LEXUS SC400 1991 Service Repair Manual

56
POWER SOURCE
AM2 AM1
ACC
IG 1
IG 2
321 6 411
ST1
1B
2
1J 5
1J 6
1J 3
1J 8 1K
13
1K 4
1J
4
1B
4
1J
7 I24
I33
I11 P
N 2
3
IE1
16
IJ16
3421314 59 7
116
W
WB
B
B
B±R
B±W B±W
W±L
B
B±O P±L B
B
B
W±L R
W±R
W±R
B
W±R Y
W±L
W±R
W
W±R
B±Y
B±W P±L
B±O
B±W
B±W
B±W
B±WW
B±R
15A ECU±B
15A STOP
30A POWER
30A DOOR
TAILLIGHT
RELAY 15A TAIL
7. 5A PANEL BATTERY
15A ECU±IG
7. 5A ENGINE
20A W IPER
10A GAUGE 20A TURN
10A HEATER
7. 5A ST
7. 5A IGN 15A CIG
7. 5A RADIO NO. 2
40A
IGSW
NEUTRAL
START SW
TO ENGINE AND ECT ECUTO CRUISE CONTROL ECU
TO ABS ACTUATOR RELAY,
ABS MOTOR RELAY AND
TRACTION BRAKE
ACTUATOR RELAYTO ALTERNATOR º Bº
IGNITION SW
FUSE BLOCK
TO TRACTION MOTOR RELAY100A AM1
60A ABS NO. 1
30A INJ
120A ALT 30A AM2
30A ABS NO. 2 60A MAIN
F9
N1
I15
5
1 3
2
2
6
3 4 1
5
1 2IJ2
8 B
B±W
B
B
(
M/T )
(
M/T )
C23
CLUTCH START SW
(
A/T )
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57
87
65
43
21
10 9
12 11
14 13
21
22 21
20 19
18 17
16 15
2
2
2
2
2
2
2
2
2
2
2 2 22
2
2
2
2
2
22
2 2
2
IF 4
1B
1
4
4 2
2
4
4
EB1
3
W
B
B
B
B±R R±L
B
B
L±O R±Y L±R
WR
B±Y W
L±Y
W±L R
R
R
R±G R±B
R±W
B
R±Y
B
B
B±R
2
B
W±B B
R
1
212
1 2
2
4
3
1
1
3 43
1
3
5
2
2
4 4
3
5
3
4
20A RADIO NO. 1
25A HAZ±HORN 30A EFI
10A DOME
15A TEL
7. 5A ALT SENCING 7. 5A TRAC
HEADLIGHT
RELAY STARTER
RELAY
60A HEATER
50A DEFOGGER DEFOGGER
RE LA Y
15A SEAT±HTR
15A HEAD
(
LH±UPR )
15A HEAD (
RH±UPR )
15A HEAD (
LH )(
FOR USA )
15A HEAD (
LH±LWR )(
FOR CANADA )
15A HEAD (
RH )(
FOR USA )
15A HEAD (
RH±LWR )(
FOR CANADA )
DIMMER
RELAY
SEAT HEATER
RELAY 10A MIR±HTR
W±B I1W±B
B
(
M/T )
( A/T )
( CA NA DA )
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58
POWER SOURCE
HEADLIGHT RELAY (FOR USA)1±2 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION OR DIMMER SW AT FLASH POSITION
HEADLIGHT RELAY (FOR CANADA) 1±2 : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION OR DIMMER SW AT FLASH POSITION
: CLOSED WITH ENGINE RUNNING AND PARKING BRAKE PEDAL RELEASED (PARKING BRAKE SW OFF)
TAILLIGHT RELAY (FOR USA) 5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
TAILLIGHT RELAY (FOR CANADA) 5±3 : CLOSED WITH LIGHT CONTROL SW AT TAIL OR HEAD POSITION
: CLOSED WITH ENGINE RUNNING AND PARKING BRAKE PEDAL RELEASED (PARKING BRAKE SW OFF)
IGNITION MAIN RELAY 2±1 : CLOSED WITH IGNITION KEY AT ON OR ST POSITION
I15 IGNITION SW
4±3 : CLOSED WITH IGNITION KEY AT ACC OR ON POSITION
4±2 : CLOSED WITH IGNITION KEY AT ON OR ST POSITION
11±6: CLOSED WITH IGNITION KEY AT ON OR ST POSITION
