Lexus LS400 (2000 year). Manual - part 48

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BODY ELECTRICAL

TROUBLESHOOTING

BE–7

1870

HEADLIGHT BEAM LEVEL CONTROL SYSTEM

Symptom

Suspect Area

See page

Beam axis is not controlled. (It is not initialized.)

Headlight Beam Level Control System does not operate.

1. PWR–IG Fuse (Engine Room J/B)

2. Headlight Beam Level Control Actuator

3. Headlight Beam Level Control ECU

4. Wire Harness Side

BE–52

BE–52

Beam axis is not controlled. (It is initialized.)

Headlight Beam Level Control System does not operate.

1. Headlight Beam Level Control ECU 

2. Power Source Circuit

3. Height Control Sensor

4. Suspension ECU

5. Headlight Beam Level Control ECU

6. Wire Harness Side

BE–52

BE–19

DI–251

IN–32

BE–52

Controlled angle of head light is nnusual. (The angle is controlled.)

1. Height Control Sensor

2. Suspension ECU

3. Headlights

4. Wire Harness Side

DI–251

IN–32

Beam axis position is not stable during driving.

1. ABS System

2. Headlights

3. Wire Harness Side

FOG LIGHT SYSTEM

Symptom

Suspect Area

See page

Fog light does not light up with light control SW HEAD

(Headlight is normal.)

1. FOG Fuse (Instrument Panel J/B)

2. Fog Light Relay (Instrument Panel J/B)

3. Fog Light Switch

4. Wire Harness

BE–56

BE–38

Fog light does not light up with light control SW HEAD

(Headlight does not light).

1. 

*1

 Other Parts

2. Wire Harness

Only one light does not light up.

1. Bulb

2. Wire Harness

*1: Inspect Headlight System
TURN SIGNAL AND HAZARD WARNING SYSTEM

Symptom

Suspect Area

See page

”Hazard” and ”Turn” do not light up.

1. Hazard Warning Switch

2. Turn Signal Switch

3. Turn Signal Flasher

4. Wire Harness

BE–59

BE–38

BE–59

The flashing frequency is abnormal.

1. Bulb

2. Turn Signal Switch

3. Wire Harness

BE–38

Hazard warning light does not light up.

(Turn is normal)

1. HAZ Fuse (Engine Room J/B)

2. Wire Harness

Hazard warning light does not light up in one direction.

1. Hazard Warning Switch

2. Wire Harness

BE–59

*

1

 Turn signal does not light up.

1. Ignition Switch

2. TURN Fuse (Instrument Panel J/B)

3. Turn Signal Switch

4. Wire Harness

BE–33

BE–38

*

2

 Turn signal does not light up.

1. TURN Fuse (Instrument Panel J/B)

2. Turn Signal Switch

3. Wire Harness

BE–38

BE–8

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BODY ELECTRICAL

TROUBLESHOOTING

1871

Turn signal does not light up in one direction.

1. Turn Signal Switch

2. Wire Harness

BE–38

Only one bulb does not light up.

1. Bulb

2. Wire Harness

*

1

: Combination Meter, Wiper and Washer do not operate.

*

2

: Combination Meter, Wiper and Washer are normal.

ILLUMINATION LIGHT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.

Symptom

Suspect Area

See page

Illumination light do not light.

(Taillight is normal)

 1. PANEL Fuse (Instrument Panel J/B)

2. Rheostat Light Control

3. Wire Harness

BE–62

Illumination light do not light.

(Taillight does not light)

1. Taillight Control Relay (Instrument Panel J/B)

2. Taillight System

3. Rheostat Light Control

4. Wire Harness

5. PANEL Fuse (Instrument Panel J/B)

BE–38

BE–38

BE–62

Only one light does not light.

1. Bulb

2. Wire Harness

INTERIOR LIGHT SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.

Symptom

Suspect Area

See page

All the lights do not come ON.

1. DOME Fuse (Engine Room J/B)

2. DOME Fuse (Engine Room J/B)

3. Body ECU

DI–661

The light does not come ON when the driver’s door is opened.

1. Driver’s Door Courtesy Switch

2. Driver Door ECU

3. Multiplex Communication Circuit

4. Body ECU

5. Wire Harness

BE–70

DI–727

DI–838

DI–661

The light does not come ON when the passenger’s door is

opened.

1. Passenger’s Door Courtesy Switch

2. Front Passenger Door ECU

3. Multiplex Communication Circuit

4. Body ECU

5. Wire Harness

BE–70

DI–760

DI–838

DI–661

The light does not come on when the rear–right door is opened.

1. Rear–Right Door Courtesy Switch

2. Body ECU

3. Wire Harness

BE–70

DI–661

The light does not come on when the rear–left door is opened.

1. Rear–Left Door Courtesy Switch

2. Body ECU

3. Wire Harness

BE–70

DI–661

Only one of the bulbs comes ON.

1. Bulb

The illumination does not fade out when all the doors are closed.

