GF54.65-P-0003LE Parktronic Function
GF54.65-P-0003LE PARKTRONIC Function
- with CODE (220) PARKTRONIC
General function requirements
^ Circuit 15 On
PARKTRONIC, general
The PARKRONIC system is an ultrasonic measuring system for recording the distance of the vehicle from 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 PARKRONIC system is also reactivated when it was switched off manually via the PTS OFF switch (S6/2s12) on the last journey.
The PARKRONIC system is comprised of the following part functions:
^ Self-test function sequence
^ Activate and deactivate function sequence
^ Reverse travel function sequence
^ Forward travel function sequence
Malfunctions can occur in certain cases due to the function principle (transmitting and receiving sound waves). So it can occur that incorrect values are displayed when an obstacle which absorbs a lot of sound is approached (e.g. a vehicle covered by snow).
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)
- Front PTS ultrasonic sensors
- Outer left front PTS ultrasonic sensor (B8/1)
- Center left front PTS ultrasonic sensor (B8/2)
- Inner left front PTS ultrasonic sensor (B8/3)
- Inner right front PTS ultrasonic sensor (B8/4)
- Center right front PTS ultrasonic sensor (B8/5)
- Outer right front PTS ultrasonic sensor (B8/6)
- Rear PTS ultrasonic sensors
- Outer right rear PTS ultrasonic sensor (B8/7)
- Inner right rear PTS ultrasonic sensor (B8/8)
- Inner left rear PTS ultrasonic sensor (B8/9)
- Outer left rear PTS ultrasonic sensor (B8/10)
- all electrical lines of the PARKTRONIC system
After the self-test the rear warning indicator is actuated directly and completely for approx. t = 1 s by the PTS control unit.
For a front warning indicator display the PTS control unit transmits the request via the interior CAN to the central gateway control unit (N93) and again via the central CAN to the instrument cluster (A1). If there are no malfunctions or system faults present, the two yellow horizontal "Standby" bars of the warning indicator in the multifunction display (A1p13) of the instrument cluster light up and the two inner yellow light-emitting diodes in the rear warning indicator light up with reduced brightness The background illumination of the warning indicators is automatically adjusted to suit the ambient brightness.
The PTS control unit carries out further self-tests at regular intervals.
The PTS control unit distinguishes between a malfunction and a system fault. In the event of a system fault or malfunction the PARKTRONIC system is deactivated and the red light-emitting diodes of the warning indicator affected are actuated.
The following states can be recorded:
^ Operational problem
^ System error(s)
Operational problem
A malfunction can be caused by a temporary disturbance from outside (e. g. compressed air hammer on a construction site, steam clean or car wash way through).
If a malfunction occurs in operation, this is displayed by the lighting up of the red display elements or the red light-emitting diode of the respective warning indicator affected.
If the malfunction is present over a longer period of time, the cause is identified by a self-test while driving. If the malfunction continues, 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 of the respective warning indicator affected are actuated.
A warning tone is also emitted for t = 2 s.
After a further t = 20 s the PARKTRONIC system switches off and a fault is entered in the fault memory of the PTS control unit.
Additional function requirements - activation and deactivation
^ Self-test completed successfully
^ Parking brake not operated
The status of the parking brake is read in via the electric parking brake switch (S76/15) by the electric parking brake controller unit (A13). The controller unit transmits this signal to the central gateway control unit via the front end CAN. From there the signal is transmitted to the PTS control unit via the interior CAN.
Activate and deactivate function sequence
The PTS is deactivated or activated manually via the PTS OFF switch in the cockpit switch group (S6/2). If the system is deactivated, the function light-emitting diode is actuated in the PTS OFF switch. The status of the cockpit switch group is read in by the upper control panel control unit (N72/1) via the instrument LIN. The upper control panel control unit passes on the status of the PTS OFF switch to the PTS control unit via the interior CAN.
When the PTS is activated theB38/2 warning indicators are actuated with a particular brightness depending on the status of the rain/light sensor.
