Lexus GS300/400 (2000 year). Service manual — part 53

I04162

Wire Harness Side

I04161

RELEASE

FORWARD

I04162

Wire Harness Side

BE–170

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM

2471

6.

INSPECT DRIVER’S 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.

Tester connection

Condition

Specified condition

3 – Ground

Constant

Continuity

4 – Ground

Constant

Battery positive voltage

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

7.

INSPECT PASSENGER’S LUMBAR SUPPORT
SWITCH CONTINUITY

Switch position

Tester connection

Specified condition

FORWARD

1 – 4

2 – 3

Continuity

OFF

1 – 3

2 – 3

Continuity

RELEASE

1 – 3

2 – 4

Continuity

If continuity is not as specified, replace the switch.
8.

INSPECT PASSENGER’S 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.

Tester connection

Condition

Specified condition

2 – Ground

Constant

Continuity

1 – Ground

Constant

Battery positive voltage

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

N21865

(a)

(b)

2

1

1

2

N21866

2

1

N21867

2

1

N21865

(a)

(b)

2

1

1

2

N22086

2

1

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM

BE–171

2472

9.

INSPECT SLIDE MOTOR OPERATION

(a)

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

(b)

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

If operation is not as specified, replace the seat adjuster.

10.

INSPECT SLIDE MOTOR PTC THERMISTOR OPERA-
TION
( ): Passenger side

(a)

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

(b)

Continue to apply voltage, check that current changes to
less than 1 ampere within 4 to 90 seconds.

(c)

Disconnect the leads from terminals.

(d)

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

If operation is not as specified, replace the seat adjuster.

11.

INSPECT FRONT VERTICAL MOTOR OPERATION

(a)

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

(b)

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

If operation is not as specified, replace the seat adjuster.

12.

INSPECT FRONT VERTICAL MOTOR PTC THERM-
ISTOR OPERATION
( ): Passenger side

(a)

Connect the positive (+) lead from the battery to terminal
1 (2), the positive (+) lead from the ammeter to terminal
2 (1) and the negative (–) lead to the battery negative (–)
terminal, then move the seat cushion to the highest posi-
tion.

(b)

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

N22087

2

1

N21865

(a)

1

(b)

2

2

1

N22088

2

1

N22089

2

1

N21865

(a)

(b)

2

1

1

2

BE–172

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM

2473

(c)

Disconnect the leads from the terminals.

(d)

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

If operation is not as specified, replace the seat adjuster.

13.

INSPECT LIFTER MOTOR OPERATION

(a)

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

(b)

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

If operation is not as specified, replace the seat adjuster.

14.

INSPECT LIFTER MOTOR PTC THERMISTOR OPERA-
TION

(a)

Connect the positive (+) lead from the battery to terminal
2 (1), the positive (+) lead from the ammeter to terminal
1 (2) and the negative (–) lead to the battery negative (–)
terminal, then move the seat cushion to the highest posi-
tion.

(b)

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

(c)

Disconnect the leads from the terminals.

(d)

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

If operation is not as specified, replace the seat adjuster.

15.

INSPECT RECLINING MOTOR OPERATION

(a)

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

(b)

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

If operation is not as specified, replace the seat adjuster.

N21868

2

1

N21869

2

1

I04163

1

2

I05473

1

2

I04165

2

1

–

BODY ELECTRICAL

POWER SEAT CONTROL SYSTEM

BE–173

2474

16.

INSPECT RECLINING MOTOR PTC THERMISTOR OP-
ERATION

(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 the battery negative (–) terminal,
then recline the seat back to the most forward position.

(b)

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

(c)

Disconnect the leads from the terminals.

(d)

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

If operation is not as specified, replace the seat adjuster.

17.

INSPECT LUMBAR SUPPORT MOTOR OPERATION

(a)

Connect the positive (+) lead from the battery to terminal
1 and the negative (–) lead to terminal 2, check that the
lumbar support moves to release side.

(b)

Reverse the polarity, check that the lumbar support
moves forward.

If operation is not as specified, replace the seat adjuster.

18.

INSPECT LUMBAR SUPPORT MOTOR CIRCUIT
BREAKER OPERATION

(a)

Connect the positive (+) lead from the battery to terminal
2 and the negative (–) lead to terminal 1 on the lumbar
support motor connector and move the lumbar support to
front end position.