1991 LEXUS SC300 service

SERVICE SPECIFICATIONS
SERVICE DATA
TerminalFront airbag sensor resistance

S ±
A755±885

S
A

S ± S
755 885



S ± ALess than 1

TORQUE SPECIFICATIONS
Part tightenedNVmkgf Vcmft Vlbf
Steering wheel3536026Steering wheel
Steering wheel pad
35
7.4
360
75
26
65 in. Vlbfg
Front airbag sensor25260 19g
Center airbag sensor assembly131309
AB±98±
SRS AIRBAG Disposal of Steering Wheel Pad (with Airbag)
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GENERAL DESCRIPTION
The LEXUS SC400 is equipped with an SRS (Supplemental Restraint System) a\
irbag.
Failure to carry out service operations in the correct sequence could cause the\
airbag system to unex-
pectedly deploy during servicing, possibly leading to a serious accident.
Further, if a mistake is made in servicing the airbag system, it is possible the\
airbag may fail to operate
when required.
Before performing servicing (including removal or installation of parts, insp\
ection or replacement), be
sure to read the following items carefully, then follow the correct procedure described in the repair
manual.
1. Malfunction symptoms of the airbag system are difficult to confirm, so the diagnostic codes become themost important source of information when troubleshooting.
When troubleshooting the airbag system, always inspect the diagnostic co\
des before disconnecting the
battery (See page AB±25).
2. Work must be started after approx. 20 seconds or longer from the time the ig\
nition switch is turned to the LOCK position and the negative (±) terminal cable is disconnec\
ted from the battery. (The
airbag system is equipped with a back±up power source so that if work is sta\
rted within 20 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 sys-
tems will be cancelled. So before starting work, make a record of the conten\
ts memorized by the audio
memory system. Then when work is finished, reset the audio systems as before a\
nd adjust 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 customer, 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 airbag does not deploy, the front airbag sensors and
the steering wheel pad should be inspected (See page AB±9).
4. Never use airbag parts from another vehicle. When replacing parts, replace them with new parts.
5. Before repairs, remove the airbag sensors if shocks are likely to be applied to the sensors during repairs.
6. Never disassemble and repair the front airbag sensors, center airbag sensor a\
ssembly or steering
wheel pad in order to reuse it.
7. If the front airbag sensors, center airbag assembly or steering wheel pa\
d have been dropped, or if there are cracks, dents or other defects in the case, bracket or conn\
ector, replace them with new
ones.
8. Do not expose the front airbag sensors, center airbag sensor assembly or\
steering wheel pad directly to hot air or flames.
9. Use a volt/ohmmeter with high impedance (10 kW/V minimum) for troubleshoo\
ting of the electrical circuit.
10. Information labels are attached to the periphery of the airbag components. Follow t\
he instructions
on the notices.
11. After work on the airbag system is completed, perform the airbag warning\
light check (See page AB±30 ).
AB±2
SRS AIRBAG
± General Description
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PREPARATION
SST (SPECIAL SERVICE TOOLS)
09082±00700SRS Airbag
Deployment Tool
09213±31021Crankshaft Pulley
Puller
09843±18020Diagnosis Check
Wiring
Steering wheel
RECOMMENDED TOOLS
09042±00010Torx Socket
T30
09042±00020Torx Socket
T30
09082±00015TOYOTA
Electrical Tester
Center airbag sensor assembly
Steering wheel pad
EQUIPMENT
Part NameNote
Torque wrench
AB±13SRS AIRBAG ± Preparation
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CLEARING OF DIAGNOSTIC CODE
1. CLEARING OF MALFUNCTION CODE(EXCEPT CODE 41)
Remove the battery negative (±) terminal or ECU±B fuse for
10 seconds or more with the ignition switch OFF.
NOTICE: When connecting the battery after cancelling
the malfunction code, always do it with the ignition
switch in LOCK position. If the battery is connected with
the ignition switch in ACC or ON position, there are cases
when the diagnosis system does not operate normally.
HINT:
wCode 41 cannot be cleared by this method.
wThe lower the temperature, the longer the battery
negative (±) terminal must be left off.
wOther memory systems (clock, audio system) will also
be cancelled out (See page AB±2).
2. CLEARING OF MALFUNCTION CODE 41 STORED IN MEMORY
(a) Connect service wires to terminals Tc and AB of theTDCL.
(b) Turn the ignition switch ACC or ON and wait approx. 6 seconds.
(c) S ta rtin g with th e Tc te rmin a l, ap p ly bo d y gr ound
alternately to terminal Tc and terminal AB twice each in
cycles of 1.0 ± 0.5 seconds. Finally, keep applying body
ground to terminal Tc.
HINT: When alternating between body ground of terminals Tc
and AB release one from body ground while applying it to the
other terminal. The time interval in between must be within
the following conditions. If it is out of the conditions, code 41
will not be cleared.
(d) After several seconds, when the airbag warning light
starts to blink in a 64 msec. cycle, cancellation is
completed.
HINT: This method clears not only code No. 41, but also other
malfunction codes all at once.
Except when instructed by the troubleshooting procedure,
use this method only when the repair procedure is completed
(See page AB±25).
AB±32
SRS AIRBAG
± Troubleshooting
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(1) Connect connector to center airbag sensorassembly.
(2) Using a service wire, connect D
+, D± on spiral
cable side of connector between spiral cable
and steering wheel pad.
(3) Connect negative (±) terminal cable to battery, and wait at least 2 seconds.
Check squib circuit.
Codes other than code 11 may be output at this
time, but this is not relevant.
Measure resistance between D+, D± on spiral cable
side of connector between spiral cable and steer-
ing wheel pad and body ground.
Go to step [ 8 ].
Diagnostic code 11 is not output.
Resistance: 1 M
or higher
Replace center airbag sensor assembly.
Check center airbag sensor assembly.
(1) Turn ignition switch ACC or ON and wait at
least 20 seconds.
(2) Using SST, connect terminals Tc and E
1 of
TDCL.
SST 09843±18020
(3) Check diagnostic code. AB±45
SRS AIRBAG
± Troubleshooting
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(1) Turn ignition switch LOCK.
(2) Disconnect negative (±) terminal cable frombattery.
(3) Connect connector to center airbag sensor assembly.
(4) Using a service wire, Connect D
+ and D± on
spiral cable side of connector between spiral
cable and steering wheel pad.
(5) Connect negative (±) terminal cable to battery, and wait at least 2 seconds.
Check squib circuit.
Codes other than code 12 may be output at this
time, but this is not relevant.
Measure voltage at D+ on spiral cable side of con-
nector between spiral cable and steering wheel
pad.
Go to step [ 7 ].
Resistance: 1 V
Replace center airbag sensor assembly.
Check center airbag sensor assembly.
(1) Turn ignition switch ACC or ON and wait at least 20 seconds.
(2) Using SST, connect terminals Tc and E
1 of
TDCL.
SST 09843±18020
(3) Check diagnostic code.
Diagnostic code 12 is not output. AB±51
SRS AIRBAG
± Troubleshooting
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SERVICE SPECIFICATIONS
SERVICE DATA
AT0GH±02 Line pressure (wheel locked)\
 \

