engine LEXUS SC400 1991 Service Repair Manual

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ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
A 1 A/C Ambient Temp. Sensor E 1 ECT Solenoid
A 2 A/C Lock Sensor and A/C Magnetic Clutch E 2 EFI Water Temp. Sensor
A 3 A/C High Pressure SW E 3 EGR Gas Temp. Sensor (for USA Spec.)
A 4 ABS Actuator E 5 Engine Hood Courtesy SW
A 5 ABS Actuator (w/ Traction Control) E 6 Engine Oil Level Warning SW
A 6 ABS Actuator (w/ Traction Control)
A 7 ABS Speed Sensor Front LH F 1 Front Airbag Sensor LH
A 8 ABS Speed Sensor Front RH F 2 Front Airbag Sensor RH
A 9 Air Flow Meter F 3 Front Clearance Light LH
A 10 Alternator F 4 Front Clearance Light RH
A 11 Alternator F 5Front Side Marker Light LH
A 33 ABS Actuator (w/o Traction Control) F 6 Front Side Marker Light RH F 7 Front Turn Signal Light LH
B 1 Brake Fluid Level SW F 8 Front Turn Signal Light RH
B 6 Back±Up Light SW (for M/T) F 9 Fuse Block
C 3 Check Connector H 1 Headlight Hi LH
C 6 Cornering Light LH H 2 Headlight Hi RH
C 7 Cornering Light RH H 3 Headlight Lo LH
C 8 Cruise Control Actuator H 4 Headlight Lo RH H 5 Horn LH
D 13 Distributor H 6 Horn RH
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Position of Parts in Engine Compartment
I 1 ISC Valve S 3Speed Sensor No. 1
I 2 Igniter S 4 Speed Sensor No. 2 (for ECT)
I 4 Ignition Coil S 6 Starter
I 6 Injector No. 1 S 7 Starter
I 7 Injector No. 2 S 8 Sub Throttle Actuator
I 8 Injector No. 3 S 9 Sub Throttle Position Sensor
I 9 Injector No. 4
I 10 Injector No. 5 T 1 Theft Deterrent Horn
I 11 Injector No. 6 T 2 Throttle Position Sensor T 3 Traction Brake Actuator
K 1 Knock Sensor No. 1 (on Front Side) T 4 Traction Brake Actuator
K 2 Knock Sensor No. 2 (on Rear Side) T 5 Traction pump and Motor
N 1 Neutral Start SW, Back±Up Light SW and A/T Indicator SW V 1 VSV (for EGR) (Exc. USA Spec) (for A/T) V 2 VSV (for EVAP)
N 2 Noise Filter (for Defogger System) V 4 VSV (for Water Valve)
N 3 Noise Filter (for Ignition System) V 7 VSV (for Intake Control Valve)
O 2 Oil Pressure SW W 1 Washer Level SW
O 3 Oxygen Sensor Main No. 1 (on Front Side) W 2 Washer Motor
O 4 Oxygen Sensor Main No. 2 (on Rear Side) W 3 Water Temp. Sender W 5 Wiper Motor
P 1 PPS Solenoid
P 20 Power Steering Pressure SW
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ELECTRICAL WIRING ROUTING
Position of Parts in Instrument Panel
A 12 A/C Control Assembly C 9 CD Player
A 13 A/C Control Assembly C 10 Center Airbag Sensor Assembly
A 14 A/C Control Assembly C 11 Cigarette Lighter
A 15 A/C Control SW and Radio SW C 12 Combination Meter
A 16 A/C Evaporator Temp. Sensor C 13 Combination Meter
A 17 A/C Power Transistor C 14Combination Meter
A 18 A/C Power Transistor C 15 Combination SW
A 19 A/C Room Temp. Sensor C 16 Combination SW
A 20 A/C Solar Sensor C 17 Combination SW
A 21 A/T Indicator Light (for Shift Lever) C 19 Cruise Control ECU
A 22 ABS ECU (for M/T, w/o Traction Control) C 23 Clutch Start SW
A 23 ABS ECU (for M/T, w/o Traction Control) C 24 Cruise Control Clutch SW
A 24 ABS and Traction ECU
A 25 ABS and Traction ECU D 1 Diode (for Brake Fluid Level)
A 26 ABS and Traction ECU D 2 Diode (for Parking Brake)
A 27 Air Mix Control Servo Motor D 3 Diode (for Tension Reduser)
A 28 Air Vent Mode Control Servo Motor
A 29 Airbag Squib E 8 ECT Pattern Select SW
A 33 Air Inlet Control Servo Motor E 9 Engine and ECT ECU (for A/T) E 10 Engine and ECT ECU (for A/T)
B 2 Blower Motor E 11 Engine ECU (for M/T)
B 3 Blower Resistor (for Low Speed) E 12 Engine ECU (for M/T)
F 10 Fuel Lid Opener SW
G 1 Glove Box Light
G 2 Glove Box Light SW
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CODEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
EB1ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO 2)EB2ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO. 2)
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CODEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IE1ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
IE2ENGINE ROOM MAIN WIRE AND COWL WIRE (BEHIND GLOVE BOX)
IF1FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)IF2FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)
