Headlamp Levelling

Headlamp Levelling

DESCRIPTION

Manual
Manual headlamp levelling is fitted to vehicles with conventional coil spring suspension system and halogen headlamps. The system is controlled via the rotary headlamp levelling switch, which is located on the instrument panel next to the lighting control switch. The switch operates motors located within both headlamp units to adjust headlamp position to allow for changes in attitude due to passenger or load distribution.

Automatic
Two forms of automatic headlamp levelling are fitted; Static and Dynamic.

Static Headlamp Levelling
Static headlamp levelling (also known as vehicle headlamp levelling) is only available on vehicles with air suspension. Operation of the static headlamp levelling system is controlled by the air suspension control module.

The suspension system constantly monitors the vehicle attitude and adjusts the height of the front and/or rear of the vehicle accordingly. This maintains the correct vehicle attitude and consequently maintains the correct headlamp alignment.

Dynamic Headlamp Levelling
Dynamic headlamp levelling is only available on vehicles with the Adaptive Front lighting System (AFS). The dynamic headlamp levelling system adjusts the vertical alignment of the headlamps as a rapid response to changes in vehicle attitude due to acceleration or braking.

NOTE: The dynamic headlamp levelling system also utilises the static headlamp levelling system as described previously.

Both the Static and Dynamic headlamp levelling systems are fully automatic, therefore the lighting control switch does not have the manual levelling rotary control.

OPERATION

Manual

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 11E (C0632) on an R wire. Fusible link 11E (C0570) is located in the Battery Junction Box (BJB) and is connected to the ignition switch (C0028) by an N wire. When the ignition switch is in the 'ignition' position, current flows across the switch (C0028) to fuse 27P and fuse 62P (C0582) on a Y wire. Both are located in the Central Junction Box (CJB). Fuse 27P (C0583) provides an ignition feed to the LH (C0009) and RH (C0011) headlamp levelling motors on a pair of RO wires.

Fuse 62P (C0583) provides an ignition feed to the lighting control switch (C0041) on an NP wire. The switch (C0041) is provided a ground path on a B wire.

Headlamp Levelling
The headlamp levelling switch is incorporated within the lighting control switch assembly. As the headlamp levelling switch is moved, the switch outputs a different output voltage. This voltage is provided to the LH (C0009) and RH (C0011) headlamp levelling units on YN wires.

The motors within the headlamp levelling units react to the voltage supplied by the lighting control switch and move the headlamps to the requested position. Both headlamps are provided a ground path on B wires.