Parking system, function - GF54.65-P-0006LE
MODEL 216.3 with CODE (220) PARKTRONIC with CODE (230) Advanced Parking Guidance as of model year 2011/YoM 10 model refinement package
MODEL 221.0 /1 with CODE (220) PARKTRONIC with CODE (230) Advanced Parking Guidance as of Model Year 2010/modification year 09 model refinement package
Function requirements, general
- Circuit 15 ON
- Circuit 61 ON (with parking space detection and parking guidance)
The status of circuit 15 is sent by the EZS control unit (N73) via the chassis CAN (CAN E) to the PTS control unit (N62).
The status of circuit 61 is sent by the CDI control unit (N3/9) (with diesel engine) or by the ME-SFI [ME] control unit (N3/10) (with gasoline engine) via the chassis CAN to the PTS control unit.
Parking system, general
The exclusive parking assist system assists the driver when parking and in maneuvering situations at speeds of v < 16 km/h. The parking system uses an ultrasound measuring system to record the distance from the vehicle to an obstacle, it is known as PARKTRONIC (with code (220) PARKTRONIC).
On vehicles with code (230) Exclusive parking assist, longitudinal parking spaces on both sides of the vehicle in the direction of travel are also measured and stored while the vehicle is moving at speeds of v < 36 km/h.
The exclusive parking assist system is an extension of the PARKTRONIC system and has larger detection areas.
The distance between the vehicle and the obstacle is indicated to the driver visually and acoustically.
Warnings from the parking system are disabled in some situations, e.g. when reversing into narrow passages (driveway). Although there is an obstacle in the detection area, there will be no collision owing to the current steering wheel position.
The parking system function consists of the following partial functions:
- Measuring procedure function sequence
- Self-test function sequence
- Behavior in the event of overvoltage and undervoltage function sequence
- Activate and deactivate function sequence
- Function sequence for reverse travel
- Forward travel function sequence
- Parking space recognition function sequence (with code (230) Exclusive parking assist)
- Display of potential parking spaces function sequence (with code (230) Exclusive parking assist)
- Parking Guidance function sequence (with code (230) Exclusive parking assist)
Illustration of the principle for measuring procedure
Measuring procedure function sequence
The parking system is based on the ultrasonic measuring procedure. The following components are actuated by the PTS control unit in the process:
- 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)
- 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)
As a result of this these emit an ultrasonic signal.
The signal reflected by an obstacle is received and evaluated. The respective distance of the vehicle to an obstacle is displayed to the driver via the PTS warning indicator in the instrument cluster (A1) and the rear PTS warning indicator (A44/3).
A distinction is made between two types of measurement: a) direct measurement resulting from a direct echo and b) indirect distance measurement which is achieved using a cross echo (illustration of the principle). Reflected echoes (known as "cross echoes") can usually also be received from adjacent ultrasonic sensors due to the large detection angles of the ultrasonic sensors. These occur at the obstacle due to scattered reflection.
The distance between the vehicle and obstacle can be calculated from two echo signals using the triangulation method. The propagation times of the signals from the direct measurement and from the cross measurement are required for this method.
The parking system cannot work correctly in certain cases due to the function principle (transmitting and receiving sound waves). So for example, when approaching a strong sound absorbent obstacle (e.g. a vehicle covered in snow) it is possible that false data may be displayed.
Monitoring zones with code (220) PARKTRONIC, shown on model 221
Monitoring zones with code (230) Exclusive parking assist, shown on model 221
The distance sensors are activated according to the direction of travel.
The appropriate distance sensors are activated with forward travel for monitoring the front area (A) and the corner protection area (B). The appropriate distance sensors are activated with reverse travel for monitoring the front area, the corner protection area and the rear area (C).
The monitored front area amounts to a maximum of s = 100 cm (c) and the monitored rear area amounts to a maximum of s = 120 cm (e). If the distance of the vehicle to an obstacle is less than s = 20 cm (a1, c1), the parking system will not obtain any more defined data for technical reasons.
For vehicles with code (230) Exclusive parking assist, the parking space detection area (D) to the left and right of the vehicle is scanned up to a distance of s = 400 to 450 cm (d) at a speed lower than v = 36 km/h and stored for s = 15 m in the PTS control unit.
Self-test function sequence
The PTS control unit performs a self-test when the ignition is switched on (circuit 15 ON).
The following components are checked for proper operation:
- PTS control unit
- Ultrasonic sensors
- Rear PTS warning indicator
- PTS warning indicator in instrument cluster
- Lines between PTS control unit, ultrasonic sensors and rear PTS warning indicator
PTS control unit self-test:
After ignition ON (circuit 15 ON), the PTS control unit performs a self-test. The hardware of the PTS control unit is tested during this test.
