Lexus RX300 (MCU15). Service manual — part 115

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BODY ELECTRICAL

TROUBLESHOOTING

BE–7

LEXUS RX300 (RM785E)

COMBINATION METER

Symptom

Suspect Area

See page

SRS warning light does not light up.

1. HEATER Fuse (Instrument Panel J/B)

2. Bulb

3. Meter Circuit Plate

4. Wire Harness

5. Airbag Sensor Assembly

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–

BE–62

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DI–434

Hi–beam indicator light does not light up.

1. Bulb

2. Meter Circuit Plate

3. Wire Harness

4. Headlight System

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BE–62

–

BE–29

Turn indicator light does not light up.

1. Bulb

2. Meter Circuit Plate

3. Wire Harness

4. Turn Signal and Hazard Warning System

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BE–62

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BE–43

ABS warning light does not light up.

1. GAUGE Fuse (Instrument Panel J/B)

2. Bulb

3. Meter Circuit Plate

4. Wire Harness

5. Skid Control ECU

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–

BE–62

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DI–203

TRAC warning light does not light up.

1. GAUGE Fuse

2. Bulb

3. Meter Circuit Plate

4. Wire Harness

5. Skid Control ECU

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–

BE–62

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DI–203

Malfunction indicator light does not light up.

1. Bulb

2. Meter Circuit Plate

3. Wire Harness

4. ECM

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BE–62

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Fuel level warning light does not light up.

1. Bulb

2. Fuel level warning switch

3. Meter Circuit Plate

4. Wire Harness

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BE–68

BE–62

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DEFOGGER SYSTEM

Symptom

Suspect Area

See page

All defogger systems do not operate.

1. HEATER Fuse (Instrument Panel J/B)

2. Defogger Switch

3. Wire Harness

4. Body ECU

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BE–79

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Rear window defogger does not operate.

1. DR DEF Fuse

2. Defogger Wire

3. Wire Harness

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BE–79

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Mirror defogger does not operate.

1. FR DEF Fuse (Instrument Panel J/B)

2. Mirror Defogger

3. Wire Harness

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BE–79

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BE–8

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BODY ELECTRICAL

TROUBLESHOOTING

LEXUS RX300 (RM785E)

POWER WINDOW CONTROL 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 power windows do not operate.

(Power Door Lock System is normal.)

1. Power Window Master Switch

2. Wire Harness

BE–84

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Only the driver’s window does not operate.

1. Power Window Master Switch

2. Power WIndow Switch

3. Power Window Motor

4. Wire Harness

BE–84

BE–84

BE–84

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”Window lock function” does not operate.

1. Power Window Master Switch

BE–84

POWER DOOR LOCK CONTROL 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 doors cannot be locked or unlocked.

1. Door Lock Control Switch

2. Driver Door ECU

3. Front Passenger Door ECU

4. Multiplex Communication Circuit

5. Body ECU

6. Wire Harness

BE–97

DI–598

DI–620

DI–676

DI–564

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Only driver’s side door lock control does not operate.

1. Driver Door ECU

2. Driver’s Door Lock Motor

3. Wire Harness

DI–598

BE–97

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Other doors than the driver’s side door do not operate.

1. Driver Door ECU

2. Multiplex Communication Circuit

3. Body ECU

4. Wire Harness

5. Door Lock Motor

DI–598

DI–676

DI–564

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BE–97

Door key related function does not operate.

1. Door Key Lock and Unlock Switch

2. Wire Harness

BE–97

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Key confinement prevention function does not operate.

1. Key Unlock Warning Switch

2. Wire Harness

3. Body ECU

BE–26

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DI–564

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

All the doors double lock system does not operate.

1. ECU–B Fuse

2. Wire Harness

3. Double Lock Control Relay

4. Body ECU

BE–97

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BE–105

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Only one side double lock system does not operate (or abnormal).

1. Double Lock Motor

2. Double Lock Switch

3. Wire Harness

4. Double Lock Control Relay

BE–105

BE–105

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BE–105

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BODY ELECTRICAL

TROUBLESHOOTING

BE–9

LEXUS RX300 (RM785E)

THEFT DETERRENT 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

The system cannot be set.

1. Indicator Light

2. Key Unlock Warning Switch

3. Door Unlock Detection Switch

4. Engine Hood Courtesy Switch

5. Back Door Courtesy Switch

6. Wire Harness

7. Body ECU

8. Driver Door ECU

9. Multiplex Communication Circuit

10.Transmitter

BE–109

BE–26

BE–97

BE–109

BE–48

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DI–564

DI–598

DI–676

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The system cannot be canceled when the ignition switch is turned

to ACC with key.