4±1 : CLOSED WITH IGNITION KEY AT ST POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C2328I1529
F 926N 127
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
423LEFT KICK PANEL (J/B NO.1 LEFT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1J20COWL WIRE1K20COWL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
EB134ENGINE WIRE AND ENGINE ROOM MAIN WIRE (FRONT SIDE OF R/B NO. 2)
IE136ENGINE ROOM MAIN WIRE AND COWL WIRE (R/B NO. 4)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 138COWL WIREI2438ENGINE ROOM MAIN WIRE
I1138COWL WIREI3338ENGINE WIRE
SERVICE HINTS
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122
POWER WINDOW
2
1H
10
1D
8 1J
11D 10 1D 91J 2
1B
5
1I
16
6 3 6
3
IF IJ IP1
20 IP1
15
B4 8
31
1I
7
24
A
20 A 8A2
A
16 A 13 A12 4
B 8
R
R
L±WB±R
W±B
W±B L
LW±B
R±B
R±W
W±B
W±B
W±B
W±B R±W
R±W
W±B
W±B
W±B
L
R±W
R±W
L
W±B W±B Y±R
10A
DOME
30A
DOOR15A
ECU±IG 30A
POWER
KEY OFF POWER
CIRCUIT POWER
MAIN
RELAY
DOOR OPEN
DE TE CTION SW RHDOOR OPEN
DE TECTION S W LH
THEFT DETERRENT
AND DOOR LOCK ECU
POWERWINDOWMASTERAND
DOOR LOCK CONTROL SW LH
DOOR LOCK
T8 ,T9
B A
1 2
1K
71K 13
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
D10
D11
P5
62
51
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123
UP
DOWN
M
UP
DOWN
3
42 IP1
2
IP1
3
IP1
11 IF2
11 IF2 3
M
21
910 5 7
51
R±L
G±W
R±L
G±W
G±Y
R
R
G±Y R±L
G±W L L
L L
POWER WINDOW MASTER AND
DOOR LOCK CONTROL SW LH
DRIVER' S PASSENGER' S
LH RH
DOWNAUTO UP
LOCK
NORMAL
S
R
Q
12
POWER WINDOW
CONTROL SW RH
POWER WINDOW
MOTOR RH
POWER WINDOW
MOTOR LH P7
P6
P4
P5
±
+
±
+
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124
POWER WINDOW
WITH THE IGNITION SW TURNED ON, CURRENT FLOWS THROUGH THE ECU±IG FUSE " TERMINAL (A)2 OF THE THEFT
DETERRENT ECU " (B)8 " TERMINAL 2 OF THE POWER MAIN RELAY " TERMINAL 3 " TO GROUND, THIS ACTIVATES THE RELAY
AND THE CURRENT FLOWING TO TERMINAL 4 OF THE RELAY FROM POWER FUSE FLOWS TO TERMINAL 1 OF THE RELAY "
TERMINAL 4 OF THE POWER WINDOW MASTER SW, TERMINAL 3 OF THE POWER WINDOW SW.
1. MANUAL OPERATION (DRIVER'S WINDOW)
WITH THE IGNITION SW TURNED ON AND WITH THE POWER WINDOW MASTER SW (DRIVER'S) IN UP POSITION, THE CURRENT
FLOWING TO TERMINAL 4 OF THE POWER WINDOW MASTER SW FLOWS TO TERMINAL 10 OF THE MASTER SW " TERMINAL 1 OF
THE POWER WINDOW MOTOR " TERMINAL 2 " TERMINAL 9 OF THE MASTER SW " TERMINAL 8 " TO GROUND AND CAUSES
THE POWER WINDOW MOTOR TO ROTATE IN THE UP DIRECTION. THE WINDOW ASCENDS ONLY WHILE THE SW IS BEING PUSHED.
