Lexus ES300 (1997 year). Manual - part 421

N21273

Integration Relay

Wireless Door Lock ECU

Theft Deterrent ECU

Instrument Panel J/B

J33

J38

J37

IF3

J11

I14

J10

IO2

IG

20

IE2

J/C

F

L–R

11

W8 LSWD

W–B

IV

J10

J11

L–R

L–R

Y

L–Y

Y

L–Y

L–Y

L–Y

IP1

L–Y

IE1

W–B

W–B

W–B

IO2

W–B

W–B

B

B

J/C

F

F

F

C

C

C

C

C

A

A

2

3

11

11

Front
RH

Rear
RH

Rear
LH

W–B

W–B

20

9

9

A

A

B

B

Door
Unlock
Detection
Switch

Door
Unlock
Detection
Switch

4

4

L–R

Y

W–B

Front
LH

W–B

I14

I14

9

7

5

IF

IL

IM

BN

BR1

BR1

BQ1

BR1

BQ1

7

3

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

DI–461

613

1997 LEXUS ES300   (RM511U)

 Door Unlock Detection Switch Circuit

CIRCUIT DESCRIPTION

The door unlock detection switch is built into the door lock motor assembly. The switch is OFF when the door
lock knob is in Lock Position, and is ON When the Knob is in Unlock position.
Furthermore, the door unlock detection switch circuit has terminal +B connected inside the theft deterrent
ECU, when the door unlock detection switch is OFF, batter positive voltage is applied to the terminal of the
door unlock detection switch circuit of the wireless door lock ECU.

WIRING DIAGRAM

DI0E0–01

N11388

N22140

I00640

Illumination shows
Front LH

LSWD(+)

DI–462

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

614

1997 LEXUS ES300   (RM511U)

INSPECTION PROCEDURE

1

Check voltage between terminals LSWD, LSWP and LSWR of wireless door lock
ECU connector and body ground.

PREPARATION:
Remove the wireless door lock ECU from No.1 instrument pan-
el brace.
CHECK:
Measure voltage between terminals LSWD, LSWP and LSWR
of wireless door lock ECU connector and body ground, when
the respective door lock knob involved is pushed to the lock
side.
OK:

Voltage 10 – 14 V

OK

Proceed to next circuit inspection shown on
matrix chart (See page 

DI–456

).

NG

Check and repair harness and connector between wireless door lock ECU and door unlock
detection switch.

N21272

Wireless Door Lock ECU

Theft Deterrent ECU

19

UL3

IO2

W–B

IE2

Instrument panel J/B

R–G

I14

UNLOCK

LOCK

Door Key
Lock and
Unlock
Switch

W–B

W–B

W–B

W–B

R–G

R–G

UNLOCK

LOCK

IO2

IE2

L

B

IF

IL

1

2

3

20

LH

RH

J/C

J38

A

1

2

3

B

B

R–G

L

A

A

L

3

3

20

B

B

W8

7

J7

B

R–G

Integration Relay

I14

20

W–B

1G

1V

W–B

B

B

7

3

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

DI–463

615

1997 LEXUS ES300   (RM511U)

 Door Key Lock and Unlock Switch Circuit (Unlock Side)

CIRCUIT DESCRIPTION

The key operated switch is built into the door key cylinder. When the key is turned to the lock side, the lock
terminal of the switch is grounded, and when the key is turned to the unlock side the unlock terminal is
grounded. 
Furthermore, the door key lock and unlock switch circuit has terminal +B connected inside the theft deterrent
ECU, when neither the lock or unlock terminal of the key lock and unlock switch are grounded, battery posi-
tive voltage is applied to the door key lock and unlock switch circuit of the wireless door lock ECU.
( Tr inside the ECU coming ON causes the wireless door lock ECU to output a signal to unlock all the doors.)

WIRING DIAGRAM

DI0E2–01

N22139

UL2(+)

DI–464

–

DIAGNOSTICS

WIRELESS DOOR LOCK CONTROL SYSTEM

616

1997 LEXUS ES300   (RM511U)

INSPECTION PROCEDURE

1

Check voltage between terminals UL2 of wireless door lock ECU connector and
body ground.

PREPARATION:
Remove the wireless door lock ECU from No.1 instrument pan-
el brace.
CHECK:
Measure voltage between terminal UL2 of wireless door lock
ECU connector and body ground.
OK:

Voltage: 10 – 14V

OK

Proceed to next circuit inspection shown on
matrix chart (See page 

DI–456

).

NG

Check and repair harness and connector between wireless door lock ECU and door key lock and
unlock switch.