1. Key Unlock Warning Switch

2. Ignition Switch

3. Body ECU

4. RADIO NO.2 Fuse (Instrument panel J/B)

5. Wire Harness

BE–26

BE–26

DI–564

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The system cannot be canceled when the luggage compartment

door is unlocked with key.

1. Back Door Courtesy Switch

2. Body ECU

3. Wire Harness

BE–48

DI–564

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The system does not operate when the engine hood is opened.

1. Engine Hood Courtesy Switch

2. Body ECU

3. Wire Harness

BE–109

DI–564

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The system does not operate when the door is opened or un-

locked without using a key or transmitter.

1. Door Courtesy Switch

2. Driver Door ECU

3. Front Passenger Door ECU

4. Body ECU

5. Multiplex Communication Circuit

6. Door Unlock Detection Switch

7. Wire Harness

8. Transmitter

BE–48

DI–598

DI–620

DI–564

DI–676

BE–97

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The system does not operate when the ignition switch is turned to

ACC without using a key or transmitter.

1. Ignition Switch

2. Key Unlock Warning Switch

3. Body ECU

4. Wire Harness

5. Transmitter

BE–26

BE–26

DI–564

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–

Some of the does not operate.

(Headlight does not light up)

1. Headlight System

2. Wire Harness

3. Body ECU

BE–29

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DI–564

Some of the system does not operate.

(Taillight does not light up)

1. Taillight System

2. Wire Harness

3. Body ECU

BE–29

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DI–564

Some of the system does not operate.

(Theft deterrent horn or horn does not sound)

1. Theft Deterrent Horn

2. Horn

3. Horn Relay

4. HORN Fuse (Engine Room J/B)

5. Wire Harness

6. Body ECU

BE–109

BE–192

BE–192

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–

DI–564

BE–10

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BODY ELECTRICAL

TROUBLESHOOTING

LEXUS RX300 (RM785E)

While the warning is given, the system cannot be canceled by

unlocking the door with key or transmitter.

1. Door Key Lock and Unlock Switch

2. Body ECU

3. Wire Harness

4. Driver Door ECU

5. Front Passenger Door ECU

6. Multiplex Communication Circuit

7. Transmitter

BE–97

DI–564

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DI–598

DI–620

DI–676

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While the warning is given, the system cannot be canceled by

turning the ignition switch to ON with key.

1. Ignition Switch

2. Key Unlock Warning Switch

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

4. GAUGE Fuse (Instrument Panel J/B)

5. Body ECU

6. Wire Harness

BE–26

BE–26

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–

DI–564

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The system operates for more then 60 seconds.

1. Body ECU

BE–26

WIRELESS DOOR LOCK CONTROL SYSTEM
This system uses the multiplex communication system, so check diagnosis system of the multiplex commu-
nication system before you proceed with troubleshooting.
HINT:

S

Troubleshooting of the wireless door lock control system is based on the premise that the door lock
control system is operating normally. Accordingly, before troubleshooting the wireless door lock control
system, first make certain that the door lock control system is operating normally.

S

If the trouble still reappears even though there are no abnormalities in any of the other circuits, then
check and replace the Wireless Door Lock Control Receiver as the last step.

Symptom

Suspect Area

See page

All functions of wireless door lock control system do not operate.

1. Wireless Door Lock Control Receiver

2. Wire Harness

BE–116

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Wireless door lock operates, but the buzzer does not sound.

1. Wireless Door Lock Buzzer

2. Wireless Door Lock Control Receiver

3. Wire Harness

BE–116

BE–116

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POWER SEAT CONTROL SYSTEM

Symptom

Suspect Area

See page

Power seat does not operate.

(Door lock does not operate.)

1. Wire Harness

2. Power Seat Switch (D)

3. Power Seat Switch (P)

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BE–126

BE–126

Power seat does not operate.

(Door lock is normal.)

1. Wire Harness

2. Power Seat Switch (D)

3. Power Seat Switch (P)

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BE–126

BE–126

Driver’s seat does not operate.

1. Power Seat Switch (D)

2. Wire Harness

BE–126

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Passenger’s seat does not operate.

1. Power Seat Switch (P)

2. Wire Harness

BE–126

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”Slide operation” does not operate.

1. Power Seat Switch (D)

2. Power Seat Switch (P)

3. Wire Harness

4. Slide Motor (D, P)

BE–126

BE–126

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BE–126

”Front Vertical Operation” does not operate.

1. Power Seat Switch (D)

2. Power Seat Switch (P)

3. Wire Harness

4. Front Vertical Motor (D, P)

BE–126

BE–126

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BE–126

”Rear Vertical Operation” does not operate.

1. Power Seat Switch (D)

2. Wire Harness

3. Rear Vertical Motor (D, P)

BE–126

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BE–126