Section 327 (Headlight Beam Level Control System): Inspection
WARNING: This page is about a different car, the 2003 Lexus GS 430 and 2003 Lexus GS 300. 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 terminals 2 and 5.
- Check that resistance exists between terminals, as shown in HEADLIGHT BEAM LEVEL CONTROL ACTUATOR RESISTANCE
.HEADLIGHT BEAM LEVEL CONTROL ACTUATOR 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.
- INSPECT FRONT HEIGHT CONTROL SENSOR
- Connect 3 dry batteries of 1.5 V in series.
- Connect terminal 1 to the batteries' positive (+) terminal, and terminal 4 to the batteries' negative (-) terminal, then apply voltage about 4.5 V between terminals 1 and 4.
- Measure the voltage between terminals 2 and 4, when the height control sensor link is slowly moved up and down.FRONT HEIGHT CONTROL SENSOR VOLTAGE
Sensor Link Position Voltage Max. Hl Approx. 4.05 V N Approx, 2.25 V Min. LO Approx, 0.45 V If voltage is not as specified, replace the height control sensor.
- INSPECT REAR HEIGHT CONTROL SENSOR
- Connect 3 dry batteries of 1.5 V in series.
- Connect terminal 3 to the batteries' positive (+) terminal, and terminal 1 to the batteries' negative (-) terminal, then apply voltage about 4.5 V between terminals 1 and 3.
- Measure the voltage between terminals 1 and 2, when the height control sensor link is slowly moved up and down.REAR HEIGHT CONTROL SENSOR VOLTAGE
Sensor Link Position Voltage Max. Hl Approx. 4.05 V N Approx. 2.25 V Min. LO Approx. 0.45 V If voltage is not as specified, replace the height control sensor.
- 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 in Fig 4.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HEADLIGHT BEAM LEVEL CONTROL ECU CONNECTOR SPECIFIED CONDITIONTester connection Condition Specified condition A1 - A5 Ignition switch OFF 26 - 30 Ω A1 - A6 Ignition switch OFF 26 - 30 Ω A1 - A7 Ignition switch OFF 26 - 30 Ω A1 - A8 Ignition switch OFF 26 - 30 Ω A4 - B4 ignition switch ON and light control switch HEAD Below 1.5 V B1 - B3 Ignition switch OFF 3.5 - 6.5 Ω B5 - B7 Ignition switch OFF 3.5 - 6.5 Ω A4 - Ground Ignition switch OFF Continuity If circuit is not as specified, perform the inspection on the following pages.
- Connector connected: INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU CIRCUIT
Connect the connector from the ECU and inspect the connector, as shown in HEADLIGHT BEAM LEVEL CONTROL ECU CONNECTOR SPECIFIED CONDITION .
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HEADLIGHT BEAM LEVEL CONTROL ECU CONNECTOR SPECIFIED CONDITIONTester connection Condition Specified condition A1 - A4 Ignition switch ON Battery positive voltage A1 - A5 Ignition switch ON, when stopping and bouncing the vehicle. Pulse generation A1 - A6 Ignition switch ON, when stopping and bouncing the.vehicle. Pulse generation A1 - A7 Ignition switch ON, when stopping and bouncing the vehicle. Pulse generation A1 - A8 Ignition switch ON, when stopping and bouncing the vehicle. Pulse generation B2 - B3 Ignition switch ON Approx. 2.5 V B6 - B7 Ignition switch ON Approx. 2.5 V B1 -B3 B5 - B7 Ignition switch ON 5 V If the circuit is not as specified, replace the ECU.
Reference INSPECTION USING OSCILLOSCOPE
HINT:
The correct waveform is as shown in Fig 6 .