Under the microscope: the electric running boards: Spectacular impact assured

Nov 21, 2019

One highlight of the Mercedes-Maybach GLS are the electrically extending running boards. They make accessing and leaving the high seating position both convenient and safe, and ensure an elegant spectacle.

The running boards painted in high-gloss black are each 2.06 metres long, and have a maximum width of 21 centimetres in the rear door areas – they are slightly narrower below the front doors. They occupy the entire length of the side sill panels. Black rubber strips are inset into their surfaces of anodised aluminium, with their contours echoing the oar-blade pattern from the radiator grille at the rear end. At the rear end of each running board there is also a chrome-look Mercedes-Maybach emblem.

When in the retracted position, the running board is almost invisibly concealed within the side sill panel. In this position it is inclined towards the centre of the vehicle by around 45°, and closely follows the side sill. This means that ground clearance is not compromised. When a side door is opened, the running board on the side concerned is first moved downwards silently and smoothly by two electrically powered arms of die-cast aluminium each with four articulation joints, and then moves outwards to a horizontal position. The time taken between operating the door handle and deployment of the running board is only roughly one second. In the dark, as an addition to the ambient illumination provided by the open doors, the running board surface in the rear door area is illuminated by an LED strip in the side sill panel, including projection of the Maybach emblem.

When the car is lowered by 25 mm by AIRMATIC when the door is opened, the distance between the road surface and the vehicle's underfloor is further reduced by the running board, making access and egress even easier. The anti-slip rubber strips ensure a secure foothold. The support structure of each running board is designed for a maximum load of 200 kg.

If a rear door is opened, the running board on the side concerned automatically swings outwards. This default setting can be changed at any time, using a special menu in the media display. For example, it is also possible to keep the running boards permanently retracted or only activated on manual instruction. In manual mode, the running boards can also be deployed when the doors are closed. If the vehicle is moving at more than 4 km/h, the running boards are automatically retracted. In the Off-Road drive program, the automatic function is always deactivated to avoid collisions with uneven surfaces. After the side door is closed, the running board retracts in around 1.5 seconds.

The kinematics and installed position of the running board ensure that on level surfaces, deployment and retraction of the running board is possible without constraint even in the low-level position of the AIRMATIC. For safety reasons the automatic function has sensors similar to those used in the anti-pinch protection systems of power windows or sliding sunroofs. The procedure is therefore automatically stopped if a collision occurs with an obstacle.