IG1INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO 5)IG2INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IG3INSTRUMENT PANEL WIRE AND COWL WIRE (RIGHT KICK PANEL)
IH1COWL NO. 2 WIRE AND COWL WIRE (BEHIND COMBINATION METER)
II1ENGINE WIRE AND A/C WIRE (BEHIND GLOVE BOX)
IJ1ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ2ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IK1ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)IK2ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
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CODEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IN1ENGINE ROOM MAIN WIRE AND A/C WIRE (BEHIND GLOVE BOX)
IO1ENGINE ROOM MAIN WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
IP1FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)IP2FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)
IQ1INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)IQ2INSTRUMENT PANEL WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)
IR1CONSOLE BOX WIRE AND A/C WIRE (BEHIND GLOVE BOX)IR2CONSOLE BOX WIRE AND A/C WIRE (BEHIND GLOVE BOX)
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CODEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
BS1ENGINE ROOM MAIN WIRE AND FLOOR WIRE (LEFT KICK PANEL)
BT1FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)
BU1INSTRUMENT PANEL WIRE AND FLOOR WIRE (LEFT KICK PANEL)
BV1
BV2FLOOR NO. 3 WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)
BV3
FLOOR NO. 3 WIRE AND CONSOLE BOX WIRE (UNDER THE INSTRUMENT PANEL CENTER)
BW1ENGINE ROOM MAIN WIRE AND FLOOR NO. 3 WIRE (RIGHT KICK PANEL)
BX1FLOOR NO. 3 WIRE AND COWL WIRE (RIGHT KICK PANEL)
BY1INSTRUMENT PANEL WIRE AND FLOOR NO. 3 WIRE (RIGHT KICK PANEL)
BZ1ROOF WIRE AND MOON ROOF WIRE (FRONT SIDE OF ROOF LEFT)
Bc1FLOOR NO 3 WIRE AND FLOOR WIRE (UNDER THE LEFT SIDE OF REAR SEAT CUSHION)Bc2FLOOR NO. 3 WIRE AND FLOOR WIRE (UNDER THE LEFT SIDE OF REAR SEAT CUSHION)
Bd1FLOOR NO. 3 WIRE AND LUGGAGE NO. 2 WIRE (RIGHT SIDE OF LUGGAGE COMPARTMENT)
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CORNERING LIGHT RELAY 3±5 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION
C15 LIGHT CONTROL SW [COMB. SW]
13±4 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION
C16 CORNERING LIGHT SW [COMB. SW]
8±11 : CLOSED WITH TURN SIGNAL LEVER AT LEFT POSITION
8±10 : CLOSED WITH TURN SIGNAL LEVER AT RIGHT POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C 626C1528I16A29 (USA)
C 726C1628I16B29 (CANADA)
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
423LEFT KICK PANEL (J/B NO.1 LEFT)
523LEFT KICK PANEL (J/B NO.1 RIGHT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1I
1J20COWL WIRE
1K
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IE136ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
EA34FRONT SIDE OF RIGHT FENDER
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
E 434ENGINE ROOM MAIN WIRE
12 56
X1213 A
B
C 6, C 7 C15 C16 I16
I1 6
(
CA NA DA ) (
US A )
BLACK
GRAY
X
XXX13 4
X
X X
8X 10 11
SERVICE HINTS
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1K
4 1I
10
B
9B 64 A 12
1
IJ2
2IJ2 1IJ1
6
PARKING
BRAKE SWM42
4 31
5
7
6
23
1 25A
STOP
7. 5A
ST
POTENTIO METER
CRUIS E CONTROL ACTUATOR GN DL
MC
MO
VR3
VR2
VR1
MAGNETIC
CLUTCH
S2 IDL1 OD1
ECT IDL OD VR1 VR2 VR3 MC MO L STP±
N& C STP+
CRUISE CONTROL ECU
STOP
LIGHT
SW
B±W B±W
W
B±W
W
W
G±W BR±Y
R
W±R
W±R
R
BR±Y
R±B
LG±R P
LG
G±R
W
R±L R±B
LG±R P
LG
G±R B±W
W±B
I9
S12
C19
P3C8
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
R±W
B
PKB
ENGINE AND ECT ECU E9 ,E10
I7
EA
IE 2
10
IE2
11
IE2
5
IE2
1
IE2
6
IE2
2
IG1
19
IJ2
9
B (
CANA DA )
(
USA )
R±L
22 23 9 3 24 25 26 12 11 10 16 1
A B IJ2
10
I9
C24 C23
CLUTCH
START SW CRUISE
CONTROL
CLUTCH SW(
A/T )
B±W
BB±W
B±W
B±W
(
A/T )
(
A/T )
1
2
2
21
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7. AUTO CANCEL FUNCTION
A) IF ANY OF THE FOLLOWING OPERATING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE SET SPEED IS
ERASED, CURRENT FLOW TO MAGNETIC CLUTCH IS STOPPED AND THE CRUISE CONTROL IS RELEASED. (MAIN SWITCH TURNS
OFF).