1. Courtesy Switch

2. Driver Door ECU

3. Front Passenger Door ECU

4. Multiplex Communication Circuit

5. Body ECU

6. Wire Harness

BE–70

DI–727

DI–760

DI–838

DI–661

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BODY ELECTRICAL

TROUBLESHOOTING

BE–9

1872

The illumination does not fade out immediately when the ignition

switch is turned to ACC or ON within 15 seconds after all the

doors are closed.

1. Ignition Switch

2. RADIO NO.2 Fuse (Instrument Panel J/B)

3. GAUGE Fuse (Instrument Panel J/B)

4. Body ECU

5. Wire Harness

BE–33

DI–661

The illumination does not fade out immediately when all the doors

are locked within 15 seconds after they are closed.

1. Door Unlock Detection Switch

2. Driver Door ECU

3. Front Passenger Door ECU

4. Multiplex Communication Circuit

5. Body ECU

6. Wire Harness

BE–139

DI–727

DI–760

DI–838

DI–661

Interior light does not light up.

(in front personal light)

1. Bulb

2. Front Personal Light

3. Wire Harness

BE–70

Front personal light does not light up.

1. Bulb

2. Front Personal Light

3. Wire Harness

BE–70

Rear personal light does not light up.

1. Bulb

2. Rear Personal Light

3. Wire Harness

BE–70

Vanity light does not light up.

1. Bulb

2. Vanity Light

3. Wire Harness

BE–70

Luggage compartment light does not light up.

1. Bulb

2. Luggage Compartment Door Courtesy Switch

3. Wire Harness

BE–70

Courtesy light does not light up.

1. Bulb

2. Door Courtesy Switch

3. Wire Harness

BE–70

STOP LIGHT SYSTEM

Symptom

Suspect Area

See page

Stop light does not light up.

1. STOP Fuse (Instrument Panel J/B)

2. Stop Light Switch

3. Light Failure Sensor

4. Wire Harness

BE–76

BE–76

Stop light always lights up.

1. Stop Light Switch

2. Wire Harness

BE–76

Only one light always lights up.

1. Wire Harness

Only one light does not light up.

1. Bulb

2. Wire Harness

HEADLIGHT CLEANER SYSTEM

Symptom

Suspect Area

See page

”Headlight Cleaner System” does not operate

(Using light control switch)

1. Light control switch

2. Wire Harness

BE–38

”Headlight Cleaner System” does not operate

(When operating ”Running Light System”)

1. Daytime Running Light Relay (Main)

2. Wire Harness

BE–38

BE–10

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BODY ELECTRICAL

TROUBLESHOOTING

1873

”Headlight Cleaner System” does not operate

(All)

1. AM1 H–Fuse

2. WIPER Fuse

3. Ignition Switch

4. Headlight Cleaner Switch

5. Headlight Cleaner Relay

6. Headlight Cleaner Motor

7. Headlight Cleaner Nozzle and Hose

8. Wire Harness

BE–33

BE–79

BE–79

BE–79

Washer fluid does not spray

1. Headlight Cleaner Nozzle and Hose

WIPER AND WASHER SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.

Symptom

Suspect Area

See page

Wiper and washers do not operate.

1. WIPER Fuse (Instrument Panel J/B)

2. Wiper Switch

3. Wiper Motor

4. Body ECU

5. Wire Harness

BE–82

BE–82

DI–661

Wipers do not operate in LO, HI or MIST.

1. Wiper Switch

2. Wiper Motor

3. Wire Harness

BE–82

BE–82

Wipers do not operate in INT.

1. Wiper Switch

2. Wiper Motor

3. Body ECU

4. Wire Harness

BE–82

BE–82

DI–661

Washer motor does not operate.

1. Washer Switch

2. Washer Motor

3. Wire Harness

BE–82

BE–82

Wipers do not operate when washer switch in ON.

1. Washer Motor

2. Body ECU

3. Wire Harness

BE–82

DI–661

Washer fluid does not operate.

1. Washer Hose and Nozzle

 When wiper switch is at HI position, the wiper blade is in

contact with the body.

 When the wiper switch is OFF, the wiper blade does not

retract or the retract position wrong.

1. Wiper Motor *

2. Wire harness *

3. Body ECU

BE–82

DI–661

*: Inspect wiper arm and blade set position.
COMBINATION METER

Symptom

Suspect Area

See page

SRS warning light does not light up.

1. MPX–B Fuse

2. Bulb

3. Meter Circuit Plate

4. Wire Harness

5. Airbag Sensor Assembly

BE–86

DI–574

Hi–beam indicator light does not light up.

1. Bulb

2. Meter Circuit Plate

3. Wire Harness

4. Headlight System

BE–86

BE–36

Turn indicator light does not light up.

1. Bulb

2. Meter Circuit Plate

3. Wire Harness

4. Turn Signal and Hazard Warning System

BE–86

BE–58