The status of the rain/light sensor is read in by the overhead control panel control unit (N70) and transmitted to the PTS control unit via the interior CAN. If the rain/light sensor detects "Night", the warning indicators are actuated at 30 % brightness. During the day" the warning indicators are actuated at 100 % brightness. While driving, the PARKTRONIC system switches to standby mode at a vehicle speed between v = 16 and 40 km/h, i.e. the PTS control unit, warning indicators and distance sensors are supplied with voltage but the warning indicators are not yet actuated.
The illumination of the rear warning indicator is regulated by the PTS control unit. The illumination of the warning indicator in the multifunction display is controlled by the instrument cluster.
Display of monitoring range (shown on model 221.0)
When gear range "D" is engaged the monitoring range (A) in front of the vehicle is monitored, when gear range "R" or "N" is engaged the monitoring ranges (A, B) in front of and behind the vehicle are monitored.
The monitoring range in front of the vehicle is a maximum of 100 cm (a), the monitoring range behind the vehicle is a maximum of 120 cm (b).
If the distances are less than 20 cm (c1, c2) the PTS control unit does not receive any further defined values for technical reasons.
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 - reverse travel
^ Reverse gear engaged
^ Vehicle speed v < 16 km/h
Reverse travel function sequence (Front and rear monitoring ranges active)
The status of the gear selector switch DIRECT SELECT (S16/13) is read in by the steering column tube module (N80) and transmitted on the chassis CAN.
The ETC [EGS] control unit (N15/3) (with transmission 722.6) or fully integrated transmission control unit (VGS) (Y3/8n4) (with transmission 722.9) transmit "Reverse gear engaged" via the drive train CAN to the CDI control unit (N3/9) (with diesel engine) or to the motor electronics control unit (N3/10) (with gasoline engine) which passes on the request to the central gateway control unit (N93) via the chassis CAN.
The central gateway control unit passes on the signal "Reverse gear engaged" to the PTS control unit via the interior CAN.
The vehicle speed is calculated in the instrument cluster from the signals from the left front rpm sensor (L6/1), right front rpm sensor (L6/2), the left rear rpm sensor (L6/3) and the right rear rpm sensor (L6/4).
The signals from the rpm sensor are read in by the ESP control unit (N47-5) and transmitted to the central gateway control unit via the chassis CAN.
The instrument cluster receives the signals from the central gateway control unit via the central CAN and evaluates them. Afterwards the instrument cluster transmits the vehicle speed signal to the central gateway control unit via the central CAN. The vehicle speed signal is passed on to the PTS control unit via the interior CAN.
When the lower limit speed of v = 16 km/h is dropped below, the PARKTRONIC system changes to measuring mode. When obstacles are detected in front of or behind the vehicle this is first conveyed to the driver by the lighting up of the corresponding light-emitting diodes in the warning indicators.
When a distance of s < 30 cm is dropped below the warning is first output by an intermittent tone, then by a continuous signal (see preceding tables). When a vehicle speed of v = 18 km/h is exceeded the PARKTRONIC system switches into Standby mode again.
Any switched-on audio sources are muted for the duration of the acoustic warning by the COMAND controller unit (A40/3).
On model 221 with code (550) Trailer hitch the area behind the vehicle is not monitored during trailer operation. The trailer recognition control unit (N28/1) transmits the status "Trailer recognized" to the PTS control unit via the interior CAN.
Warning Messages In The Front Monitoring Range, In The Warning Indicator Of The Malfunction Display In The Instrument Cluster:
Warning Messages In The Rear Monitoring Range, In The Rear PTS Warning Indicator:
Additional function requirements - forward travel
^ Vehicle speed v < 16 km/h
The vehicle speed is recorded via the rpm sensors. The speed sensor signals are transmitted from the ESP control unit to the central gateway control unit via the chassis CAN. The instrument cluster receives the signals from the central gateway control unit via the central CAN. The instrument cluster generates a speed signal from this which is transmitted back to the central gateway control unit and is passed on from there to the PTS control unit via the chassis CAN.
Forward travel function sequence (Front monitoring active)
When the lower limit speed of v < 16 km/h PARKTRONIC changes over to measuring 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 a distance of s < 30 cm is dropped below the warning is first output by an intermittent tone, then by a continuous signal (see preceding tables).
When the vehicle speed of v = 18 km/h is exceeded the PTS changes over to standby mode.
