Lexus RX300 (MCU15). Service manual - part 113

BODY ELECTRICAL

BODY ELECTRICAL SYSTEM

BE–1

. . . . . . . . . . . . . 

TROUBLESHOOTING

BE–2

. . . . . . . . . . . . . . . . . . . . 

POWER SOURCE

BE–13

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IGNITION SWITCH AND KEY UNLOCK 

WARNING SWITCH

BE–25

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HEADLIGHT AND TAILLIGHT SYSTEM

BE–28

. . . . 

HEADLIGHT BEAM LEVEL CONTROL

 SYSTEM

BE–38

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FOG LIGHT SYSTEM

BE–40

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TURN SIGNAL AND HAZARD 

WARNING SYSTEM

BE–43

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INTERIOR LIGHT SYSTEM

BE–47

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STOP LIGHT SYSTEM

BE–52

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WIPER AND WASHER SYSTEM

BE–55

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COMBINATION METER

BE–61

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DEFOGGER SYSTEM

BE–78

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POWER WINDOW CONTROL SYSTEM

BE–81

. . . . 

POWER DOOR LOCK CONTROL

 SYSTEM

BE–96

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

DOUBLE LOCKING SYSTEM

BE–104

. . . . . . . . . . . . . 

THEFT DETERRENT SYSTEM

BE–108

. . . . . . . . . . . . 

WIRELESS DOOR LOCK CONTROL

 SYSTEM

BE–110

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POWER SEAT CONTROL SYSTEM

BE–125

. . . . . . . . 

POWER MIRROR CONTROL SYSTEM

BE–133

. . . . . 

ELECTRO CHROMIC MIRROR SYSTEM

BE–136

. . . 

SEAT HEATER SYSTEM

BE–139

. . . . . . . . . . . . . . . . . . 

AUDIO SYSTEM (Europe)

BE–142

. . . . . . . . . . . . . . . . . 

AUDIO SYSTEM (Except Europe)

BE–149

. . . . . . . . . . 

ANTENNA

BE–181

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

MULTI DISPLAY

BE–188

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ENGINE IMMOBILISER SYSTEM

BE–189

. . . . . . . . . . 

HORN SYSTEM

BE–191

. . . . . . . . . . . . . . . . . . . . . . . . . 

BE0DC–06

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BODY ELECTRICAL

BODY ELECTRICAL SYSTEM

BE–1

LEXUS RX300   (RM785E)

BODY ELECTRICAL SYSTEM

PRECAUTION

Take care to observe the following precautions when performing inspections or removal and replacement
of body electrical related parts.

1.

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

The LEXUS RX300 is equipped with an SRS (Supplemental Restraint System) such as the driver airbag and
front passenger airbag. failure to carry out service operation in the correct sequence could cause the SRS
to unexpectedly deployed during servicing, possibly leading to a serious accident. Before servicing (includ-
ing removal or installation of parts, inspection or replacement), be sure to read the precautionary codices
in the RS section.

2.

COMBINATION METER SYSTEM

The cold cathode tube connectors (Connectors ”N”, ”P” and ”Q”) in the combination meter are charged with
high voltage AC current when power is supplied, so do not touch them when they are charged.

3.

AUDIO SYSTEM

If the battery negative (–) terminal is disconnected, the preset AM, FM 1 and FM 2 stations stored in memory
are erased, so be sure to not the stations and reset them after the battery terminal is reconnected.

4.

MOBILE COMMUNICATION SYSTEM

If the vehicle is equipped with a mobile communication system, refer to precautions in the IN section.

BE1AT–02

BE–2

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BODY ELECTRICAL

TROUBLESHOOTING

LEXUS RX300   (RM785E)

TROUBLESHOOTING

PROBLEM SYMPTOMS TABLE

The table below will be useful for you in troubleshooting these electrical problems. The most likely causes
of the malfunction are shown in the order of their probability. Inspect each part in the order shown, and re-
place the part when it is found to be faulty.
IGNITION SWITCH:
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

Ignition switch is not set to each position.

5. Ignition switch

6. Power source circuit

BE–26

BE–18

KEY UNLOCK WARNING SWITCH:
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

Key unlock warning system does not operate.

(The buzzer does not sound when the driver’s door is opened with

the ignition OFF and key inserted)

1. Key Unlock Warning Switch

2. Door Courtesy Switch

3. Driver Door ECU

4. Multiplex Communication Circuit

5. Body ECU

6. Wire Harness

BE–26

BE–48

DI–598

DI–676

DI–564

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Key unlock warning system does not operate.

(The buzzer sounds when the ignition key is ACC or ON)

1. Ignition Switch

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

3. GAUGE Fuse (Instrument Panel J/B)

4. Wire Harness

BE–26

–

–

–

HEADLIGHT AND TAILLIGHT SYSTEM:
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
HINT:
To inspect the bulb and light control ECU, replace them with the ones working normally and judge whether
they work normally or not.

Symptom

Suspect Area

See page

Only one headlight comes on.

1. H–LP L LWR Fuse (Engine Room J/B)

2. H–LP R LWR Fuse (Engine Room J/B)

3. Headlight Bulb

4. Wire Harness

–

–

–

–

”LO–Beam” does not light (All).

1. Headlight Dimmer Switch

2. Wire Harness

BE–31

–

”LO–Beam” does not light (One side).

1. Headlight Bulb

2. Wire Harness

–

–

”HI–Beam” does not light (All).

1. Headlight Dimmer Switch

2. Wire Harness

BE–31

–

”HI–Beam” does not light (One side).

1. Headlight Bulb

2. Wire Harness

–

–

”Flash” does not light.

1. Headlight Dimmer Switch

2. Wire Harness

BE–31

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