Citroen C5 Aircross Quiz
Exterior lighting / signalling

Dynamic headlamp levelling function

In this manual: Exterior lighting / signalling
AAS - Parking Aid — 8Owner's Manual Citroën C5 II — 139Citroen C5 Aircross (2017- 2024) - Owner's Manual — 143Audio system — 14Overspeed control — 7Multifunction display — 4Driver information instrument cluster — 20Navigation assistance — 8Intruder alarm — 7Mechanical specifications — 9Power supply — 8Electrical equipment — 13Lighting and electrical equipment — 3Immobiliser — 4Sunroof — 10Exterior lighting / signalling — 38Multiplexing — 7Air conditioning — 7Body — 6General specifications — 9Automatic gearbox control — 3Exterior mirrors — 10Airbags — 5Defrost — 6Underinflation — 6Interior lighting — 4Wipers / Washers — 6Window lifters — 11Cooling — 8Opening management — 7Cruise control — 5Suspension — 4Grip management — 1Paint — 2Exterior lighting control — 1Indicators (turn signals) — 1Automatic lighting systems - General recommendations — 1Wiper control — 1Special position of the front wipers — 1
~1min read

Performance

The dynamic headlamp levelling corrector maintains the headlamp reflector aiming angle according to the vehicle's attitude. The function, active while driving or when stationary, prevents dazzling drivers of oncoming vehicles.

The suspension ECU calculates the reflector aiming angle based on the following parameters:

  • front and rear vehicle heights,
  • vehicle reference height (factory programmed),
  • vehicle wheelbase,
  • longitudinal acceleration.

Correction is active as soon as the low beams (xenon lamps) are switched on.

In degraded operation, the reflectors are automatically directed downward.

Block diagram: dynamic headlamp levelling function

Fonction correcteur dynamique de site projecteur
Dynamic headlamp levelling function

Key:

  • triple arrow: multiplexed link,
  • single arrow: wired link.
Description fonctionnelle : fonction correcteur dynamique de site

Functional description: dynamic headlamp levelling function

STEP

DETAILS
1 Front and rear height readings acquired by the suspension ECU
The suspension ECU acquires the longitudinal acceleration sent by the ABS ECU via the CAN network.
2 The suspension ECU knows the initial vehicle height as well as the wheelbase.

The suspension ECU determines whether the reflector needs to be adjusted. 3 The reflector tilt setpoint is sent to the left and right headlamp correctors. 4 The correctors decode the signal from the suspension ECU and drive the left and right reflector stepper motors.

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