The self-test is performed irrespective of the status of the parking brake and selector lever position.
Ultrasonic sensor self-test:
A self-test of the ultrasonic sensors (e.g. for connection) is always performed whenever an ultrasonic sensor is "pulsed" (ultrasound is being transmitted).
The self-test depends on the status of the parking brake, selector lever position and speed.
Ultrasonic sensor test for reverberation:
An ultrasonic sensor test for reverberation (acoustic-physical function of the distance sensor) is only performed when the vehicle speed exceeds or drops below v = 60 km/h.
After the self-test, all display segments of the PTS warning indicator in the instrument cluster and all LEDs of the rear PTS warning indicator are fully actuated for approx. t = 1 s. If there are no malfunctions or faults present, the two yellow horizontal "standby" bars of the two PTS warning indicators light up with reduced brightness. The background illumination of the PTS warning indicators is automatically adjusted to the ambient brightness.
The PTS control unit performs further self-tests at regular intervals.
The parking system differentiates between a malfunction and a system error. In the event of a malfunction or system error, the parking system is deactivated and the display element in the PTS OFF switch (S6/2s12) lights up.
The following states can be recorded here:
- Operational problem
- System error(s)
Malfunction:
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 indicated by illumination of the red LEDs of each actuated PTS warning indicator.
If a malfunction exists any longer, identification of the cause takes place during driving operation via a self test. If the malfunction is still present, this is interpreted as a system error.
A warning sound is not emitted.
System fault(s)
A system fault can have the following causes:
- Defective component
- Error in communication
- Overvoltage or undervoltage
If a system error is detected, the red display elements of each actuated PTS warning indicator light up. An acoustic warning is also emitted for t = 2 s.
The parking system switches off after a further t = 18 s and a fault is entered in the fault memory of the PTS control unit.
The size of the license plate bracket attached to the bumper varies depending on the national version. Due to the different shapes and sizes of license plate brackets, the parking system must be adapted to the respective conditions. A diagnostic tester can be used to code the national version to prevent malfunctions caused by the license plate carrier.
Behavior in the event of overvoltage and undervoltage function sequence
The behavior of the parking system in the case of overvoltage or undervoltage is shown in the following table.
| On-board power supply voltage U < 9.0 V | On-board power supply voltage U > 16.0 V | Undervoltage with reset | Undervoltage without reset (Start pulse) |
|---|---|---|---|
| Parking system nonfunctional | Parking system nonfunctional | The function is activated again after a reset | Display of distance |
| PTS warning indicators dark | PTS warning indicators dark | No checking up of PTS warning indicators | Start pulse has no influence on parking system |
| No checking up if voltage is normal again | No checking up if voltage is normal again | - | No checking up of PTS warning indicators |
| Light-emitting diode in PTS OFF switch activated | Light-emitting diode in PTS OFF switch activated | - | - |
Additional function requirements for activation and deactivation
- Self-test completed successfully
- Parking brake not operated
Activate and deactivate function sequence
Actuation of the parking brake is detected via the electric parking brake switch (S76/15). The signal from the electric parking brake switch is read in by the electric parking brake controller unit (A13) and transmitted to the central gateway control unit (N93) via the front end CAN (CAN G). From here, the signal is passed on to the PTS control unit via the chassis CAN.
Actuation of the PTS OFF switch in the cockpit switch group (S6/2) is read in by the upper control panel control unit (N72/1) via the instrument panel LIN (LIN 1) and sent to the central gateway control unit via the interior CAN (CAN B). This transmits the status to the PTS control unit via the chassis CAN.
The parking system function is reactivated even if it was manually deactivated during the last journey using the PTS OFF switch.
With the parking system activated, the PTS warning indicators are actuated at a specific brightness depending on the ambient brightness. The ambient brightness is recorded by the rain/light sensor (B38/2).
The rain/light sensor is read in by the overhead control panel control unit (N70) which transmits the light status to the central gateway control unit via the interior CAN. This transmits the light status to the PTS control unit via the chassis CAN.
If the rain/light sensor detects "Day" the rear PTS warning indicator is actuated with 100 % brightness. In the case of "Night" the rear PTS warning indicator is actuated with 60 % brightness. The brightness of the front warning indicator is set using the brightness control of the instrument cluster.
