GF54.65-P-0003CE Parktronic Function

GF54.65-P-0003CE PARKTRONIC Function
- with CODE (220) PARKTRONIC

General function requirements
^ Circuit 15 On

The circuit 15 status is sent by the electronic ignition lock control unit (N73) over the interior CAN (CAN B) to the PARKTRONIC control unit (N62).

PARKTRONIC, general
The PARKTRONIC system is an ultrasonic measuring program, used to determine how far away the vehicle is 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 PARKTRONIC system is activated again when it was manually switched off during the last journey using the PARKTRONIC button (N72/1s8).

The PARKTRONIC system consists of the following subfunctions:
^ Self-test function sequence
^ Function sequence for PARKTRONIC activation and deactivation
^ Reverse travel function sequence
^ Forward travel function sequence

Its operating principle (transmission and reception of sound waves), means that it will be unable to function properly in certain situations. 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 PARKTRONIC control unit performs a self-test after the ignition (circuit 15 ON) is switched on.
The following components are checked for proper operation:
- PARKTRONIC control unit
- Rear PARKTRONIC warning indicator (A44/3)
- Dashboard PARKTRONIC warning indicator (A44/4)
- Front PARKTRONIC distance sensor
- Outer left front PARKTRONIC distance sensor (B8/1)
- Center left front PARKTRONIC distance sensor (B8/2)
- Inner left front PARKTRONIC distance sensor (B8/3)
- Inner right front PARKTRONIC distance sensor (B8/4)
- Center right front PARKTRONIC distance sensor (B8/5)
- Outer right front PARKTRONIC distance sensor (B8/6)

- Rear PARKTRONIC distance sensors
- Outer right rear PARKTRONIC distance sensor (B8/7)
- Inner right rear PARKTRONIC distance sensor (B8/8)
- Inner left rear PARKTRONIC distance sensor (B8/9)
- Outer left rear PARKTRONIC distance sensor (B8/10)

- All PARKTRONIC electrical lines

Following the self-test, all the LEDs in 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 PARKTRONIC control unit performs further self-tests at regular intervals. The PARKTRONIC system distinguishes between a malfunction and a system error.
In the event of a malfunction or system error, the PARKTRONIC system is deactivated and the LED in the PARKTRONIC button in the upper control panel control unit (N72/1) lights up.

The following states can be recorded:
^ Operational problem
^ System error(s)

Operational problem
A malfunction can be caused by a temporary external disturbance (e.g. a jackhammer on a construction site, a steam jet or by driving through an automatic car wash). If a malfunction occurs during operation, this is displayed by the red LEDs on the respective PARKTRONIC warning indicator lighting up.
If a system error is present for an extended period of time, the cause of the malfunction is identified during driving by means of a self-test. If the malfunction is still present, this is interpreted as a system error.

A warning sound is not emitted.

System fault
A system fault can have the following causes:
- Defective component
- CAN communication fault
- Overvoltage or undervoltage

If a system error is detected, the red LEDs of the respective PARKTRONIC warning indicator are actuated. A warning tone is also emitted for t = 2 s.

Following a further t = 20 s the PARKTRONIC system shuts down and an error is written to the fault memory in the PARKTRONIC control unit.

Additional function requirements for PARKTRONIC 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 directly read in by the front SAM control unit with fuse and relay module (N10/1) and transmitted to the PARKTRONIC control unit over the interior CAN.

Function sequence for PARKTRONIC activation and deactivation
The PARKTRONIC button in the upper control panel control unit enables the PARKTRONIC system to be manually activated or deactivated. If the PARKTRONIC system is deactivated, the LED in the PARKTRONIC button is actuated.
Any actuation of the PARKTRONIC button is forwarded by the upper control panel control unit over the instrument panel LIN (LIN 1) to the front SAM control unit. This then transmits the status to the PARKTRONIC control unit over the interior CAN.

When the PARKTRONIC system is activated, and depending on the status of the light sensor (B38/1) (without code (345) Rain sensor) or the rain/light sensor (B38/2) (with code (345) Rain sensor) the respective PARKTRONIC warning indicator is actuated at a specific brightness level. The status of the light sensor or the rain/light sensor is sent over the wiper/inside rearview mirror-LIN (LIN 2) to the front SAM control unit, which then forwards the signal over the interior CAN to the PARKTRONIC control unit. If the light sensor or rain/light sensor determines that it is "Night", then the warning indicators are actuated at 30 % brightness. During the "day" the warning indicators are actuated at 100 % brightness. When driving the PARKTRONIC system switches to standby mode between v = 16 and 40 km/h. In other words, the PARKTRONIC control unit, the PARKTRONIC warning indicators and the PARKTRONIC distance sensors are supplied with voltage, but the PARKTRONIC warning indicators are not yet actuated.







