LEXUS SC400 1991 Service Repair Manual

163
P 8 POWER SEAT CONTROL SW (FOR DRIVER'S SEAT)
12±GROUND :ALWAYS CONTINUITY 7±GROUND :ALWAYS APPROX. 12 VOLTS
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
P 832P1432P1632
P1332P1532P1732
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1C20FLOOR WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
Ba243FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
BK40UNDER THE CENTER PILLAR LH
1
2
3
4
5
6
7
8
9
10
11
12
X
X 1
2
1
2
12 1
2
P17
P 8 P13, P15 P14 P16 GRAY
SERVICE HINTS
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154
POWER SEAT (w/ DRIVING POSITION MEMORY)
PRND 2 L146578 9
GR
R±B
L
G±W G
W
A/T INDICATOR SW
[NEUTRAL START SW AND BACK±UP LIGHT SW]
N1
IT1
12
1I
10 1H 12
1C
10 1H
1
A
6
STOP A
15
P
A
3 RCL+
A
10 RCL±
B
16 SSRS
B
14 SSRR
B
6 PVCC
B
5 SSFV
B
15 SSRV
2
3 13
1265
2 13 2
13
M
B28
B26 B27
BU1
7
Ba16
Ba1
8 1 2
IJ1
10
GR
V V
V
BR±B
BR±B BR±B
BR±B
BR±B
BR±BLG
V
Y±R Y±B
V
V±W
LG±R V
Y±G V
BR±B
G±W G±W G±W W
Y
GR
GR
Y
Y
VV LG±R
Y±G
V±W
Y±B
Y±R LG
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
15A
STOP 10A
GAUGE
STOP LIGHT
SW
POWER SEAT ECU
(FOR DRIVE R' S SEA T )
SLIDE
POSITION
SENSOR
( FOR
DRIVE R' S SEA T )POWER SEAT MOTOR
(
FOR DRIVER' S SEAT
RECLINING MOTOR
CONTROL ) FRONT
VERTICAL
POSITION
SENSOR
RE AR
VEATICAL
POSITION
SENSOR
S20
P16 F19 R19
P10 , P 1 1
S12
AB
B261
B
( M/T )
PARKING
BRAKE SW
P
3 (
A/T )
BR±B
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155
M
21
M
21
M
21
IH IF
6 3
214
3
12
11
2
1
9
8 3
B
18 SGND
B
8 SI
B
17 SO
A
2
SLD+ A
9
SLD± A
4
FRV+ A
11
FRV± A
13
RRV+ A
12
RRV±
1D
8
1J
1
Ba1
4Ba1 9
Ba2
13 1I
16
1D
10
BT1
11 BT1 12 IF1 12 IF113 IF1 19
BT1
13
BU1
6
IF213
B27
B8
I4 I5
ECUE
BR±B BR±B BR±B P
R
R±Y R±B
L
L±B
L±Y
L±R
Y±G
Y±L
R±W
W±B
W±B BR±B R±B
R±Y
RP
B
W
BR±B
BR±B BR±B BR±B BR±B
WB
B
W
BR±B
BR
BR±B
SI
S O DS W MRY MR M1
P17 P13 P15
P10 ,P1 1
D12
T10
D10 (
SHIELDED )(
SHIELDED)(
SHIELDED )
POWER SEAT MOTOR
(
FOR DRIV ER' S SEA T
SLIDE CONTROL ) POWER SEAT MOTOR
(
FOR DRIVER' S SEAT
FRONT VERTICAL
CONTROL ) POWER SEAT MOTOR
(
FOR DRIV ER' S SEA T
REAR VERTICAL
CONTROL )
POWER SEAT ECU
( FOR DRIVER' S SEAT )
A
B
BR±B
BR±B BR±B
BR±B
DOOR OPEN DE TE CTION S W LH NO. 1
NO. 2
SET
DRIVING POSITION
