1991 LEXUS SC300 cruise control

No.Part NameRelated Systems or Parts
22MAIN
Upstream of ALT±S and EFI Fuse
23AM2
Charging System
Engine23AM2
AIR±BAG System
24ABS NO. 2
ABS and TRAC
25INJ
Charging System
Engine25INJ
AIR±BAG System
26DEF
Defogger System

Power Seat System
Sliding Roof System

A/C System
Liquid Crystal Inner Mirror System
27DOME
Combination Meter System
Interior Light System27DOME
ABS and TRAC
Wireless Door Lock Control System

Cruise Control System
Auto±Tilt away Steering

Theft Deterrent System
28EFI
Engine
29HAZ HORN
Turn Signal and Hazard Warning Light System29HAZ±HORN
Horn System
30RADIO NO. 1
Audio System
31TEL
TEL System
32ALT±S
Charging System
33TRAC
ABS and TRAC
34HEAD (RH±LWR)
Headlight System
35HEAD (LH±LWR)
Headlight System
36HEAD (RH±UPR)
Headlight System
37HEAD (LH±UPR)
Headlight System
38HTR
Blow Motor
±
BODY ELECTRICAL SYSTEM Power SourceBE±19
WhereEverybodyKnowsYourName

Shift Lock ECU
Tilt and Power
Telescopic ECU
Airbag ECU
Cruise Control ECU Engine ECUABS and Traction ECU
(w/ Traction System) or
ABS ECU
(w/o Traction System)
Theft Deterrent and
Door Lock ECU
(w/ Traction System)
Traction ECU
Remote Control Mirror ECU A/C Control Amplifier
PPS ECU
Engine Cooling Fan ECU
Component to be aligned
Section of repair manual
for relevant model year
Front Wheels Suspension and Axle (SA) section
Rear Wheels Suspension and Axle (SA) section
Propeller Shaft Propeller Shaft (PR) section
2. BRAKE SYSTEM
The brake system is one of the most important safety components. Always \
follow the directions and
notes given in section BR of the repair manual for the relevant model ye\
ar when handling brake sys-
tem parts.
NOTICE: When repairing the brake master cylinder or TRAC system, bleed t\
he air out of the TRAC
system.
3. DRIVE TRAIN AND CHASSIS
The drive train and chassis are components that can have great effects on the running performance
and vibration resistance of the vehicle. After installing components in \
the sections listed in the table
below, perform alignments to ensure correct mounting angles and dimensions. P\
articularly accurate
repair of the body must also be done to ensure correct alignment.
HINT: Correct procedures and special tools are required for alignment. Alway\
s follow the directionsgiven in the repair manual for the relevant model year during alignment \
and section DI of this manual.
4. ECU (ELECTRONIC CONTROL UNIT)
Locations of ECUs
INTRODUCTIONIN-8
WhereEverybodyKnowsYourName

EG21S±02
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
HINT: Inspect and adjust the valve clearance when the en-
gine is cold.
1. DISCONNECT NEGATIVE TERMINAL CABLE FROM BATTERY
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.
2. DRAIN ENGINE COOLANT
3. REMOVE THROTTLE BODY COVER
(a) Disconnect the EVAP hose from the hose clamp.
(b) Remove the cap nut.
(c) Loosen the 2 bolts, and remove the hose clamp and throttle
body cover.
4. DISCONNECT CONTROL CABLES TO THROTTLE BODY Disconnect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
5. REMOVE INTAKE AIR CONNECTOR
(a) Disconnect the following hoses: (1) Air hose from IAC valve
(2) Air hose (from air control valve on PS pump) from intake
air connector
EG±14
±
1UZ±FE ENGINE ENGINE MECHANICAL
WhereEverybodyKnowsYourName

(b) Push the front side of the upper high±tension cord cover, andfit the front side claw groove of the upper high±tension cord
cover to the claw of the lower high ±tension cord cover.
(c) Install the upper high±tension cord cover with the 2 bolts.
37. REINSTALL INTAKE AIR CONNECTOR
(a) Connect the end portions of the intake air connector to the throttle body and air cleaner hose.
(b) Tighten the 2 hose clamps
(c) Install the bolt holding the intake air connector to the cylinder head cover.
(d) Connect the following hoses: (1) Air hose to IAC valve
(2) Air hose (from air control valve on PS pump) to intake air
connector
38. RECONNECT CONTROL CABLES TO THROTTLE BODY Connect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
39. REINSTALL THROTTLE BODY COVER
(a) Install the thro ttle body cover and hose clamp with the cap nut
and 2 bolts.
(b) Install the EVAP hose to the hose clamp.
±
1UZ±FE ENGINE ENGINE MECHANICALEG±31
WhereEverybodyKnowsYourName