Monitoring range diagram (Shown on model 204.0)
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 a maximum of s = 100 cm (a), the monitoring range behind the vehicle is a maximum of s = 120 cm (b).
If the distances are less than s = 20 cm (C1, C2), PARKTRONIC system does not receive any more defined values due to technological limitations.

The outer left and right front PARKTRONIC distance sensors 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.
Distance sensors are not installed for corner protection in the swivel range of the vehicle at the rear because these areas can be viewed using the outside mirrors.

Additional function requirements for reverse travel
^ v < 16 km/h
^ Reverse gear engaged

Reverse travel function sequence
During reverse travel the areas in front of and behind the vehicle are monitored.
The reverse gear signal is sent as follows:
On model 204.0/2 with transmission 711, 716:
The status of the backup lamp switch (S16/2) is directly read in by the front SAM control unit and sent over the interior CAN to the PARKTRONIC control unit.

On transmission 722:
The reverse travel signal is generated by the electronic selector lever module control unit (N15/5) and sent over the drive train CAN (CAN C) to the ME-SFI [ME] control unit (N3/10) (for gasoline engine) or to the CDI control unit (N3/9) (for diesel engine). This information is then sent over the chassis CAN (CAN E) to the front SAM control unit, when then forwards it over the interior CAN to the PARKTRONIC control unit.

The signals of the left front axle rpm sensor (L6/1), right front axle rpm sensor (L6/2), left rear axle rpm sensor (L6/3) and right rear axle rpm sensor (L6/4) are read in by the Electronic Stability Program control unit (N30/4) and sent over the chassis CAN to the instrument cluster (A1).
The instrument cluster uses the information from the rpm sensors to generate the vehicle speed signal and sends it over the interior CAN to the PARKTRONIC control unit.

When the vehicle drops below the lower limit speed of 16 km/h, the PARKTRONIC system 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 LEDs in the PARKTRONIC warning indicators.
When the range drops below a distance s < 30 cm, the warning is emitted initially as an intermittent tone and then as a continuous signal (see table below). When the upper speed limit of v = 18 km/h is exceeded the PARKTRONIC system changes over to standby mode again.

On vehicles with code (550) Trailer hitch, the area to the rear of the vehicle is not monitored when a trailer used. The trailer recognition control unit (N28/1) sends a "Trailer detected" status over the interior CAN to the front SAM control unit, which then forwards the status over the interior CAN to the PARKTRONIC control unit.

Warning Messages In The Front Monitoring Range, In The PARKTRONIC Warning Indicator Instrument Panel:

Warning Messages In The Rear Monitoring Range, In The Rear PARKTRONIC Warning Indicator:

Additional function requirements for forward travel
^ Vehicle speed v < 16 km/h
^ Drive position "D" engaged (for transmission 722)

The vehicle speed is recorded through the rpm sensors. The rpm sensor signals are read in by the Electronic Stability Program control unit and sent over the chassis CAN to the instrument cluster. The instrument cluster uses them to generate a vehicle speed signal, which is then sent over the interior CAN to the PARKTRONIC control unit.

The engaged gear range "D" is generated by the electronic selector lever module control unit and sent over the drive train CAN to the ME-SFI [ME] control unit or to the CDI control unit. This information is then sent over the chassis CAN to the front SAM control unit, when then forwards it over the interior CAN to the PARKTRONIC control unit.

Forward travel function sequence
When driving forwards the area in front of the vehicle is monitored. In a vehicle speed range of v = 0 to 16 km/h the PARKTRONIC system switches to the measuring mode. If obstacles are detected in front of the vehicle, the driver is alerted first visually by illumination of the corresponding LEDs in the PARKTRONIC warning indicator.
When the range drops below a distance s < 30 cm, the warning is emitted initially as an intermittent tone and then as a continuous signal (see table above).
When the upper speed limit of v = 18 km/h is exceeded, the PARKTRONIC system changes over to standby mode again.