MEMORY AND
RE TURN SW
TILT AND POWER TELESCOPIC ECU
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156
POWER SEAT (w/ DRIVING POSITION MEMORY)
REARFRONT
M
12
BK
A
8 GND2
A
1 GND
B
1 SLDF
B
9 SLDR
B
3 FUP
B
11 FDWN
B
4 RUP
B
12 RDWN
B
2 RCLF
B
10 RCLR
B
9
SYSB
A
7
IG A
14
+B2 A
+B A
5
1B
5
1C
1
1C
62 1C 81K7
Ba1
12
Ba1
2Ba1 3Ba1 7
B26
B26
11 10
12 56 98 43 12
7
1H
10
14 R
L±W
BR±B L±W
W±B L±W L±W
R
R
R
B±R
R
L±W L±W L±W B±R
W±B W±B
W±B
W±B
W±B BR±B
G
G±R L
L±B
L±Y
L±R
Y±G Y±L
Y±R Y±B
FROM POWER SOURCE SYSTEM (
SEE PAGE 56 )
15A
ECU±IG 10A
DOME 30A
DOOR
FRONT
SLIDE
REA R
UP
FRONT VERTI CAL DOWNUP
DOWN
REAR VERTICAL
FRONT
RECLINING REA R
POWER SEAT CONTROL SW
(FOR DRIV ER' S S EAT )
POWER SEAT MOTOR
(FOR DRIVER' S SEAT
LUMBAR SUPPORT
CONTROL )
LUMBAR
SUPPORT
SW
POWER SEAT ECU
(
FOR DRIVE R' S SE AT )
P8 P14
P10
,P1 1
B
A 1 2
L±W
L±W
6 5
12 3
4
1I
8
BX1
18
Bb1
7
B±R
B±R
B
B
1 2TE NSION REDUCER
SOLENOID RH T1 9
PRDC B
7
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157
2 1
1
2 1
42
3
56 2
134
1 12151310 2 113
86516717 13 2
BX1
4
BX1
17 Bb1
6
Bb1
5 B29 B30
B29
B29
M
12
M
21
BL
Bb1
4
+B SLDF SLDR GND SLD+ SLD±
L±W
W±BBR
BR BR BR
BR
R
L± W
W±B
W±B W±B Y±R
Y±B
L±W L±WL±W
R
BR
B±Y
BR
LG ±R Y
V±W
LGV
L±Y
L±R
W±B L
L±B R
L±W
BR
SYSB PBCL SGND RRSW PFSW SLSW SSRS PVCC
BUCKLE SW
RH
RECLINING LIMIT
SW SLIDE LIMIT
SW
SLIDE POSITION SENSOR
( FOR PASSENGER' S SEAT )
POWER SEAT ECU(
FOR PASSENGER' S SEAT )
POWER SEAT CONTROL SW
( FOR PASSENGER' S SEAT )
POWER SEAT MOTOR
( FOR PASSENGER' S
SEAT RECLINING
CONTROL ) POWER SEAT MOTOR
(
FOR PASSENGER' S
SEAT SLIDE CONTROL )
P12
B5
R20 S19
S21
P9
P18 P19
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158
POWER SEAT (w/ DRIVING POSITION MEMORY)
CURRENT IS ALWAYS APPLIED FROM THE DOME FUSE TO TERMINAL SYSB OF THE POWER SEAT ECU, FROM DOOR FUSE TO
TERMINAL +B OF THE POWER SEAT ECU AND FROM STOP FUSE TO TERMINAL 2 OF THE STOP LIGHT SW.
WHEN THE IGNITION SW IS TURNED ON, CURRENT FLOWS FROM ECU±IG FUSE TO TERMINAL IG OF THE POWER SEAT ECU AND
FROM THE GAUGE FUSE TO TERMINAL 9 OF A/T INDICATOR SW.
POWER SEAT OPERATION (FOR DRIVER'S SEAT)
CURRENT IS ALWAYS APPLIED TO TERMINAL SYSB AND TERMINAL +B OF POWER SEAT ECU SO THAT THE POWER SEAT ECU IS
ALWAYS READY TO OPERATE.
