GF54.65-D-0001H Parktronic System (PTS), Function

GF54.65-D-0001H Parktronic System (PTS), Function

- with CODE (EZ8) Parktronic system (PTS)

The Parktronic system (PTS) is an electronic parking assist system.
It assists the driver to better estimate the distances to obstacles in front of and behind the vehicle, particularly in blind areas. During forward travel the PTS only monitors the front area, whereas when reversing and when in neutral (rolling backwards) the rear-end is also monitored.
The following function conditions must be met:
- Parking brake disengaged
- Circuit 15 ON
- The selector lever is not in "P" (valid for automatic transmission 722.6 only)
- Vehicle speed is v ≤ 16 km/h
- The PTS OFF button (N72/1s9) in the OBF control unit (N72/1) is deactivated

The PTS consists of the following main components:
- 10 ultrasonic sensors (4 sensors in the rear and 6 sensors in the front bumper)
- One PTS control unit (N62)
- One PTS OFF button with light emitting diode (LED) status indicator located in the OBF control unit
- One center front PTS warning element (A44/9)
- 2 front Parktronic warning indicators at left and right front, integrated into the outside mirrors

Function
After the status "circuit 15 ON" the PTS actuates the center front Parktronic system warning element and the left front and right front Parktronic warning indicators for t = 1 s, i.e. all LEDs light up for 1 s.
This then visually confirms that the system functions correctly. The PTS control unit, the sensors and the lines to the sensors, the center front PTS warning element and the left front and right front Parktronic warning indicators as well as the lines to the center front Parktronic system warning element and the left front and right front Parktronic warning indicators are checked. Die The readiness for operation of the PTS is displayed by the warning element through the lighting up of the inner yellow bar (standby).
Obstacles on the PTS is displayed by the center front PTS warning element and the front Parktronic warning indicator at left and right front. The center front PTS warning element for the front area is positioned on the cockpit and the front Parktronic warning indicator at left and right front for the rear area is mounted in each case at the left and right in the outside mirrors. There is therefore a left and a right-hand scanning area before or to the rear of the vehicle.

The smaller the distance of an obstacle to the bumper, the more light spots are activated.
The measuring range of the front or rear vehicle corners first starts at a distance of 65 cm in the front area,or 75 cm in the rear area. The display area encompasses 7 LEDs, whereby 5 yellow LEDs cover an obstacle distance of approx. 100 cm in the front area or 180 cm in the rear area, up to 40 cm to the bumper. The area from 40 cm to 30 cm is displayed using 2 red LEDs. At distances less than 40 cm an acoustic warning is also emitted over the PTS buzzer (A44/12). First (first red LED) an intermittent tone is output, with increases proximity a continuous signal (second read LED). To clearly differentiate between the front and rear sound warning different frequencies have been specified.

After the ultrasonic signal is transmitted the respective sensor switches off briefly, in order to not detect the overshoot of the respective sensor membrane as a reflected signal (=obstacle) by mistake.
As a result the respective sensor is "blind" briefly, obstacles, which are very close to the respective sensor, can therefore not be detected due to the too small runtime of the sound.

Fault display
An active fault is displayed to the driver by the PTS on the center front PTS warning element and the left front and right front Parktronic warning indicators. The display is always independent of the fault type (e.g. sensor) and only takes place on the active front center PTS warning element and the active left front and right front Parktronic warning indicators. In the process the PTS runs through the so-called fault display cycle (for t = 2 s display from 2 red LEDs with continuous signal, then for t = 18 s display from 2 red LEDs without signal).

If the fault cycle has elapsed, the PTS changes to the inactive status (center front PTS warning element and left front Parktronic warning indicators dark and the PTS function indicator lamp in the PTS OFF button switched on).
A fault display only takes place when the PTS is active (measurement active, distance display on the center front PTS warning element and the left front and right front Parktronic warning indicators). Otherwise the center front PTS warning element and the left front and right front warning indicators are switched dark (inactive). Once the vehicle cycle has run through completely or a time of at least t = 20 s has expired, then an active fault is not displayed again after the PTS is activated (e.g. cut-off speed dropped below).
Instead of this the PTS changes immediately to the inactive state. This state is held in a nonvolatile memory (Erasable Programmable Read Only Memory (EPROM)). If the fault display cycle is not completed it runs again from the start.

Malfunction display
In the event of an active fault this is displayed to the driver for t = 20 s without sound on the center front active PTS warning element and the left front and right front active Parktronic warning displays. If the fault cycle has elapsed, the PTS changes to the inactive status (center front PTS warning element and left front Parktronic warning indicators dark and the LED in the PTS OFF button switched on). A fault is only displayed if the PTS is active (measurement active, distance display on the center front PTS warning element and the left front and right front Parktronic warning indicators), otherwise the center front Parktronic system warning element and the left front and right front Parktronic warning indicators remain switched dark (inactive). If the malfunction display cycle is finished or has expired for at least t = 5 s, the PTS immediately switches to the inactive status.

Because a malfunction is always viewed to be a temporary state, the "malfunction cycle completed" status is not saved. The consequence of this that following any change in the terminal 15 status, the malfunction display cycle runs again from the start. This does not apply when the cutoff speed is dropped below, because any malfunction during the sensor test changes to a fault. If the malfunction finishes within the time period of the malfunction display cycle, then it is interrupted and the PTS changes to the currently active status. This occurs at the latest after t = 5 s.

Diagnosis takes place via STAR DIAGNOSIS.
With trailer operation, with code (Q22) Trailer hitch, non- removable ball head or with code (Q50) Trailer hitch, removable ball head, the left front and right front Parktronic warning indicators are deactivated automatically)