Lexus LS400 (2000 year). Manual — part 56

BE0BI–01

I03440

6

3

5

2

1

4

I03274

Wire Harness Side

BE–52

–

BODY ELECTRICAL

HEADLIGHT BEAM LEVEL CONTROL SYSTEM

1915

INSPECTION

1.

INSPECT HEADLIGHT BEAM LEVEL CONTROL AC-
TUATOR RESISTANCE

(a)

Check that continuity exists between terminal 2 and 5.

(b)

Check that resistance exists between terminal, as shown
in the chart.

Terminal

Resistance (

Ω

)

2 – 1

26 – 30

2 – 3

26 – 30

2 – 4

26 – 30

2 – 6

26 – 30

5 – 1

26 – 30

5 – 3

26 – 30

5 – 4

26 – 30

5 – 6

26 – 30

If resistance value is not as specified, replace the actuator.

2.

INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU
CIRCUIT
Connector disconnected:

Disconnect the connector from the ECU and inspect the con-
nector on the wire harness side, as shown.

Tester connection

Condition

Specified condition

1 – 4

Ignition switch OFF

26 – 30

Ω

1 – 5

Ignition switch OFF

26 – 30

Ω

1 – 6

Ignition switch OFF

26 – 30

Ω

1 – 7

Ignition switch OFF

26 – 30

Ω

1 – 17

Ignition switch OFF

26 – 30

Ω

1 – 18

Ignition switch OFF

26 – 30

Ω

1 – 19

Ignition switch OFF

26 – 30

Ω

1 – 20

Ignition switch OFF

26 – 30

Ω

10 – 25

Ignition switch OFF

Continuity

21 – 25

Ignition switch OFF

Continuity

24 – 25

Ignition switch OFF

Continuity

13 – Ground

Ignition switch OFF

Continuity

26 – Ground

Ignition switch OFF

Continuity

If circuit is not as specified, perform the inspection on the follow-
ing page.

I03275

From Back Side

–

BODY ELECTRICAL

HEADLIGHT BEAM LEVEL CONTROL SYSTEM

BE–53

1916

3.

INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU
CIRCUIT
Connector connected:

Connect the connector from the ECU and inspect the connector
on the back side, as shown in the chart.

Tester connection

Condition

Specified condition

1 – 13

Ignition switch ON

Battery positive voltage

4 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

5 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

6 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

7 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

10 – 25

Ignition switch ON

Approx. 2.5 V

12 – 13

Ignition switch ON

No continuity

26 – Body ground

Ignition switch OFF

Continuity (w/ Electrical modulated air suspen-

sion)

13 – 15

Ignition switch ON and light control switch HEAD

Below 1.5 V

17 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

18 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

19 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

20 – 13, 26

Ignition switch ON, when keep and bounce the

vehicle

*1 Pulse generation

21 – 25

Ignition switch ON

Approx. 2.5 V

13 – 22

*2 Pulse generation

13 – 23

*2 Pulse generation

24 – 25

Ignition switch ON

5 V

13 – 25

Ignition switch OFF

Continuity

13 – Body ground

Ignition switch OFF

Continuity

If the circuit is not as specified, replace the ECU.

I03276

10 m sec./ Division

Motor operating

5V
/ Division

GND

*1 Pulse generation

*2 Pulse generation

10 m sec./ Division

Motor operating

5V
/ Division

GND

BE–54

–

BODY ELECTRICAL

HEADLIGHT BEAM LEVEL CONTROL SYSTEM

1917

Reference INSPECTION USING OSCILLOSCOPE
HINT:
The correct waveform is as shown in the illustration.

BE0BJ–01

I03229

Headlight Assembly

Fog Light

Combination Switch

Fog Light Switch

Light Control Switch

Instrument Panel
Junction Block

FOG Fuse

Fog Light Relay

–

BODY ELECTRICAL

FOG LIGHT SYSTEM

BE–55

1918

FOG LIGHT SYSTEM

LOCATION