WHEN THIS OCCURS, THE IGNITION SWITCH MUST BE TURNED OFF ONCE BEFORE THE MAI\
N SWITCH WILL TURN ON.* OVER CURRENT TO TRANSISTER DRIVING MOTOR AND/OR MAGNETIC CLUTCH.
* WHEN CURRENT CONTINUED TO FLOW TO THE MOTOR INSIDE THE ACTUATOR IN THE THROTTLE VALVE ªOPENº DIRECTION.
* OPEN CIRCUIT IN MAGNETIC CLUTCH.
* MOMENTARY INTERRUPTION OF VEHICLE SPEED SIGNAL.
* SHORT CIRCUIT IN CRUISE CONTROL SWITCH.
* MOTOR DOES NOT OPERATE DESPITE THE MOTOR DRIVE SIGNAL BEING OUTPUT.
B) IF ANY OF THE FOLLOWING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE SET SPEED IS ERASED AND
THE CRUISE CONTROL IS RELEASED. (THE POWER OF MAGNETIC CLUTCH IS CUT OFF U\
NTIL THE SET SWITCH IS ªONº AGAIN.) * WHEN THE VEHICLE SPEED FALLS BELOW THE MINIMUM SPEED LIMIT, APPROX. 40 KM/H ( 2.5 MPH)
* WHEN THE VEHICLE SPEED FALLS MORE THAN 16 KM/H ( 10 MPH) BELOW THE SET SPEED, E.G. ON AN UPWARD SLOPE.
* WHEN POWER TO THE CRUISE CONTROL SYSTEM IS MOMENTARILY CUT OFF.
C) IF ANY OF THE FOLLOWING CONDITIONS OCCURS DURING CRUISE CONTROL OPERATION, THE CRUISE CONTROL IS
RELEASED.
* OPEN CIRCUIT FOR TERMINAL 1 OF CRUISE CONTROL ECU AND SPLICE POINT ªI 9º.
8. AUTOMATIC TRANSMISSION CONTROL FUNCTION
*IN OVERDRIVE. IF THE VEHICLE SPEED BECOMES LOWER THAN THE OVERDRIVE CUT SPEED (SET SPEED MINUS APPROX. 4
KM/H, 2.5 MPH) DURING CRUISE CONTROL OPERATION, SUCH AS DRIVING UP A HILL, THE OVERDRIVE IS RELEASED AND THE
POWER INCREASED TO PREVENT A REDUCTION IN VEHICLE SPEED.
* AFTER RELEASING THE OVERDRIVE, VEHICLE SPEED BECOMES HIGHER THAN THE OVE\
RDRIVE RETURN SPEED (SET SPEED
MINUS APPROX. 2 M/H, 1.2 MPH) AND THE ECU JUDGES BY THE SIGNALS FROM POTENTIOMETER OF THE ACTUATOR THAT THE
UPWARD SLOPE HAS FINISHED, OVERDRIVE IS RESUMED AFTER APPROXIMATELY 6 SECONDS.
* DURING CRUISE CONTROL DRIVING, THE CRUISE CONTROL OPERATION SIGNAL IS OUTPUT FROM THE CRUISE CONTROL
ECU TO THE ENGINE AND TRANSMISSION ECU. UPON RECEIVING THIS SIGNAL, THE ENGIN\
E AND TRANSMISSION ECU
CHANGES THE SHIFT PATTERN TO NORMAL.
TO MAINTAIN SMOOTH CRUISE CONTROL OPERATION (ON A DOWNWARD SLOPE ETC.), LOCK±UP RELEASE OF THE
TRANSMISSION WHEN THE IDLING POINT OF THE THROTTLE POSITION IS ªONº IS FORBIDD\
EN.
C 8 CRUISE CONTROL ACTUATOR
1±3 : APPROX. 2K

5±4 : APPROX. 38.5

C15 CRUISE CONTROL SW [COMB. SW]
15±6 :CONTINUITY WITH MAIN SW ON
5±6 :APPROX. 420
WITH CANCEL SW ON
APPROX. 70
WITH RESUME/ACCEL SW ON
APPROX. 200
WITH SET/COAST SW ON
C19 CRUISE CONTROL ECU
14±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
1, 15±GROUND : ALWAYS APPROX. 12 VOLTS
3±GROUND : CONTINUITY WITH PARKING BRAKE LEVER PULLED UP (ONE OF THE CANCEL SW) OR BRAKE LEVER WARNING SW ON
20±GROUND : 1 PULSE WITH 40CM (DRIVER VEHICLE SLOWLY)
18±GROUND : APPROX. 420
WITH CANCEL SW ON IN CONTROL SW
APPROX. 200
WITH SET/COAST SW ON IN CONTROL SW
APPROX. 70
WITH RESUME/ACCEL SW ON IN CONTROL SW
13±GROUND : ALWAYS CONTINUITY
SERVICE HINTS
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