WHEN THE POWER SEAT CONTROL SW IS PUSHED TO THE ªFRONT SIDE POSITIONº SIDE, A SIGNAL IS INPUT INTO TERMINAL
SLDF OF POWER SEAT ECU, THE ECU OPERATES AND THE CURRENT TO TERMINAL +B OF POWER SEAT ECU FLOWS FROM
TERMINAL SLD+ OF POWER SEAT ECU " TERMINAL 2 OF POWER SEAT MOTOR (FOR DRIVER'S SEAT SLIDE CONTROL) " MOTOR
TERMINAL 1 "TERMINAL SLD± OF POWER SEAT ECU "TERMINAL GND "GROUND, ROTATING THE POWER SEAT MOTOR SO
THAT THE SEAT SLIDES FORWARD WHILE THE POWER SEAT CONTROL SW IS BEING PRESSED.
TO SIDE THE DRIVER'S SEAT TO THE REAR, PUSHING THE POWER CONTROL SW TO THE ªREAR SLIDE POSITIONº SIDE, INPUTS A
SIGNAL TO TERMINAL SLDR OF POWER SEAT ECU. THIS CAUSES THE CURRENT FLOWING FROM THE ECU TO THE MOTOR TO
FLOW FROM TERMINAL SLD± OF POWER SEAT ECU " TERMINAL 2 OF POWER SEAT MOTOR (FOR DRIVER'S SEAT SLIDE
CONTROL) "MOTOR " TERMINAL 1 "TERMINAL SLD+ OF POWER SEAT ECU, FLOWING THE REVERSE TO FRONT SLIDE
OPERATION AND CAUSING THE MOTOR TO ROTATE IN REVERSE, SO THAT THE DRIVER'S SEAT MOVES TO THE REAR.
THE MOVEMENT TO OTHER POSITIONS OCCURS SIMILARLY, SO ONLY THE FLOW OF CURRENT TO EACH MOTOR IS SHOWN:
FRONT VERTICAL CONTROL 'UP' OPERATION
TERMINAL +B OF POWER SEAT ECU " TERMINAL FRV+ " TERMINAL 2 OF POWER SEAT MOTOR "MOTOR "TERMINAL 1 "
TERMINAL FRV± OF ECU " TERMINAL GND " GROUND .
FRONT VERTICAL CONTROL 'DOWN' OPERATION
TERMINAL +B OF POWER SEAT ECU " TERMINAL FRV± " TERMINAL 1 OF POWER SEAT MOTOR "MOTOR " TERMINAL 2 "
TERMINAL FRV+ OF ECU " TERMINAL GND " GROUND .
REAR VERTICAL CONTROL 'UP' OPERATION
TERMINAL +B OF POWER SEAT ECU " TERMINAL RRV+ " TERMINAL 2 OF POWER SEAT MOTOR "MOTOR " TERMINAL 1 "
TERMINAL RRV± OF ECU " TERMINAL GND " GROUND .
REAR VERTICAL CONTROL 'DOWN' OPERATION
TERMINAL +B OF POWER SEAT ECU " TERMINAL RRV± " TERMINAL 1 OF POWER SEAT MOTOR " MOTOR " TERMINAL 2 "
TERMINAL RRV+ OF ECU " TERMINAL GND " GROUND .
LUMBAR SUPPORT CONTROL 'FRONT' OPERATION
TERMINAL 7 OF POWER SEAT CONTROL SW " TERMINAL 4 OF LUMBAR SUPPORT SW " TERMINAL 1 " TERMINAL 11 OF POWER
SEAT CONTROL SW " TERMINAL 1 OF POWER SEAT MOTOR " MOTOR " TERMINAL 2 " TERMINAL 10 OF POWER SEAT
CONTROL SW " TERMINAL 2 OF LUMBAR SUPPORT SW "TERMINAL 3 "TERMINAL 12 OF POWER SEAT CONTROL SW "
GROUND .
LUMBAR SUPPORT CONTROL 'REAR' OPERATION
TERMINAL 7 OF POWER SEAT CONTROL SW " TERMINAL 4 OF LUMBAR SUPPORT SW " TERMINAL 2 " TERMINAL 10 OF POWER
SEAT CONTROL SW " TERMINAL 2 OF POWER SEAT MOTOR " MOTOR " TERMINAL 1 " TERMINAL 11 OF POWER SEAT
CONTROL SW " TERMINAL 1 OF LUMBAR SUPPORT SW "TERMINAL 3 "TERMINAL 12 OF POWER SEAT CONTROL SW "
GROUND .
