Lexus SC300 / Lexus SC400. Manual - part 1004

157

2

1

1

2

1

4

2

3

5

6

2

1

3

4

1

12

15

13

10

2

11

3

8

6

5

16

7

17

1

3

2

BX1

4

BX1

17

Bb1

6

Bb1

5

B29

B30

B29

B29

M

1

2

M

2

1

BL

Bb1

4

+B

SLDF

SLDR

GND

SLD+

SLD–

L–W

W–B

BR

BR

BR

BR

BR

R

L–W

W–

B

W–

B

W

–

B

Y–

R

Y–

B

L–W

L–W

L–W

R

BR

B–

Y

BR

LG

–

R

Y

V–

W

LG

V

L–

Y

L–R

W–

B

L

L–

B

R

L–W

BR

SYSB

PBCL

SGND

RRSW

PFSW

SLSW

SSRS

PVCC

B

UCK

L

E

S

W

RH

RE

CLIN

ING

L

IM

IT

SW

S

L

ID

E

L

IM

IT

SW

S

L

IDE

P

O

S

IT

IO

N

S

E

N

S

O

R

(F

O

R

P

AS

SE

N

G

ER

’

S

SE

AT

)

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

R2

0

S1

9

S2

1

P 9

P18

P19

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 “FRONT SIDE POSITION” 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 “REAR SLIDE POSITION” 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

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 “P” 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 “P” 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

160

POWER SEAT (w/ DRIVING POSITION MEMORY)

: PARTS LOCATION

CODE

SEE PAGE

CODE

SEE PAGE

CODE

SEE PAGE

B 5

32

P11

B

32

R19

32

D10

30

P12

32

R20

32

D12

30

P13

32

S12

32

F19

32

P14

32

S19

32

N 1

27

P15

32

S20

29

P 3

29

P16

32

S21

32

P 8

32

P17

32

T10

29

P 9

32

P18

32

T19

31

P10

A

32

P19

32

: RELAY BLOCKS

CODE

SEE PAGE

RELAY BLOCKS (RELAY BLOCK LOCATION)

2

19

ENGINE COMPARTMENT LEFT

: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR

CODE

SEE PAGE

JUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)

1B

20

ENGINE ROOM MAIN WIRE

1C

20

FLOOR WIRE

1D

20

FRONT DOOR LH WIRE

1H

1I

20

COWL WIRE

1J

20

COWL WIRE

1K

: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS

CODE

SEE PAGE

JOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)

IF1

36

FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)

IF2

36

FRONT DOOR LH WIRE AND COWL WIRE (LEFT KICK PANEL)

IJ1

36

ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)

IT1

38

ENGINE WIRE AND A/C WIRE (BEHIND GLOVE BOX)

BT1

40

FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)

BU1

40

FLOOR WIRE AND INSTRUMENT PANEL WIRE (LEFT KICK PANEL)

BX1

40

FLOOR NO. 3 WIRE AND COWL WIRE (RIGHT KICK PANEL)

Ba1

42

FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)

Ba2

42

FLOOR WIRE AND FRONT SEAT LH WIRE (UNDER THE FRONT LH SEAT)

Bb1

42

FLOOR NO. 3 WIRE AND FRONT SEAT RH WIRE (UNDER THE FRONT RH SEAT)

: GROUND POINTS

CODE

SEE PAGE

GROUND POINTS LOCATION

IF

36

LEFT KICK PANEL

IH

36

UNDER THE ASHTRAY LH

BK

40

UNDER THE CENTER PILLAR LH

BL

40

UNDER THE CENTER PILLAR RH

: SPLICE POINTS

CODE

SEE PAGE

WIRE HARNESS WITH SPLICE POINTS

CODE

SEE PAGE

WIRE HARNESS WITH SPLICE POINTS

I 4

38

COWL WIRE

B27

42

FRONT SEAT LH WIRE

I 5

38

COWL WIRE

B28

42

FRONT SEAT LH WIRE

B 8

40

FLOOR MAIN WIRE

B29

42

FRONT SEAT RH WIRE

B26

42

FRONT SEAT LH WIRE

B30

42

FRONT SEAT RH WIRE