Lexus SC300 / Lexus SC400. Manual — part 135

2.

INSPECT BRAKE WARNING LIGHT
(a) Disconnect the connector from the brake fluid warning

switch.

(b) Release the parking brake pedal.
(c) Connect terminals on the wire harness side of the level

warning switch connector.

(d) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or wire har-
ness.

(Parking Brake Switch)

REMOVAL AND INSTALLATION OF PARKING
BRAKE SWITCH

1.

REMOVE PARKING BRAKE SWITCH
(a) Remove the driver’s seat.
(See page

BO–58

)

(b) Disconnect the connector and remove switch.

2.

INSTALL PARKING BRAKE SWITCH
For installation follow the removal procedure in reverse.

INSPECTION OF PARKING BRAKE SWITCH

1.

INSPECT PARKING BRAKE SWITCH
(a) Check that there is continuity between terminal and

switch body with the switch ON (switch pin released).

(b) Check that there is no continuity between terminal and

switch body with the switch OFF (switch pin pushed in.)

If continuity is not as specified, replace the switch or inspect
ground point.

2.

INSPECT BRAKE WARNING LIGHT
(a) Disconnect the connector from the parking brake switch

and brake fluid warning switch.

(b) Ground terminal on the wire harness side connector.
(c) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect
wire harness.

BE–116

–

BODY ELECTRICAL SYSTEM

Combination Meter

( Coolant Level Warning Switch)

REMOVAL AND INSTALLATION OF COOLANT
LEVEL WARNING SWITCH

1.

REMOVE COOLANT LEVEL WARNING SWITCH
(a) Disconnect the connector.
(b) Remove the boot.
(c) Using the notches in the head of switch, turn the switch

counterclockwise and remove it.

NOTICE: Do not remove when engine is hot.

2.

INSTALL COOLANT LEVEL WARNING SWITCH
For installation, follow the removal procedure in reverse.

INSPECTION OF COOLANT LEVEL WARNING
SWITCH

1.

INSPECT COOLANT LEVEL WARNING SWITCH
(Continuity)
(a) Remove the radiator cap and open the radiator drain

clock.

NOTICE: Do not remove when engine is hot.
(b) Drain the coolant about 1 liter.

(1.1 US qts, 0.9 lmp. qts)

(c) Check that there is continuity between terminals (float

down).

(d) Close radiator drain cock and fill the cooling system with

coolant.

(e) Check that there is no continuity between terminals

(float up).

If continuity is not as specified, replace the switch.

2.

INSPECT COOLANT LEVEL WARNING LIGHT
(a) Disconnect

the connector from the coolant level warning

switch and ground terminal 1 on the wire harness side
connector.

(b) Start the engine, check that the warning light lights up.
If the warning light does not light up, inspect the bulb or wire
harness.

–

BODY ELECTRICAL SYSTEM

Combination Meter

BE–117

POWER WINDOW CONTROL
SYSTEM

Description

The Power Window System raises and lowers the window glass in each door using electrical power. The compo-
nent parts of this system and their functions are described in the following table.

Parts Name

Function

Theft Deterrent and
Door Lock
Control ECU

Current is sent to the power window main relay only when the ignition switch
is on or within a specified period after the ignition switch is turned off.

Power Window
Main Relay

Current from the theft deterrent and door lock control ECU to the power
window main relay switches large current from the master switch ON and OFF.

Master Switch

This switch turns current to each power window motor ON and OFF and
switches it. It also includes a circuit for ”One Touch Power Window” use of
the driver’s window and a built–in window lock switch which controls the
operation of all power window switches.

Power Window
Switch

This switch is installed on each door except on the driver’s door. It is supplied
with current from the master siwtch and turns the current to the motor ON and
OFF and switches the current. This switch will not operate when the window
lock switch inside the master switch is in the LOCK position.

Power Window
Motor

This motor moves the window regulator directly when current is supplied to it
from the master switch or power window switch. The motor has a built–in
circuit breaker.

Parts Location

–

BODY ELECTRICAL SYSTEM

Power Window Control System

BE–147

Wiring and Connector Diagrams

BE–148

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BODY ELECTRICAL SYSTEM

Power Window Control System