Headlights: Diagnosis Toyota Sequoia I

Inspect Automatic Light Control

AUTO ON

Scheme 14

1. Turn the ignition switch ON.
2. Turn the light control switch to AUTO.
3. Gradually cover the top of the sensor.
4. Check the accessory lights and the headlights should turn ON.

AUTO OFF

1. Gradually expose the sensor.
2. Check the headlights and the accessory lights should turn OFF.

Inspect Lights-Off Condition

1. Turn the ignition switch ON.
2. Lights auto ON, gradually cover the top of the sensor.
3. Check that the lights go off under the following conditions. Light control switch is OFF. The area surrounding the sensor gets bright. After the ignition switch is turned OFF and after 30 sec. from when open doors are all closed.

Inspect Lights-On Condition

1. Open the driver's door while the ignition switch is OFF.
2. Turn the light control switch to AUTO leaving the door open and cover the top of the sensor, make sure that the lights go on when the ignition switch is turned ON.

Scheme 15

1. Adjustment of the light control is performed by turning the sensitivity knob on the sensor.
2. This will be determined at what light condition the automatic control will take place. If response is too quick, turn the knob counterclockwise. If response is too slow, turn the knob clockwise.

Scheme 16

Scheme 17

Scheme 18

Scheme 19

1. Connector connected: NOTE: Connect the wire harness side connector to the sensor and inspect wire harness side connector from the back side, as shown. Ignition switch ON. Light control switch AUTO. Vehicle's surroundings are bright. If circuit is as specified, try replacing the sensor with a new one. If the circuit is not as specified, inspect the circuit connected to other parts.
2. Connector disconnected: Disconnect the connector from the sensor and inspect the connector on the wire harness side (Scheme 19) If circuit is as specified, perform the inspection on the following page. If the circuit is not as specified, inspect the circuit connected to other parts.

Scheme 20

Scheme 21

If continuity is not as specified, replace the resistor.

Scheme 22

Scheme 23

1. Adjust Headlight Aiming
2. Adjust headlight aim only: Place the vehicle in the following conditions. The area around the headlight is not deformed. The vehicle is parked on a level surface. Tire inflation pressure is the specified value. A driver is in the driver's seat and the vehicle is in a state ready for driving (with a tank full). The vehicle has been bounced several times. Check the headlight aiming. Prepare a thick white paper. Stand the paper perpendicular to the ground at the position 9.84 ft away from the headlights. Ensure that the center line of the vehicle and the paper face forms a 90-degree angle as shown in the illustration. NOTE: Steps 4 - 7 are called out in (Scheme 23). Draw a horizontal line (H line) on the paper, showing where the headlights should strike. Draw a vertical line (V line) to where the center line of the vehicle is to be. Draw 2 vertical lines (by connecting the low and high beam center marks) to where the both headlights should strike (V RH and V LH lines). NOTE: The H RH and H LH line is 0.4° below the horizontal line (H line) of the light axis. As shown in the illustration, adjust each aim of the RH and LH lights. (Scheme 23) Draw a horizontal line (by connecting the both low beam center marks) to where the headlights should strike (H RH and H LH lines). Start the engine. Turn the headlights ON. Check that the headlights properly strike the position (Scheme 23) If not, adjust the lights in the vertical or horizontal direction. When adjusting it in the vertical direction, using adjusting bolt, adjust the headlight aim to within the specified range.