HEADLAMP LEVELING MOTOR
DESCRIPTION
The headlamp leveling motor (1) is located on the rear inboard side of each headlamp unit (5) on vehicles equipped with the headlamp leveling system, which is available only in certain markets where required. The motor is encased within a molded plastic housing and is secured by an integral wedge-type mounting boss to a keyed flange on the back of the headlamp unit housing. A rubber seal around the circumference of the mounting boss seals the motor to the headlamp.
The outside of the motor housing features an integral molded connector on its rearward surface, a hex-headed adjusting screw extends from the top of the housing, and a plastic pushrod with a ball formation on its free end extends from the motor mounting boss. Within the motor housing is a 12-volt Direct Current (DC) servo motor, an electronic controller board that includes the motor logic circuits, and an integral screw-drive transmission. The headlamp leveling motor is connected to the vehicle electrical system through a dedicated take out and connector of the front fascia wire harness.
The headlamp leveling motor is serviced as a unit with the headlamp unit. The motor cannot be repaired and, if ineffective or damaged, the entire headlamp unit must be replaced.
OPERATION
The controller board and logic circuitry of the headlamp leveling motor control motor operation based upon a voltage signal input received from the resistor multiplexed headlamp leveling switch on the instrument panel. When the motor is energized it will extend or retract the motor pushrod through the integral screw-drive transmission. The ball on the end of the pushrod is snapped into a socket on the back of the reflector within the headlamp unit housing, which will cause the reflector to move as the pushrod is extended or retracted, changing the angle at which the light is projected from the headlamps.
The headlamp leveling motors and switch have a path to ground at all times. The headlamp leveling components operate on battery voltage received through the fused park lamp relay output circuit so that the system will only operate when the exterior lighting is turned On.
Because of active electronic elements within the headlamp leveling motor, it cannot be tested using conventional diagnostic tools and procedures. If the headlamp leveling system is believed to be ineffective, the headlamp leveling circuits and the leveling switch must be tested before considering motor replacement.