THE NUMBER OF TURNS OF EACH MOTOR (AMOUNT OF MOVEMENT OF EACH PART OF THE SEAT) IS DETECTED BY THE POSITION
SENSORS AND INPUT TO THE ECU, MAKING IT POSSIBLE TO PERFORM MEMORY AND RETURN FUNCTIONS FOR THE SEAT
POSITION USING THE DRIVING POSITION MEMORY AND RETURN SWITCH.
POWER WALK±IN OPERATION (FOR PASSENGER'S SEAT)
WALK±IN OPERATION
WHEN THE WALK±IN PEDAL IS DEPRESSED OR THE RECLINING HANDLE IS LIFTED UP, THE SEAT BACK RECLINES FULLY
FORWARD AND RECLINING LIMIT SWITCH NO. 2 OPERATES, SO A SIGNAL IS INPUT TO TERMINAL RFSW OF THE POWER SEAT ECU
" TERMINAL SLD+ " TERMINAL 1 OF THE POWER SEAT MOTOR (FOR PASSENGER'S SEAT SLIDE CONTROL) " MOTOR "
TERMINAL 2 " TERMINAL SLD± OF THE ECU "TERMINAL GND " GROUND . THIS CAUSES THE SEAT TO SLIDE FORWARD 100 MM
IN THE WALK±IN MODE. HOWEVER, WHEN THE INITIAL SLIDE POSITION IS 100 MM OR LESS FROM THE MOST FORE POSITION, THE
SEAT CAN ONLY SLIDE FORWARD AS FAR AS THE MOST FORE POSITION.
SYSTEM OUTLINE
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159
RETURN OPERATION
WHEN THE SEAT BACK IS RAISED UP FROM THE WALK±IN POSITION AND RETURNED TO THE UPRIGHT LOCK POSITION,
RECLINING LIMIT SWITCH NO. 1 OPERATES AND A SIGNAL IS INPUT TO TERMINAL RRSW OF THE POWER SEAT ECU " TERMINAL
SLD± " TERMINAL 2 OF POWER SEAT MOTOR (FOR PASSENGER'S SEAT SLIDE CONTROL) " MOTOR " TERMINAL 1 " TERMINAL
SLD+ OF ECU " TERMINAL GND " GROUND . THIS CAUSES THE SEAT TO SLIDE BACK TO A POSITION 120 MM FROM THE MOST
REAR POSITION, COMPLETING RETURN OPERATION. HOWEVER, IF THE SEAT IS POSITIONED WITHIN 120 MM OF THE MOST REAR
POSITION, RETURN OPERATION DOES NOT OCCUR, THUS MAINTAINING SUFFICIENT SPACE FOR THE REAR SEAT PASSENGER.
D10 DOOR LOCK MOTOR, DOOR UNLOCK DETECTION SW AND DOOR OPEN DETECTION SW LH
3±6 : CLOSED WITH FRONT LH DOOR OPEN
N 1 A/T INDICATOR SW [NEUTRAL START SW]
9±1 : CLOSED WITH SHIFT LEVER AT ªPº POSITION
P10(A), P11(B) POWER SEAT ECU (FOR DRIVER'S SEAT)
(A) 6±GROUND : APPROX. 12 VOLTS WITH STOP LIGHT SW ON
(B) 7±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 7±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON
(A) 15±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON AND SHIFT LEVER AT ªPº RANGE
(A) 2±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT FRONT SLIDE OPERATION
(A) 9±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT REAR SLIDE OPERATION
(A) 4±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT FRONT VERTICAL UP OPERATION
(A) 11±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT FRONT VERTICAL DOWN OPERATION
(A) 13±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT REAR VERTICAL UP OPERATION
(A) 12±GROUND : APPROX. 12 VOLTS WITH DRIVER'S SEAT AT REAR VERTICAL DOWN OPERATION
(B) 18±GROUND : ALWAYS CONTINUITY
(A) 5, (A) 14±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 1, (A) 8±GROUND : ALWAYS CONTINUITY
P 8 POWER SEAT CONTROL SW (FOR DRIVER'S SEAT)
4±14 : CLOSED WITH DRIVER'S SEAT AT FRONT RECLINING OPERATION
3±14 : CLOSED WITH DRIVER'S SEAT AT REAR RECLINING OPERATION
