Section 380 (Headlight Beam Level Control System): Inspection

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT HEADLIGHT BEAM LEVEL CONTROL ACTUATOR RESISTANCE

Check that continuity exists between terminal 2 and 5.

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

TERMINAL RESISTANCE

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.

Fig 1: Identifying Headlight Beam Level Control Actuator Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connector disconnected: INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU CIRCUIT

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

Fig 2: Identifying Headlight Beam Level Control ECU Terminals (Wire Harness Side)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CONNECTOR SPECIFIED CONDITION

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 in the following steps.

Connector connected: INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU CIRCUIT

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

Fig 3: Identifying Headlight Beam Level Control ECU Terminals (Connector Connected)

CONNECTOR SPECIFIED CONDITION

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	Pulse generation
5 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	Pulse generation
6 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	Pulse generation
7 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	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 suspension)
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	Pulse generation
18 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	Pulse generation
19 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	Pulse generation
20 - 13, 26	Ignition switch ON, when keep and bounce the vehicle	Pulse generation
21 - 25	Ignition switch ON	Approx. 2.5 V
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.