Lexus RX300 (MCU15). Service manual - part 340

I12716

BCTY

13

B7

5

IA2

Battery

1

BC2

5

W–R

W–R

A

2I

1

Junction
Connector

R19
Rear Interior Light

DOOR

D4
DIODE

R–B

W–R

W–R

2

2 1

R

1

1

BC2

A

J3

C

J4

R

2A

3

R

DOME

Short Pin

Engine Room J/B

Junction
Connector

J14

W–R

ON

Body ECU

BN

2

B9
Back Door
Courtesy Switch

W

1

3

1

W–B

W

F11
FL Block

DI–592

–

DIAGNOSTICS

BODY CONTROL SYSTEM

LEXUS RX300   (RM785E)

Rear interior light and back door courtesy switch circuit

CIRCUIT DESCRIPTION

The back door courtesy switch goes on when back door is opened and goes off when back door is closed.

WIRING DIAGRAM

DI1OZ–07

–

DIAGNOSTICS

BODY CONTROL SYSTEM

DI–593

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

HINT:
In case of using the hand–held tester, start the inspection from step 1 and incase of not using the hand–held
tester, start from step 2.

1

Check back door courtesy switch using hand–held tester.

PREPARATION:
Connect the hand–held tester to the DLC 3.
CHECK:
Check the back door courtesy switch using DATA LIST.

OK

Proceed to next circuit inspection shown on
problem symptoms table (See page DI–570).

NG

2

Check back door courtesy switch (See page BE–109).

NG

Replace the back door courtesy switch.

OK

3

Check wireharness and connector between back door courtesy switch and Body
ECU.

NG

Repair or replace wireharness or connector.

OK

Proceed to next circuit inspection shown on
problem symptoms table (See page 
DI–570).

I08133

S10
Stop Light Switch

5E

STOP

B7

G–O

18

Body ECU

5E

1A

12

11

1

STPI

1

Instrument Panel J/B

J/B No.5

G–W

G–B

1E

ALT
FUSE

1

2

DI–594

–

DIAGNOSTICS

BODY CONTROL SYSTEM

LEXUS RX300   (RM785E)

Stop light switch circuit

CIRCUIT DESCRIPTION

The Body ECU is detecting the condition of the stop light switch.

WIRING DIAGRAM

DI1P4–12

–

DIAGNOSTICS

BODY CONTROL SYSTEM

DI–595

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

HINT:
In case of using the hand–held tester, start the inspection from step 1 and in case of not using the hand–held
tester, start from step 2.

1

Check stop light switch using hand–held tester.

PREPARATION:
Connect the hand–held tester to the DLC 3.
CHECK:
Check the stop light switch using DATA LIST.

OK

Proceed to next circuit inspection shown on
problem symptoms table (See page DI–570).

NG

2

Check stop light switch (See page BE–53).

NG

Replace the stop light switch.

OK

3

Check wireharness and connector between stop light switch and Body ECU, bat-
tery and stop light switch.

NG

Repair or replace wireharness or connector.

OK

Proceed to next circuit inspection shown on
problem symptoms table
(See page DI–570).