GF88.50-P-0008RIT Rear Wing, Function

GF88.50-P-0008RIT Rear Wing, Function
- with CODE (P99) Special model "AMG Black Series"

General function requirements
^ Circuit 15 On

The status of c. 15 is transmitted by the EIS control unit (N73) to the AMG DRIVE UNIT control (N145) via the interior CAN.

Rear wing, general
The rear wing is intended to adapt the contact pressure of the vehicle in various vehicle speed ranges. The rear wing is moved by two hydraulic cylinders in the trunk lid. The hydraulic volume flow is generated by the rear wing hydraulic pump (M87). The rear wing is controlled by the AMG DRIVE UNIT drive unit.

The rear wing function comprises the following subfunctions:
^ Function sequence for rear window manual adjustment
^ Function sequence for rear window automatic adjustment
^ Function sequence for rear window position monitoring
^ Function sequence for visual feedback

Additional function requirements for rear wing manual adjustment
^ Vehicle speed v < 120 km/h

The vehicle speed is transmitted by the instrument cluster (A1) to the AMG DRIVE UNIT control via the interior CAN.

Function sequence for rear window manual adjustment
The rear window can be adjusted manually below a vehicle speed of v = 120 km/h via the rear wing button (S16/14s2). The status of the rear wing button is read in by the AMG DRIVE UNIT control unit. When the rear wing button is actuated momentarily, the rear window extends completely. When the rear wing button is actuate for a longer period of time, the rear wing retracts. Hold down rear wing button until lower end position of rear wing is reached. If the rear wing button is released before the end position is reached, the rear wing reverses direction.

The AMG DRIVE UNIT control actuates, the rear wing hydraulic pump via the rear wing lifting relay (K112k1) or rear wing lowering relay (K112k2) depending on the request.

If the trunk lid is opened while the rear wing is extending, the rear wing extends completely. The rear wing, however, can only be retracted after the trunk lid is closed.

If the trunk lid is opened while the rear wing is retracting, the rear wing stops immediately. If the trunk lid is closed again, the rear wing extends completely.

The status of the trunk lid is sensed by the lock pawl rotary tumbler switch (S88/4). The rear SAM control unit(N10/8) reads in the status of the lock pawl rotary tumbler switch and transmits the data to the AMG DRIVE UNIT control via the interior CAN.

Additional function requirements for rear wing automatic adjustment
^ Vehicle speed v > 120 km/h

Function sequence for rear window automatic adjustment
The rear wing is extended automatically when a vehicle speed of v = 120 km/h is exceeded. Manual adjustment is no longer possible. If a vehicle speed of v = 60 km/h is surpassed, the rear wing is retracted automatically. The AMG DRIVE UNIT control actuates, the rear wing hydraulic pump via the rear wing lifting relay or rear wing lowering relay depending on the request.

Function sequence for rear window position monitoring
The rear wing positions are sensed by the following sensors:
- Left upper position sensor (B87/1)
- Right upper position sensor (B87/2)
- Left bottom position sensor (B87/3)
- Bottom right position sensor (B87/4)

The AMG DRIVE UNIT control reads in the signals from the position sensor for position monitoring. If implausible rear wing positions are sensed, a corresponding error message is indicated in the instrument cluster.

Function sequence for visual feedback
The visual feedback comprises the following subfunctions:
^ Function sequence for feedback via rear wing status LED
^ Function sequence for feedback via instrument cluster

Function sequence for feedback via rear wing status LED
The rear wing status is indicated via the rear wing status LED (S16/14e1). The following states are possible:
- LED off, rear wing is retracted
- LED flashes, rear wing is in intermediate position
- LED on, rear wing is extended

Function sequence for feedback via instrument cluster
The following messages are displayed on the instrument cluster:
- In the right multifunction display (A1p15) when manually retracting rear wing: "Warning. Rear wing retracts."

First a pictogram of the spoiler with arrow down appears in the left multifunction display (A1p13).

- In the right multifunction display with defective rear wing or defective rear wing control: "Rear spoiler control defective! Please visit workshop."

An acoustic warning signal sounds together with messages in the instrument cluster.

Message "Rear spoiler control" defective. Please visit workshop." can be reset manually. When the rear wing button is actuated for t = 10 s, with c. 15 R, the fault memory is erased. After t = 10 s the rear wing status LED flashes continuously.