When driving, the parking system switches to "standby" mode between v = 60 km/h and v = 16 km/h, i.e. the PTS control unit, PTS warning indicators and ultrasonic sensors are supplied with power, but the PTS warning indicators are not yet actuated.
Possible system statuses are listed in the following table.
| Status | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| PTS OFF switch | OFF | ON | ON | ON | ON | ON | ON | ||||
| Selector lever position | X | D, R or N | P | X | D, R or N | D | R or N | ||||
| v (in km/h) | X | ≥60 | X | X | V0 ≤V ≤ 60 | ≤VU | ≤VU | ||||
| Parking brake applied | X | X | X | Yes | X | no | no | ||||
| Wheel pulse counter signal | X | X | X | 0 (t = 2s) | X | X | X | ||||
| Light-emitting diode in PTS OFF switch | ON | OFF | OFF | OFF | OFF | OFF | OFF | ||||
| Front PTS ultrasonic sensors(1) | inactive | inactive | inactive | inactive | active for test, then inactive | active | active | ||||
| Rear PTS ultrasonic sensors(1) | inactive | inactive | inactive | inactive | active for test, then inactive | inactive | active | ||||
| PTS warning indicator in instrument cluster(1) | Dark (2) | OFF | dark | dark | active for test, then dark | ON | ON | ||||
| Rear PTS warning indicator(1) | dark | OFF | dark | dark | active for test, then dark | dark | ON | ||||
| D "Drive" R Backward N Neutral P Park position V Current speed V U Lower speed limit (v = 16 km/h) V O Upper speed limit (v = 18 km/h) Off Supply voltage switched off active Supply voltage applied and in operation dark PTS warning indicator supplied with power but dark inactive PTS ultrasonic sensors are supplied with voltage but do not emit any ultrasonic waves X Arbitrary condition/data |
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The ultrasonic sensors and PTS warning indicator are supplied with power. However, the ultrasonic sensors do not emit any ultrasonic waves and the PTS warning indicator is dark. Additional function requirements for reverse travel |
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- Vehicle speed v = 0 to 18 km/h or vehicle speed v = 16 to 0 km/h
- Reverse gear engaged or vehicle is rolling backward
The vehicle speed is recorded by the left front RPM sensor (L6/1), right front RPM sensor (L6/2), left rear RPM sensor (L6/3) and right rear RPM sensor (L6/4). The signals from the RPM sensors are sent by the ESP control unit (N47-5) (except model 221.095/195) or by the regenerative braking system control unit (N30/6) (model 221.095/195) via the chassis CAN to the PTS control unit.
The reverse travel function is requested by engaging gear range "R". The transmission position is made available on the drive train CAN (CAN C) by the intelligent servo module for DIRECT SELECT (A80) and passed on by the CDI control unit or by the ME-SFI [ME] control unit on the chassis CAN. The central gateway control unit reads in this information, generates from this the status "gear range R engaged" and transmits it to the PTS control unit via the chassis CAN.
Function sequence for reverse travel
During reverse travel the areas in front of and behind the vehicle are monitored. When the vehicle drops below the limit speed of v = 16 km/h, the parking system 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 rear PTS warning indicator or in the instrument panel.
When the distance drops below s = 30 cm, the warning is emphasized by means of an intermittent tone and then by means of a continuous signal (see the tables below). When the vehicle speed exceeds the upper limit speed of v = 18 km/h, the parking system switches back over to "standby" mode.
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) transmits the status "Trailer recognized" via the interior CAN to the central gateway control unit which transmits the status to the PTS control unit via the chassis CAN.
| PTS warning indicator in instrument cluster | Display element | Warning chime | Distance (cm) | |
|---|---|---|---|---|
| Ultrasonic sensor (B8/1, B8/6) | Ultrasonic sensor (B8/2, B8/3, B8/4, B8/5) | |||
| Visual | 1 (yellow) | - | - | < 100 |
| 2 (yellow) | - | - | < 80 | |
| 3 (yellow) | - | < 60 | < 65 | |
| 4 (yellow) | - | < 50 | < 50 | |
| 5 (yellow) | - | < 40 | < 40 | |
| Visual and acoustic | 6 (red) | Intermittent tone with f = 6 Hz | < 30 | < 30 |
| 7 (red) | Continuous signal | < 15 | < 20 | |
| Rear PTS warning indicator | Display element | Warning chime | Distance (cm) | |
|---|---|---|---|---|
| Ultrasonic sensor (B8/7, B8/10) | Ultrasonic sensor (B8/8, B8/9) | |||
| Visual | 1 (yellow) | - | - | < 120 |
| 2 (yellow) | - | - | < 95 | |
| 3 (yellow) | - | < 80 | < 75 | |
| 4 (yellow) | - | < 55 | < 55 | |
| 5 (yellow) | - | < 40 | < 40 | |
| Visual and acoustic | 6 (red) | Intermittent tone with f = 6 Hz | < 30 | < 30 |
| 7 (red) | Continuous signal | < 20 | < 20 | |
Additional function requirements for forward travel
- Speed v = 0 to 18 km/h or speed v = 16 to 0 km/h
Forward travel function sequence
When driving forwards the area in front of the vehicle is monitored. When the lower limit speed of v < 16 km/h is dropped below the parking system changes 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 of the PTS warning indicator in the instrument cluster.
