driver and front passenger air-
bags rapidly increases the pressure inside the bags breaking
open the steering wheel pad and instrument panel door.
Bag inflation then ends, and the bags deflate as the gas is
discharged through discharge holes at the bag's rear or side.
RS±14±
SUPPLEMENTAL RESTRAINT SYSTEM OPERATION
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2. REMOVE STEERING WHEEL PAD CONNECTORRemove the connector on the steering wheel pad rear sur-
face from the inflater cover.
3. FIX STEERING WHEEL PAD TO DISC WHEEL WITH TIRE
(a) Install the 4 bolts with washer in the 4 bolt holes in the steering wheel pad.
Bolt:
L 35.0 mm (1.398 in.) M 6.0 mm (0.236 in.) Pitch 1.0 mm
(0.039 in.)
NOTICE:
wTighten the bolts by hand until the bolts become difficult
to turn.
w Do not tighten the bolts too much.
(b) Using a service±purpose wire harness for vehicle tie down
the steering wheel pad to the disc wheel.
Wire harness: Stripped wire harness section
1.25 mm
2 or more (0.0019 in2 or more)
HINT: To calculate the square of the stripped wire harness
section ±±
Square = 3.14 x (Diameter)2 divided by 4
CAUTION: If a wire harness which is too thin or some oth-
er thing is used to tie down the steering wheel pad it may
be snapped by the chock when the airbag is deployed,
this is highly dangerous. Always use a wire harness for
vehicle use which is at least 1.25 mm
2 (0.0019 in2.).
(1) Using 3 wire harnesses, wrap the wire harnesses at least 2 times each around the bolts installed on the left and
right sides of the steering wheel pad.
CAUTION:
w Tightly wind the wire harness around the bolts so that
there is no slack.
w If there is slackness in the wire harness, the steering
wheel pad may come loose due to the shock when the
airbag is deployed, this is highly dangerous.
RS±24±
SUPPLEMENTAL RESTRAINT SYSTEM STEERING WHEEL PAD AND SPIRAL CABLE
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(2) Face the upper surface of the steering wheel pad upward.
(3) Separately tie the left and right sides of the steering wheelpad to the disc wheel through the hub nut holes.
(c) Position the steering wheel pad connector so that it hangs downward through a hub hole in the disc wheel.
CAUTION:
w Make sure that the wire harness is tight. It is very
dangerous if looseness in the wire harness results in the
steering wheel pad coming free through the shock of the
airbag deploying.
w Always tie down the steering wheel pad with the pad side
facing upward. It is very dangerous if the steering wheel
pad is tied down with the metal surface facing upward as
the wire harness will be cut by the shock of the airbag
deploying and the steering wheel pad will be thrown into
the air.
HINT: The disc wheel will be marked by airbag deployment,
so use a redundant disc wheel.
4. CONFIRM FUNCTIONING OF SST (See page RS±27)
SST 09082±00070
5. INSTALL SST CAUTION: Place the disc wheel on level ground.
(a) C onnect the SST connector to the steering wheel pad
connector.
SST 09082±00700
NOTICE: To avoid damaging the SST connector and wire
harness, do not lock the secondary lock of the twin lock.
Also provide some slack for the SST wire harness inside
the disc wheel.
(b) Move the SST to at least 10 m (33 ft) away from the steering wheel pad tied down on the disc wheel.
±
SUPPLEMENTAL RESTRAINT SYSTEM STEERING WHEEL PAD AND SPIRAL CABLERS±25
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6. COVER STEERING WHEEL PAD WITH CARDBOARDBOX OR TIRES
Covering Method Using Cardboard Box:
Cover the steering wheel pad with the cardboard box and
weigh the cardboard box down in four places with a at least
196 N (20 kgf, 44 lbf).
Size of cardboard box:
Must exceed the following dimensions±
x = 460 mm (18.11 in.) When dimension y of the cardboard box exceeds the
diameter of the disc wheel with tire the steering wheel
pad is tied to±
x = 460 mm (18.11 in.) + width of tire
y = 650 mm (25.59 in.)
NOTICE: If a cardboard box smaller than the size speci-
fied is used, the cardboard box will be broken by the
shock of the airbag deployment.
Covering Method Using Tires:
Place at least 3 tires without disc wheel on top of the disc
wheel with tire to which the steering wheel pad is tied.
Tire size: Must exceed the following dimensions± Width 185 mm (7.28 in.)
Inner diam 360 mm (14.17 in.)
CAUTION: Do not use tires with disc wheels.
NOTICE: The tires by marked by the airbag deployment,
so use redundant tires.
7. AIRBAG DEPLOYMENT
(a) Connect the SST red clip to the battery positive (+) terminal and the black clip to the battery negative (±) terminal.
(b) Confirm that no±one is within 10 m (33 ft) of the disc wheel the steering wheel pad is tied to.
(c) Press the SST activation switch and deploy the airbag. HINT: The airbag deploys simultaneously as the LED of the
SST activation switch lights up.
RS±26±
SUPPLEMENTAL RESTRAINT SYSTEM STEERING WHEEL PAD AND SPIRAL CABLE
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