IN DOWN OPERATION, THE FLOW OF CURRENT FROM TERMINAL 4 OF THE POWER WINDOW MASTER SW TO TERMINAL 9 OF THE
MASTER SW CAUSES THE FLOW OF CURRENT FROM TERMINAL 2 OF THE MOTOR " TERMINAL 1 " TERMINAL 10 OF THE
MASTER SW " TERMINAL 8 " TO GROUND, FLOWING IN THE OPPOSITE DIRECTION TO MANUAL UP OPERATION AND CAUSING
THE MOTOR TO ROTATE IN REVERSE, LOWERING THE WINDOW.
2. DRIVER'S WINDOW AUTO DOWN OPERATION
WHEN THE DRIVER'S WINDOW SW IS PUSHED STRONGLY ON THE DOWN SIDE, THE CURRENT FLOWING TO TERMINAL 4 OF THE
POWER WINDOW MASTER SW FLOWS TO THE DOWN CONTACT POINT AND AUTO DOWN CONTACT POINT OF THE DRIVER'S SW.
THIS ACTIVATES THE RELAY (DOWN SIDE) INSIDE THE POWER WINDOW MASTER SW AND THE HOLD CIRCUIT ALSO TURNS ON AT
THE SAME TIME, SO THE RELAY (DOWN SIDE) REMAINS ACTIVATED EVEN WHEN THE SW IS RELEASED.
CURRENT FLOWS AT THIS TIME FROM TERMINAL 4 OF THE POWER WINDOW MASTER SW " TERMINAL 9 " TERMINAL 2 OF
POWER WINDOW MOTOR " MOTOR " TERMINAL 1 " TERMINAL 10 OF POWER WINDOW MASTER SW " TERMINAL 8 " GROUND,
SO THE MOTOR CONTINUES TO OPERATE UNTIL THE DRIVER'S WINDOW IS FULLY DOWN.
WHEN THE DRIVER'S WINDOW FINISHES DOWN OPERATION THE HOLD CIRCUIT GOES OFF, SO THE RELAY (DOWN SIDE) ALSO
TURNS OFF. THIS STOPS THE CURRENT FLOW FROM TERMINAL 4 OF THE POWER WINDOW MASTER SW TO TERMINAL 9, SO THE
POWER WINDOW MOTOR STOPS AND AUTO DOWN OPERATION STOPS.
WHEN THE DRIVER'S SW IS PULLED ON THE UP SIDE DURING AUTO DOWN OPERATION, THE HOLD CIRCUIT IS TURNED OFF SO
CURRENT FLOW FROM TERMINAL 4 OF THE POWER WINDOW MASTER SW TO TERMINAL 9 IS CUT OFF AND THE POWER WINDOW
MOTOR STOPS. IF THE SW REMAINS PULLED UP THE RELAY (UP SIDE) IS ACTIVATED, SO CURRENT FLOWS FROM TERMINAL 4 OF
THE POWER WINDOW MASTER SW " TERMINAL 10 " TERMINAL 1 OF POWER WINDOW MOTOR " MOTOR " TERMINAL 2 "
TERMINAL 9 " TERMINAL 8 " GROUND, THE POWER WINDOW MOTOR ROTATES IN THE UP DIRECTION AND MANUAL UP
OPERATION OCCURS WHILE THE SWITCH IS PULLED UP.
3. MANUAL OPERATION BY POWER WINDOW SW (PASSENGER'S WINDOW)
WITH POWER WINDOW SW (PASSENGER'S) PULLED TO THE UP SIDE, CURRENT FLOWING FROM TERMINAL 3 OF THE POWER
WINDOW CONTROL SW FLOWS TO TERMINAL 5 OF THE POWER WINDOW SW " TERMINAL 1 OF THE POWER WINDOW MOTOR "
TERMINAL 2 " TERMINAL 1 OF THE POWER WINDOW SW " TERMINAL 2 " TERMINAL 7 OF THE MASTER SW " TERMINAL 8 " TO
GROUND AND CAUSES THE POWER WINDOW MOTOR (PASSENGER'S) TO ROTATE IN THE UP DIRECTION. UP OPERATION
CONTINUES ONLY WHILE THE POWER WINDOW SW IS PULLED TO THE UP SIDE. WHEN THE WINDOW DESCENDS, THE CURRENT
FLOWING TO THE MOTOR FLOWS IN THE OPPOSITE DIRECTION, FROM TERMINAL 2 TO TERMINAL 1, AND THE MOTOR ROTATES IN
REVERSE. WHEN THE WINDOW LOCK SW IS PUSHED TO THE LOCK SIDE, THE GROUND CIRCUIT TO THE PASSENGER'S WINDOW
BECOMES OPEN.
