Lexus RX300 (MCU15). Service manual - part 344

I19265

Driver Door ECU

LSWE

A–

A+

LSW

24

2

16

L–R

6

19

KL

KUL

13

L–Y

GR–R

GR

P

P–L

4 (*1)

D7 (*1)
D8 (*2)
Door Lock Motor LH

Door Lock Motor

Door Unlock
Detection Switch

Door Key Lock and 
Unlock Switch

D12

D12

D12

D12

D12

D12

2 (*2)

3 (*1)

1 (*2)

7 (*1)

6 (*2)

8 (*1)

5 (*2)

2 (*1)

3 (*2)

1 (*1)

4 (*2)

*1: LHD
*2: RHD

DI–608

–

DIAGNOSTICS

DRIVER DOOR CONTROL SYSTEM

LEXUS RX300   (RM785E)

Door unlock detection switch circuit

CIRCUIT DESCRIPTION

The door unlock detection switch is built in the door lock motor assembly. This switch is ON when the door
lock knob is in the unlock position and OFF when the lock knob is in the lock position. The ECU detects the
door lock knob conditions is this circuit. It is used as one of the operating conditions for the key confinement
prevention function.

WIRING DIAGRAM

DI2BP–10

–

DIAGNOSTICS

DRIVER DOOR CONTROL SYSTEM

DI–609

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 door unlock detection switch using hand–held tester.

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

OK

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

NG

2

Check door unlock detection switch (See page BE–97).

NG

Replace the door lock motor.

OK

3

Check wireharness and connector between door unlock detection switch and
driver door ECU.

NG

Repair or replace wireharness or connector.

OK

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

I19265

Driver Door ECU

LSWE

A–

A+

LSW

24

2

16

L–R

6

19

KL

KUL

13

L–Y

GR–R

GR

P

P–L

4 (*1)

D7 (*1)
D8 (*2)
Door Lock Motor LH

Door Lock Motor

Door Unlock
Detection Switch

Door Key Lock and 
Unlock Switch

D12

D12

D12

D12

D12

D12

2 (*2)

3 (*1)

1 (*2)

7 (*1)

6 (*2)

8 (*1)

5 (*2)

2 (*1)

3 (*2)

1 (*1)

4 (*2)

*1: LHD
*2: RHD

DI–610

–

DIAGNOSTICS

DRIVER DOOR CONTROL SYSTEM

LEXUS RX300   (RM785E)

Door key lock and unlock switch circuit

CIRCUIT DESCRIPTION

The door key lock and unlock switch is built in the door key cylinder. When the key is turned to the lock side,
terminal 3 of the switch is grounded and when the key is turned to the unlock side, terminal 2 of the switch
is grounded.
Door key lock and unlock switch can be checked using DTC check. (Refer to DI–708)

WIRING DIAGRAM

DI2BQ–10

–

DIAGNOSTICS

DRIVER DOOR CONTROL SYSTEM

DI–611

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

Check the door key lock and unlock switch using DTC check 
(See page DI–708).

OK

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

NG

2

Check the door key lock and unlock switch (See page BE–97).

NG

Replace the door key lock and unlock switch.

NG

3

Check wireharness and connector between door key lock and unlock switch and
driver door ECU.

NG

Repair or replace wireharness or connector.

OK

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