When the distance drops below s = 30 cm, the warning is emphasized by means of an intermittent tone and then by means of a continuous signal (see the tables above).
When the vehicle speed exceeds v = 18 km/h, the parking system changes back to "standby" mode.
Additional function requirements, parking space recognition (with code (230) Exclusive parking assist)
- No trailer operation (with code (550) trailer hitch)
- No intervention by anti-lock braking system (ABS) or Electronic Stability Program (ESP) for t = 5 s
Parking space recognition function sequence (with code (230) Exclusive parking assist)
The parking space detection function is used for simple locating of suitable parallel parking spaces. The parking space detection function is implemented using the outer front ultrasonic sensors. These ultrasonic sensors monitor the area to the left and right of the vehicle and have a larger range than the other ultrasonic sensors.
In the vehicle speed range from v = 0 to 18 km/h, the parking system for parking space detection operates in mixed mode of the PARKTRONIC function and exclusive parking assist function. At speeds of v > 18 km/h, the parking system changes over to the parking space detection function and remains active up to v = 36 km/h.
The range of outer front ultrasonic sensors is a maximum of between s = 400 and 450 cm depending on environmental influences (e.g. rain, snowfall, air humidity, extreme temperature (T = -40 to +85°C), air pressure, hot engine air).
The data from the outer front ultrasonic sensors is read in and evaluated by the PTS control unit. Using the stored vehicle dimensions and the sizes of the detected parking spaces, the system calculates whether the parking space is suitable for the vehicle.
For a parking space to be recorded by the parking system, it must be:
- Parallel to the direction of travel
- At least b = 150 cm wide
- At least 100 cm longer than the vehicle
When a parking space is detected, the PTS control unit sends a request for visual indication via the chassis CAN to the central gateway control unit and then further via the central CAN (CAN F) to the instrument cluster. If the vehicle is brought to a standstill and reverse gear is engaged, the message "Pay attention to vehicle surroundings. Confirm with OK." appears in the instrument cluster. The PTS control unit sends the display data for parking guidance via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster only when actuation of the OK button (S110s6) has been sent by the steering column tube module (N80) via the chassis CAN to the PTS control unit.
Parking space recognition only recognizes a free space which is geometrically suitable for parking, not whether this free space actually also represents a parking space.
Illustration of principle of parking space detection, shown on model 221
The trajectory is the path that the vehicle is to follow into the parking space. The trajectory consists of two arcs.
Display of potential parking spaces function sequence (with code (230) Exclusive parking assist)
If a parking space is being sought, a P symbol (10) is shown in the instrument cluster. As soon as a suitable parking space is detected by the parking system, a LEFT arrow (11) or RIGHT arrow (12) appears in addition to this symbol to indicate on which side of the vehicle the parking space is located. Parking spaces are always looked for on both sides of the vehicle. However, only parking spaces on the passenger side are pointed out by default. To also allow parking spaces on the driver side to be displayed, the driver must actuate the turn signal in the appropriate direction.
The P symbol and the arrows are only active in gear range "D" in a vehicle speed range between v = 0 and 30 km/h.
The signal to activate the display in the instrument cluster is sent by the PTS control unit via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster. The switch position of the combination switch (S4) is read in by the steering column tube module and sent to the PTS control unit via the chassis CAN.
Changes to the parking situation after parking space detection are not considered by the parking system.
Parking guidance function sequence (with code (230) Exclusive parking assist)
If the PTS control unit recognizes that the vehicle is at a standstill, the parking space last recognized and stored is defined as the desired parking space. After reverse gear has been engaged, the PTS control unit sends the request to display the warning message via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster:
"Pay attention to all the vehicle surroundings.
Confirm with OK"
The vehicle must be driven straight back a short distance if necessary, depending on the distance of the vehicle to the parking space. This is signaled by a green lane behind the vehicle. The vehicle must be reversed until an information tone can be heard. This signals that the start position for the parking procedure has been reached and is indicated by a white bracket symbol behind the vehicle.