 \
 \
382±441 kPa 3.9±4.5 kgf/cm255±64 psi
 Engine idling D position\
 \

 \
 \
637±716 kPa 6.5±7.3 kgf/cm292±104 psi
 R position\
 \

\
1,265±1,402 kPa 12.9±14.3 kgf/cm2183±203 psi AT stall (Throttle valve opened) D position\
 \

 \
 \
1,726±2,060 kPa 17.6±21.0 kgf/cm2250±298 psi R position\
 \

 ECM SLN termina lNot ground\
 \
177±255 kpa 1.8±2.6 kgf/cm226±37 psi
 Ground\
 \
0
 Engine stall revolution\
 \
2,200+150 RPM
 Time lag N position " D position\
 \
Less than 1.2 seconds
 N position " R position\
 \
Less than 1.5 seconds
 Engine idle speed (Cooling fan and A/C OFF
)N position\
 \
650 RPM
 \
 \
Boot end face and inner cable stopper Throttle cable adjustment (Throttle valve fully closed)\
 \

 \
 \
0±1 mm 0±0.04 in.
 Torque converter clutch installing (Correct distance)\
 \
17.1mm 0.673 in.
 Drive plate runout Limit\
 \
0.20 mm 0.0079 in.
SHIFT POINT (Kick±down foot switch activated)
 Shift position Shifting point Vehicle speed km/h (mph)2
  Throttle valve fully opened 1"2 67±71 (42±44)
  2" 3 118±124 (73±77)
  3" O/D (NORM) 170±177 (106±110)
  3" O/D (PWR) 179±186 (111±116)
 D position (NORM or PWR) O/D "3 164±170 (102±106)
  3" 2 105±111 (65±69)  2" 1 53±57 (33±35) 

2 iti
 

Throttle valve fully opened 1
"2
 

67±71 (42±44)
 2 position
(NORM or PWR) 3
" 2 106±112 (66±70)
 
(NORM or PWR)
 2" 1 53±57 (33±35)
 L position Throttle valve fully opened 3 "2 104±109 (65±68)
 
L osition
(NORM or PWR) 2" 1 57±63 (35±39)
±
A340E (1UZ±FE) AUTOMATIC TRANSMISSION SERVICE SPECIFICATIONSAT±121
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SHIFT POINT (Kick±down foot switch deactivated)
 Shift position Shifting point Vehicle speed km/h (mph) 


 

Throttle valve fully opened 1
"2
 

67±71 (42±44)
  2
" 3 118±124 (73±77)
  3" O/D 155±161 (96±100)
 D position O/D "3 128±134 (79±83)
 
D osition
(NORM) 3" 2 71±75 (44±47)
  2" 1 10±13 (6±8)
  Throttle valve fully closed 3 "O/D 32±35 (20±22)  O/D "3 23±26 (14±16) 


 

Throttle valve fully opened 1
"2
 

67±71 (42±44)
  2
" 3 118±124 (73±77)
  3" O/D 179±186 (111±116)
 D position O/D "3 149±155 (93±96)
 
D osition
(PWR) 3" 2 95±100 (59±62)
  2" 1 22±26 (14±16)
  Throttle valve fully closed 3 "O/D 32±35 (20±22)  O/D "3 23±26 (14±16) 

2 iti
 

Throttle valve fully opened 1
"2
 

67±71 (42±44)
 2 position
(NORM or PWR) 3
" 2 106±112 (66±70)
 
(NORM or PWR)
 2" 1 10±13 (6±8)
 L position Throttle valve fully opened 3 "2 104±109 (65±68)
 
L osition
(NORM or PWR) 2" 1 57±63 (35±39)
LOCK±UP POINT
 


D position km/h (mph)
Throttle valve opening 5% 

Lock±up ON
 

Lock±up OFF
 3rd Gear (O/D switch OFF) 83±88 (52±55) 77±82 (48±51)
 O/D Gear 56±60 (35±37)1 53±57 (33±35)
AT±122±
A340E (1UZ±FE) AUTOMATIC TRANSMISSION SERVICE SPECIFICATIONS
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