GF54.65-P-0003RI Parktronic Function
GF54.65-P-0003RI PARKTRONIC Function
- with CODE (220) PARKTRONIC
General function requirements
^ Circuit 15 On
Parktronic system (PTS), general
The PTS is an ultrasonic measuring system for detecting the distance from the vehicle to an obstacle. It assists the driver when parking and in maneuvering situations at speeds of v < 16 km/h. The distance between the vehicle and the obstacle is indicated to the driver visually and acoustically.
The PTS is always reactivated even if it was manually deactivated during the last journey using the PTS OFF switch (N72s13).
The PTS comprises the following subfunctions:
^ Self-test function sequence
^ Activate and deactivate function sequence
^ Reverse travel function sequence
^ Forward travel function sequence
^ Rolling backwards on a slope function sequence
Due to the principle on which it operates (transmission and reception of sound waves), the PTS cannot function properly in certain situations. For example, incorrect values may be displayed when the vehicle approaches an obstacle which absorbs sound very effectively (a snow-covered vehicle).
Self-test function sequence
The PTS control unit (N62) performs a self-test when the ignition is switched on (circuit 15 ON).
The following components are checked for proper operation:
- PTS control unit
- Rear PTS warning indicator (A44/3)
- Center dashboard PTS warning indicator (A44/4)
- Front PTS ultrasonic sensors (B8/1, B8/2, B8/3, B8/4, B8/5, B8/6)
- Rear PTS ultrasonic sensors (B8/7, B8/8, B8/9, B8/10)
- All electrical lines of PTS
Following the self-test, all display elements of the warning indicators are fully actuated for t = approx. 1 s.
If there are no malfunctions or faults present, the two yellow horizontal standby bars of the two warning indicators illuminate at reduced brightness. The background illumination of the warning indicators is automatically adjusted to suit the ambient brightness.
The PTS control unit performs further self-tests at regular intervals. The PTS distinguishes between disturbances and system faults. In the event of a system fault or system disturbance, the PTS is deactivated and the display element in the PTS OFF switch in the lower control panel control unit (N72) lights up.
The following states can be recorded:
^ System disturbance
^ System fault
System disturbance
A system disturbance can be caused by a temporary external disturbance (e.g. a jackhammer on a construction site, a steam jet or by driving through a washing facility). If a system disturbance occurs during operation, this is indicated by illumination of the red display elements in each affected warning indicator.
If a system disturbance is present for an extended period of time, the cause of the system disturbance is identified during driving operation by means of a self-test. If the system disturbance is still present, this is interpreted as a system fault.
A warning sound is not emitted.
System fault(s)
A system fault can have the following causes:
- Defective component
- CAN communication fault
- Overvoltage or undervoltage
If a system fault is detected, the red display elements in each affected warning indicator are actuated. A warning tone is also emitted for t = 2 s.
Following a further t = 20 s the PTS shuts down and a fault is written to the fault memory in the PTS control unit
Additional function requirements for activation and deactivation
^ Self-test completed successfully
^ Parking brake not operated
The status of the parking brake is detected via the parking brake indicator switch (S12). The status of the parking brake indicator switch is read in directly by the driver-side SAM control unit (N10/10) and sent via the interior CAN to the PTS control unit.
Activate and deactivate function sequence
The PTS can be manually deactivated or activated by actuating the PTS OFF switch in the lower control panel control unit. The status of the PTS OFF switch is read in by the lower control panel control unit and forwarded to the PTS control unit via the interior CAN.
The warning indicators are actuated according to the ambient brightness. The intensity of the ambient brightness is recorded by the rain/light sensor (B38/2). The status of the rain/light sensor is read in by the overhead control panel control unit (N70) and transmitted via the interior CAN to the PTS control unit. At "night" the warning indicators are actuated at 30 % brightness. During the "day" the warning indicators are actuated at 100 % brightness.