The PTS control unit receives the movement data from the ESP control unit via the chassis CAN.
The PTS control unit sends the display data for parking guidance via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster only when actuation of the OK button has been sent by the steering column tube module via the chassis CAN to the PTS control unit.
When the vehicle is stationary, the red actual lane (13) is displayed together with the yellow specified lane (14). The red actual lane must overlap the yellow specified lane; to do this, the steering wheel must be turned. Turning the steering wheel is read in by the steering angle sensor (N49) of the steering column tube module and transmitted to the PTS control unit via the chassis CAN. The PTS control unit changes the display of the red actual lane at the same time as the steering wheel is turned.
If the red actual lane is congruent with the yellow specified lane, the lane (15) is shown green and an information tone sounds. If the representation of the lane is located within the parking space (16), a white retaining clamp (17) with an arrow for the holding position is displayed at the end of the green lane.
The vehicle must be driven backwards up to the holding position displayed with the adjusted steering angle. When the holding position has been reached, the PTS control unit sends the request to output an information tone prompting the driver to stop the vehicle, via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster.
Once the vehicle has come to a standstill a yellow specified lane and a red actual lane are displayed again. The red actual lane must overlap the yellow specified lane; to do this, the steering wheel must be turned. Turning the steering wheel is read in by the steering angle sensor () of the steering column tube module and transmitted to the PTS control unit via the chassis CAN. The PTS control unit changes the display of the red actual lane at the same time as the steering wheel is turned.
If the red actual lane is congruent with the yellow specified lane, the green lane is shown with a white retaining clamp with an arrow for the holding position and an information tone sounds. The vehicle must be driven backwards up to the holding position displayed with the adjusted steering angle. If the holding position has been reached, the PTS control unit sends the request to output an information tone prompting the driver to stop the vehicle, and also the message "Parking guidance ended" for t = 5 s via the chassis CAN to the central gateway control unit and further via the central CAN to the instrument cluster.
Once the vehicle is stationary an acoustic warning can sound from the PARKTRONIC depending on the parking situation (e.g. with an insufficient distance to the rear obstacle). The Parking Guidance changes to maneuvering mode in which the vehicle is displayed in the parking space without lanes.
The vehicle does not always have to be parallel with the curb in the parking space at the end of the second steering angle. In small parking spaces Parking Guidance tries to guide the vehicle so that the vehicle stops as deep as possible in the parking space. The vehicle can then be positioned in the parking space by suitable maneuvering (with the aid of PARKTRONIC and parking space display).
If the system detects an obstacle when reversing on the proposed parking curve, the driver is warned; for this purpose, Parking Guidance is overlaid by a warning message.
If the Parking Guidance detects that the obstacle has been removed again the display goes back into normal mode and the Parking Guidance can be finished as usual.
If the vehicle drives over the position recognized as critical, the warning mode will end and the Parking Guidance changes again into normal mode.
| Parking system, location of components | GF54.65-P-0006-01LE | ||
| Electrical function schematic of parking system | Model 216 | PE54.65-P-2054-97CAA | |
| Parking system, block diagram | GF54.65-P-0006-02LE | ||
| Component description for electric parking brake controller unit | A13 | GF42.20-P-5000LE | |
| Component description for intelligent servo module for DIRECT SELECT | A80 With transmission 722.6 |
GF27.19-P-4020ACS | |
| With transmission 722.9 (except 722.931/950) | GF27.19-P-4020AHS | ||
| With transmission 722.931 | GF27.19-P-4020AHT | ||
| With transmission 722.950 | GF27.19-P-4020LEH | ||
| Component description for ME-SFI [ME] control unit | With engine 273 | GF07.61-P-6000MLS | |
| Component description for trailer recognition control unit | N28/1 With code (550) Trailer hitch |
GF31.19-P-4050LE | |
| Component description for ESP control unit | N47-5 Model 216.3, model 221 (except 221.095/195) |
GF42.45-P-5118LE | |
| Component description for PARKTRONIC control unit | N62 | GF54.65-P-5001LEA | |
| Component description for overhead control panel control unit | N70 | GF82.20-P-5216LE | |
| Upper control panel control unit, component description | N72/1 | GF54.21-P-6040LE | |
| EZS control unit, component description | N73 | GF80.57-P-6003LE | |
| Component description for steering column tube module | N80 | GF54.21-P-6050LE | |
| Component description for central gateway control unit | N93 | GF54.21-P-4170LE |