AS A RESULT, EVEN IF OPEN/CLOSE OPERATION OF THE PASSENGER'S WINDOW IS TRIED, THE CURRENT FROM TERMINAL 8 OF
THE POWER WINDOW MASTER SW IS NOT GROUNDED AND THE MOTOR DOES NOT ROTATE, SO THE PASSENGER'S WINDOW CAN
NOT BE OPERATED AND WINDOW LOCK OCCURS.
4. KEY OFF POWER WINDOW OPERATION
WITH THE IGNITION SW TURNED FROM ON TO OFF, THE THEFT DETERRENT ECU OPERATES AND CURRENT FLOWS FROM DOOR
FUSE TO TERMINAL (A)8 OF THE ECU OR DOME FUSE TO TERMINAL (A)20 OF THE ECU " TERMINAL (B)8 " TERMINAL 2 OF
POWER MAIN RELAY " TERMINAL 3 " TO GROUND FOR ABOUT 60 SECONDS. THE SAME AS NORMAL OPERATION, THE CURRENT
FLOWS FROM POWER FUSE " TERMINAL 4 OF THE POWER MAIN RELAY " TERMINAL 1 " TERMINAL 4 OF THE POWER WINDOW
MASTER SW AND TERMINAL 5 OF THE POWER WINDOW SW. AS A RESULT, FOR ABOUT 60 SECONDS AFTER THE IGNITION SW IS
TURNED OFF, THE FUNCTIONING OF THIS RELAY MAKES IT POSSIBLE TO RAISE AND LOWER THE POWER WINDOW. ALSO, BY
OPENING THE FRONT DOOR (DOOR DETECT SW ON) WITHIN ABOUT 60 SECONDS AFTER TURNING THE IGNITION SW TO OFF, A
SIGNAL IS INPUT TO TERMINALS (A)12 OR (A)13 OF THEFT DETERRENT ECU. AS A RESULT, THE ECU TURNS OFF AND UP AND
DOWN MOVEMENT OF THE POWER WINDOW STOPS.
SYSTEM OUTLINE
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125
P 5 POWER WINDOW MASTER AND DOOR LOCK CONTROL SW LH
4±GROUND: APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
8±GROUND: ALWAYS CONTINUITY
10±GROUND: APPROX. 12 VOLTS WITH IGNITION SW ON AND MASTER SW (DRIVER'S WINDOW) AT UP POSITION
9±GROUND: APPROX. 12 VOLTS WITH IGNITION SW ON AND MASTER SW (DRIVER'S WINDOW) AT DOWN OR AUTO DOWN
POSITION
WINDOW LOCK SW
OPEN WITH WINDOW LOCK SW AT LOCK POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
D1029P 529T 8B29
D1129P 629T 9A29
P 429P 729
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1D20FRONT DOOR LH WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IF236FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)
IP138FRONT DOOR RH WIRE AND COWL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
IJ36RIGHT KICK PANEL
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
B 440FRONT DOOR LH WIRE
SERVICE HINTS
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186
PPS (PROGRESSIVE POWER STEERING)
1H
12 1E 12 1I
9
IJ1
10
IK1
7IK1 6IG2
7
IJ2
6IJ2 16
12
10A
GAUGE
15A
E CU±IG
COMBINATION METER SPEED
SENSOR
NO. 1 PPS SOLENOID
PPS ECU
321 5 4
2
3
1 OUT
VCC GN D
Y SPD E SOL+ SOL±
+B
B±RY Y
PP W±BLG±B
LG±R
LG±B
LG±R
W±B
R
R L±R
Y
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
S3 P1
P2
C14
BR
13 15 10 1143D
13 3A
4
Y
IH IJ
B
2
A
2 SHORT
CONNECTOR
L±R L±R
S22 , S 2 3
BA
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11015
14
13 12
12345 123
GRAY GRAY
C14 P 1 P 2 S 3
X
2 2
BA
S22 S23
187
THE PPS (HYDRAULIC REACTION TYPE) CONTROLS THE HYDRAULIC PRESSURE APPLIED\
TO THE HYDRAULIC REACTION
CHAMBER IN THE GEAR BOX CONTROL UNIT USING THE PPS ECU, TO CHANGE THE STEERING FORCE AND PROVIDE OPTIMUM
STEERING FEELING AT ANY VEHICLE SPEED AND UNDER ANY STEERING CONDITIONS.