(b) Remove the nut and 3 bolts, and disconnect the PS pumpfrom the engine.
5. REMOVE TWC (FRONT)
(a) Remove the 4 bolts holding the pipe support bracket to the transmission.
(b) Remove the 4 bolts and nuts holding the front exhaust pipe to the TWC, and remove the pipe support bracket.
(c) Disconnect the front exhaust pipe from the TWC, and remove
the 2 gaskets.
(d) Using a 14 mm deep socket wrench, remove the 3 nuts, TWC
and gasket. Remove the 2 TWC.
6. REMOVE THROTTLE BODY COVER
(a) Disconnect the EVAP hose from the hose clamp.
(b) Remove the cap nut.
(c) Loosen the 2 bolts, and remove the hose clamp and throttle body cover.
7. DISCONNECT CONTROL CABLES FROM THROTTLE BODY
Disconnect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
8. REMOVE RH IGNITION COIL
(a) Disconnect the ignition coil connector.
(b) Remove the 2 bolts and ignition coil.
EG±76
±
1UZ±FE ENGINE ENGINE MECHANICAL
WhereEverybodyKnowsYourName

(g) Connect the water bypass hose to the IAC valve.
38. INSTALL RH IGNITION COIL
(a) Install the ignition coil with the 2 bolts.
(b) Connect the ignition coil connector.
39. CONNECT CONTROL CABLES TO THROTTLE BODYConnect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
40. INSTALL THROTTLE BODY COVER
(a) Install the thro ttle body cover and hose clamp with the cap nut
and 2 bolts.
(b) Install the EVAP hose to the hose clamp.
41. INSTALL POWER STEERING (PS) PUMP
(a) Install the PS pump with the nut and 3 bolts. Alternately tighten the bolts and nut.
Torque:
39 NVm (400 kgf Vcm, 29 ft Vlbf) for bolt
43 N Vm (440 kgf Vcm, 32 ft Vlbf) for nut
EG±134±
1UZ±FE ENGINE ENGINE MECHANICAL
WhereEverybodyKnowsYourName

7. REMOVE THROTTLE BODY COVER
(a) Disconnect the EVAP hose from the hose clamp.
(b) Remove the cap nut.
(c) Loosen the 2 bolts, and remove the hose clamp and throttlebody cover.
8. DISCONNECT CONTROL CABLES TO THROTTLE BODY Disconnect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
9. REMOVE AIR CLEANER
(a) Disconnect the VAF meter connector.
(b) Remove the hose clamp bolt holding the air cleaner hose to the intake air connector.
(c) Remove the 4 bolts.
(d) Disconnect the air cleaner hose from the intake air connector.
(e) Disconnect the air duct from the air cleaner case, and remove
the air cleaner.
10. D I S C O N N E C T VA CUUM HOSE (A) (FROM PS AIR
CONTROL VALVE) FROM AIR INTAKE CHAMBER
11. REMOVE INTAKE AIR CONNECTOR
(a) Disconnect the following hoses from the intake air connector:
(1) Air hose (from IAC valve)
(2) Air hose (from air control valve on PS pump)
(b) Remove the hose clamp bolt holding the intake air connector to the throttle body.
(c) Remove the bolt and intake air connector.
EG±140
±
1UZ±FE ENGINE ENGINE MECHANICAL
WhereEverybodyKnowsYourName

29. INSTALL AIR CLEANER
(a) Connect the air cleaner case to the air duct.
(b) Connect the air cleaner hose to the intake air connector.
(c) Install the air cleaner with the 3 bolts.
(d) Tighten the hose clamp bolt holding the air cleaner hose tothe intake air connector.
(e) Connect the VAF meter connector.
30. CONNECT CONTROL CABLES TO THROTTLE BODY
Connect the following cables:
(1) Accelerator cable
(2) Transmission throttle control cable
(3) Cruise control actuator cable
31. INSTALL THROTTLE BODY COVER
(a) Install the thro ttle body cover and hose clamp with the cap nut
and 2 bolts.
(b) Install the EVAP hose to the hose clamp.
32. INSTALL DRIVE BELT Install the drive belt by turning the drive belt tensioner coun-
terclockwise.
HINT: The pulley bolt for the dive belt tensioner has a left±
hand thread.
33. INSTALL BATTERY
EG±202
±
1UZ±FE ENGINE ENGINE MECHANICAL
WhereEverybodyKnowsYourName