1±14 : CLOSED WITH DRIVER'S SEAT AT FRONT SLIDE OPERATION
2±14 : CLOSED WITH DRIVER'S SEAT AT REAR SLIDE OPERATION
5±14 : CLOSED WITH DRIVER'S SEAT AT FRONT VERTICAL UP OPERATION
6±14 : CLOSED WITH DRIVER'S SEAT AT FRONT VERTICAL DOWN OPERATION
9±14 : CLOSED WITH DRIVER'S SEAT AT REAR VERTICAL UP OPERATION
8±14 : CLOSED WITH DRIVER'S SEAT AT REAR VERTICAL DOWN OPERATION
P12 POWER SEAT ECU (FOR PASSENGER'S SEAT)
1±GROUND : ALWAYS APPROX. 12 VOLTS
8±GROUND : ALWAYS APPROX. 12 VOLTS
7±GROUND : APPROX. 12 VOLTS WITH PASSENGER'S SEAT AT FRONT SLIDE OPERATION
17±GROUND : APPROX. 12 VOLTS WITH PASSENGER'S SEAT AT REAR SLIDE OPERATION
S12 STOP LIGHT SW
2±1 : CLOSED WITH STOP LIGHT SW ON
SERVICE HINTS
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160
POWER SEAT (w/ DRIVING POSITION MEMORY)
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
B532P11B32R1932
D1030P1232R2032
D1230P1332S1232
F1932P1432S1932
N 127P1532S2029
P 329P1632S2132
P 832P1732T1029
P 932P1832T1931
P10A32P1932
: 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
1C20FLOOR 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)
IF136FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)IF236FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IT138ENGINE WIRE AND A/C WIRE (BEHIND GLOVE BOX)
BT140FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)
BU140FLOOR WIRE AND INSTRUMENT PANEL WIRE (LEFT KICK PANEL)
BX140FLOOR NO. 3 WIRE AND COWL WIRE (RIGHT KICK PANEL)
Ba142FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)Ba242FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)
Bb142FLOOR NO. 3 WIRE AND FRONT SEAT RH WIRE (UNDER THE FRONT RH SEAT)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
IH36UNDER THE ASHTRAY LH
BK40UNDER THE CENTER PILLAR LH
BL40UNDER THE CENTER PILLAR RH
: SPLICE POINTS
CODESEE PAGEWIRE HARNESS WITH SPLICE POINTSCODESEE PAGEWIRE HARNESS WITH SPLICE POINTS
I 438COWL WIREB2742FRONT SEAT LH WIREI 538COWL WIREB2842FRONT SEAT LH WIRE
B 840FLOOR MAIN WIREB2942FRONT SEAT RH WIREB2642FRONT SEAT LH WIREB3042FRONT SEAT RH WIRE
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161
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164POWER TILT AND POWER TELESCOPIC
1H
15 1K 13 2
1H
10 1B
5
AAB
B±R
L±W
RR
30A
POWER 15A
ECU±IG10A
DOME
4118 +B I G ECU ± B TILT AND POWER TELESCOPIC ECU
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
BA,T11
T10
1
1
A
7B 10 B 1B9B 8B 3B12 B 11
IF IH
I5
I5
B27
BT1
12 BT1 11
BT1
13 IF2 13 IF119 IF1 13 IF212
Ba1
9Ba1 4
1H
13
1J
1 9
10
18
178 3214
B9
1D
10 BU1
6
GN D UWSW SO
SI ECU±E M1 M2 MRY
BR±B
W±B
B W
Y
W±B
W±B
BR±B
BR±B
BR±B
B
W
B
W
BR±B
BR±B
BR±B
BR BR±B
P
R
R±Y
R±Y R P
BR±B
W±B
W±B
SSR±
SO SI
UNLOCK WARNING SW
[IGNITION SW]
POWER SEAT ECU
DRIV ING POSITION MEMORY
AND RETURN SW
(
SHIELDED )
(
SHIELDED )
(
SHIELDED )
NO. 1
NO. 2SET
P11
I15
D12
Ba1
13 2
B8
I3
BR±B
W
BR±B16
SI
REMOTE CONTROL
MIRROR ECU R7
W
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