Lexus LS400 (2000 year). Manual - part 51

BE0BA–01

I03228

Driver Door ECU

Body ECU

Instrument Panel Junction Block

 GAUGE Fuse

 RADIO No.2 Fuse

Ignition Switch and Key Unlock
Warning Switch

Door Lock Assembly

 Door Courtesy Switch

Door Lock Assembly

 Door Courtesy Switch

BE–32

–

BODY ELECTRICAL

IGNITION SWITCH AND KEY UNLOCK WARNING 
SWITCH

1895

IGNITION SWITCH AND KEY UNLOCK WARNING SWITCH

LOCATION

BE0BB–01

N11771

1

2

3

4
8 7 6 5

N11771

1

2

3

4
8

7 6 5

Z14750

OFF

ON

–

BODY ELECTRICAL

IGNITION SWITCH AND KEY UNLOCK WARNING 
SWITCH

BE–33

1896

INSPECTION

1.

INSPECT IGNITION SWITCH CONTINUITY

Switch position

Tester connection

Specified condition

LOCK

–

No continuity

ACC

2 – 3

Continuity

ON

2 – 3 – 4

6 – 7

Continuity

START

1 – 2 – 4

6 – 7 – 8

Continuity

If continuity is not as specified, replace the switch.

2.

INSPECT IGNITION SWITCH CIRCUIT

Connect the switch connector and inspect the connector on the
wire harness side from the back side, as shown.
If circuit is not as specified, inspect the switch and circuits con-
nected to other parts.

Tester connection

Condition

Specified condition

1– Ground

Ignition switch turned to START

Battery positive voltage

2 – Ground

Constant

Battery positive voltage

3 – Ground

Ignition switch turned to ACC or ON

Battery positive voltage

4 – Ground

Ignition switch turned to ON

Battery positive voltage

6 – Ground

Ignition switch turned to ON

Battery positive voltage

7 – Ground

Constant

Battery positive voltage

8– Ground

Ignition switch turned to START

Battery positive voltage

3.

INSPECT KEY UNLOCK WARNING SWITCH CONTI-
NUITY

Switch position

Tester connection

Specified condition

OFF

(Ignition key removed)

 –

No continuity

ON

(Ignition key set)

1 – 2

Continuity

If continuity is not as specified, replace the switch.

Z14751

BE–34

–

BODY ELECTRICAL

IGNITION SWITCH AND KEY UNLOCK WARNING 
SWITCH

1897

4.

INSPECT KEY UNLOCK WARNING SWITCH CIRCUIT

Connect the switch connector and inspect the connector on the
wire harness side from the back side, as shown.

Tester connection

Condition

Specified condition

2 – Ground

Ignition key removed

No continuity

2 – Ground

Ignition key set

Continuity

1 – Ground

Constant

Continuity

If circuit is not as specified, inspect the switch or wire harness.

BE0BC–03

I09285

Engine Room Junction Block

 H–LP R LWR Fuse

 H–LP L LWR Fuse

 H–LP R UPR Fuse

 H–LP L UPR Fuse

 DRL Fuse

 ECU–B Fuse

 H–LP Relay

 DIM Relay (USA)

 Daytime Running Light No.2 Relay

Daytime Running Light
No.3 and No.4 Relay

Automatic Light
Control Sensor

Body ECU

Daytime Running Light
Main Relay

Driver Door ECU

Door Lock Assembly

 Door Courtesy Switch

Rear Light Assembly

Rear Combination
Light

Combination Switch

 Light Control Switch

 Dimmer Switch

Instrument Panel Junction Block

 TAIL Fuse

 GAUGE Fuse

 TAIL Relay

Headlight

–

BODY ELECTRICAL

HEADLIGHT AND TAILLIGHT SYSTEM

BE–35

1898

HEADLIGHT AND TAILLIGHT SYSTEM

LOCATION