(PPS OPERATION)
WHEN THE IGNITION SW IS TURNED ON THE STARTING CURRENT FLOWS FROM THE ECU±IG FUSE TO TERMINAL 4 OF THE PPS
ECU. THE SPEED SENSOR MONITORS THE VEHICLE SPEED AND TRANSMITS CONTROL SIGNALS TO TERMINAL 3 OF THE ECU.
WHEN THE VEHICLE SPEED IS LOW, THE PPS ECU SENDS A HIGHER±VOLTAGE FROM TERMINAL 1 OF THE ECU " TERMINAL 1 OF
THE SOLENOID VALVE " TERMINAL 2 " TERMINAL 5 OF THE ECU " TERMINAL 2 " GROUND, INCREASING THE SOLENOID VALVE
OPENING ANGLE TO PROVIDE COMFORTABLE STEERING OPERATION. WHEN THE VEHICLE SPEED IS HIGH, THE PPS ECU
DECREASES THE SOLENOID VALVE OPENING ANGLE BY REDUCING THE VOLTAGE TO THE VALVE TO PROVIDE RESPONSIVE
STEERING FEELING.
P 1 PPS SOLENOID
1±2 : APPROX. 7.7
(25 °C, 77°F)
P 2 PPS ECU
4±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
2±GROUND : ALWAYS CONTINUITY
1±5 : APPROX. 0.8A WITH VEHICLE SPEED BELOW 20 KM/H ( 12 MPH)
APPROX. 0.45A WITH VEHICLE SPEED AT 80 KM/H ( 48 MPH)
APPROX. 0.2A WITH VEHICLE SPEED ABOVE 160 KM/H ( 96 MPH)
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1428P 229S22B29
P 127S 327S23A29
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE
1H20COWL WIRE1I20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG236INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IK136ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IH36UNDER THE ASHTRAY LH
IJ36RIGHT KICK PANEL
SYSTEM OUTLINE
SERVICE HINTS
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162
POWER SEAT (w/o DRIVING POSITION MEMORY)
FROM POWER SOURCE SYSTEM(
SEE PAGE 56 )
30A
DOOR
1C
8
Ba2
4
BK
Ba2
5
POWER SEAT CONTROL SW
(
FOR DRIVER' S SEAT )
REARFRONT
HOLD RE LEA SE
12
12
7
UP
DOWN FRONT
REAR UP
DOWN
5643981011 P8
M
12
M
21
M
21
M
21
M
21
G±R
GL
L±B
L±Y
L±R
Y±R
Y±B
Y±G
Y±L L±W
L±W
W±B
W±B
POWER SEAT MOTOR
(
FOR DRIVE R' S SE AT
SLIDE CONTROL )POWER SEAT MOTOR
(
FOR DRIVER' S SEAT
FRONT VERTI CA L
CONTROL ) POWER SEAT MOTOR
(
FOR DRIVE R' S SE AT
RECLINING MOTOR
CONTROL ) POWER SEAT MOTOR
(
FOR DRIVER' S SEAT
REAR VERTICAL
CONTROL ) POWER SEAT MOTOR
(
FOR DRIVE R' S SE AT
LUMBAR SUPPORT
CONTROL )
P17 P13 P16 P15 P14 SLIDE FRONT VERTICAL RECLINING REAR VERTICAL LUMBAR SUPPORT
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