Lexus LS400 (2000 year). Manual - part 22

I09274

Headrest Motor LH 
(for turning)

Rear Power Seat Switch

Headrest Motor RH 
(for turning)

Headrest Motor RH 
(for vertical)

Headrest Motor LH 
(for vertical)

Slide Motor LH

Slide Motor RH

TAIWAN models:

BE–170

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM (w/o Driving 
Position Memory)

2033

Z16936

Front vertical

Rear vertical

DOWN

UP

BACK

FRONT

Slide

UP

DOWN

BE121–01

Z16937

Reclining

Head Rest

FORWARD

DOWN

UP REAR

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM (w/o Driving 
Position Memory)

BE–171

2034

INSPECTION

1.

INSPECT FRONT POWER SEAT SWITCH CONTINU-
ITY

Slide switch

Switch position

Tester connection

Specified condition

FRONT

11 – 14

12 – 13

Continuity

OFF

11 – 13

12 – 13

Continuity

BACK

11 – 13

12 – 14

Continuity

Front vertical switch

Switch position

Tester connection

Specified condition

UP

9 – 14

10 – 13

Continuity

OFF

9 – 13

10 – 13

Continuity

DOWN

9 – 13

10 – 14

Continuity

Rear vertical switch

Switch position

Tester connection

Specified condition

UP

5 – 14

6 – 13

Continuity

OFF

5 – 13

6 – 13

Continuity

DOWN

5 – 13

6 – 14

Continuity

Reclining switch

Switch position

Tester connection

Specified condition

FORWARD

4 – 14

3 – 13

Continuity

OFF

4 – 13

3 – 13

Continuity

REAR

4 – 13

3 – 14

Continuity

Headrest switch

Switch position

Tester connection

Specified condition

UP

14 – 15

13 – 16

Continuity

OFF

13 – 15

13 – 16

Continuity

DOWN

13 – 15

14 – 16

Continuity

If continuity is not as specified, replace the switch.

Z09315

Wire Harness Side

1

5

11

7

13

2

6

12

8

14

4

10

16

3

9

15

Z07464

FORWARD

RELEASE

BE–172

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM (w/o Driving 
Position Memory)

2035

2.

INSPECT POWER SEAT SWITCH CIRCUIT

(a)

Disconnect the switch connector and connect the seat
wire harness to the floor wire harness.

(b)

Inspect the connector on the wire harness side, as
shown.

Tester connection

Condition

Specified condition

13 – Ground

Constant

Continuity

14 – Ground

Constant

Battery positive voltage

If circuit is not as specified, inspect the circuits connected to oth-
er parts.

3.

INSPECT LUMBAR SUPPORT SWITCH CONTINUITY
( ): Passenger’s Seat

Switch position

Tester connection

Specified condition

FORWARD

1(1) – 4(4)

2(2) – 3(3)

Continuity

OFF

1(2) – 3(3)

2(2) – 3(4)

Continuity

RELEASE

1(1) – 3(3)

2(2) – 4(4)

Continuity

If continuity is not as specified, replace the switch.

Z06678

Wire Harness Side

N07798

2

1

–

+

Z14972

2

1

–

+

–

+

Z07885

2

1

–

+

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM (w/o Driving 
Position Memory)

BE–173

2036

4.

INSPECT LUMBAR SUPPORT SWITCH CIRCUIT

(a)

Disconnect the switch connector and connect the seat
wire harness to the floor wire harness.

(b)

Inspect the connector on the wire harness side, as
shown.

( ): Passenger’s Seat

Tester connection

Condition

Specified condition

3 – Ground (2 – Ground)

Constant

Continuity

4 – Ground (1 – Ground)

Constant

Battery positive voltage

If circuit is not as specified, inspect the circuits connected to oth-
er parts.

5.

INSPECT SLIDE MOTOR OPERATION

(a)

Connect the positive (+) lead from the battery to terminal
2 and the negative (–) lead to terminal 1 and check that
the motor turns counterclockwise.

(b)

Reverse the polarity and check that the motor turns clock-
wise.

If operation is not as specified, replace the motor.

6.

Driver’s seat:
INSPECT SLIDE MOTOR PTC THERMISTOR OPERA-
TION

(a)

Connect the positive (+) lead from the battery to terminal
2, the positive (+) lead from the ammeter to terminal 1,
and the negative (–) lead to battery negative (–) terminal,
then move the seat to front position.

(b)

Continue to apply voltage and check that the current
changes to less than 1 ampere with 4 to 90 seconds.

(c)

Disconnect the lead from terminals.

(d)

Approximately 60 seconds later , connect the positive (+)
lead from battery to terminal 1 and the negative (–) lead
to terminal 2 and check that the seat begins to move back-
wards.

If operation is not as specified, replace the motor.