In the vehicle speed range of v = 40 to 16 km/h, the PTS switches to standby mode. The PTS control unit, the warning indicators and the ultrasonic sensors are supplied with voltage but the warning indicators are not actuated.
When the PTS is deactivated, the display element in the PTS OFF switch lights up.
During forward travel the monitoring range (A) is in front of the vehicle, during reverse travel the monitoring range (A, B) is in front of and behind the vehicle.
The monitoring range in front of the vehicle is max. s = 100 cm (a) and behind the vehicle max. s = 120 cm (b).
If the distances in the monitoring ranges (C1, C2) are less than s = 20 cm, the PTS does not receive any more defined values due to technical limitations.
The outer left front PTS ultrasonic sensor and outer right front PTS ultrasonic sensor are used for protecting corners in the swivel range of the vehicle front. A minimum distance of s = 15 cm applies to the monitored range at these locations and it is implemented by means of software.
Ultrasonic sensors are not installed for corner protection in the swivel range of the vehicle at the rear because these areas can be seen using the outside mirrors.
Additional function requirements for reverse travel
^ v < 16 km/h
^ Reverse gear engaged
The vehicle speed is defined via the signals of the rpm sensors (L6/1, L6/2, L6/3 and L6/4). The signals of the rpm sensors are read in by the SBC hydraulic unit (A7/3) and forwarded directly to the ESP, SPS [PML] and BAS control unit (N47-5). The ESP, SPS [PML] and BAS control unit transmits them to the instrument cluster (A1) via engine compartment CAN.
The instrument cluster uses these to generate the vehicle speed and transmits this to the PTS control unit via interior CAN. The status of the selector lever is transmitted by the electronic selector lever module control unit (N15/5) to the EZS control unit (N73) via engine compartment CAN. The EZS control unit uses this to generate the reverse gear signal and transmits it to the PTS control unit via interior CAN.
Reverse travel function sequence (Front and rear monitoring ranges active)
When the vehicle drops below the lower limit speed of 16 km/h, the PTS changes to measurement mode.
If obstacles are detected in front of or behind the vehicle, the driver is first alerted visually by illumination of the corresponding display elements in the warning indicators. When the range drops below a distance s = 30 cm, the warning is emitted as an intermittent tone and then as a continuous signal (see tables below).
If a vehicle speed of v = 18 km/h is exceeded, PTS returns to standby mode.
Warning Messages In The Front Monitoring Range On The Center Instrument Panel PTS Warning Indicator:
Warning Messages In The Rear Monitoring Range On The Rear PTS Warning Indicator:
Additional function requirements for forward travel
^ v < 16 km/h
Forward travel function sequence (Front monitoring active)
When the vehicle drops below the lower limit speed of 16 km/h, the PTS changes to measurement mode.
If obstacles are detected in front of the vehicle, the driver is first alerted visually by illumination of the corresponding display elements in the warning indicator. When the range drops below a distance s = 30 cm, the warning is emitted as an intermittent tone and then as a continuous signal (see tables above). If a vehicle speed of v = 18 km/h is exceeded, PTS returns to standby mode.
Additional function requirements for rolling backwards on a slope
^ Reverse gear not engaged
Rolling backwards on a slope function sequence
When the reverse gear is not engaged, the rear area of the vehicle is not monitored. The vehicle could thus roll back unnoticed and hit an obstacle without warning. To prevent this, the rear monitoring range is automatically activated over a distance of s = 15 cm if the vehicle rolls backwards.
Backwards rolling movement is defined by the signals of the rpm sensors. The SBC hydraulic unit reads in the signals of the rpm sensors and forwards them directly to the ESP, SPS [PML] and BAS control unit. The ESP, SPS [PML] and BAS control unit transmits them to the EZS control unit via engine compartment CAN.
The EZS control unit makes them available to the PTS control unit on the interior CAN. If the vehicle approaches an obstacle, an appropriate warning message is output (see previous tables).
