Power tilting/sliding roof (SR), function - GF77.20-P-0001CW
MODEL 204.0/2 with CODE (414) Power glass tilting/sliding roof up to Model Year 8
General information
The electric tilting/sliding roof (SR) function allows opening and closing of the SR.
Operation is by means of tilting/sliding roof switch (N70s1) in the overhead control panel control unit (N70).
The SR is a combination of sliding and tilting roof. The sliding roof function lowers the SR toward rear into the vehicle dome, the tilting function raises the rear part of the SR.
Convenience functions allow the SR to be opened and closed centrally from one control point.
The convenience functions are described separately in the convenience feature (CF) function.
The SR function includes the following partial functions:
- Manual adjustment
- Automatic adjustment
- Rain closing feature (with code (345) Rain sensor, not
)
- Position monitoring and blockage detection
- Anti-pinch protection
- Normalization
- Denormalization
- Thermal fuse
Function requirements
- Circuit 15R On
- Run-on time active (up to t = 5 min after circuit 15R Off, with front doors not yet open)
- No overvoltage or undervoltage
- SR normalized
- Anti-pinch protection functional (during closing)
- SR functional
The electronic ignition lock control unit (N73) transmits the circuit status to the interior CAN. The status of the front doors is recognized by the left front door lock (A85) or right front door lock (A85/1), read in by the left front door control unit (N69/1) or right front door control unit (N69/2) and transmitted to the interior CAN.
Function sequence for manual adjustment
Actuation of the tilting/sliding roof switch is read in to the 1st notch by the overhead control panel control unit. It then actuates the tilting/sliding roof motor (M12m1) in the tilting/sliding roof drive unit (M12) in the desired actuation direction for the time the request is present. The anti-pinch protection is activated during closing.
When denormalized, it is only possible to move the SR in increments of t = 0.5 s.
Function sequence for automatic adjustment
When the tilting/sliding roof switch is actuated momentarily beyond the 1st notch, the SR is moved automatically in the actuation direction up to the end position. Automatic adjustment is interrupted when the tilting/sliding roof switch is actuated again. The anti-pinch protection is activated during closing.
Recognizing switch signals:
Unambiguous actuation is recognized after uninterrupted actuation of the tilting/sliding roof switch for t = 40 ms ± 10 ms. The maximum actuation time is t ≥ 20 s.
After t ≥ 60 s, a "hanging" tilting/sliding roof switch is recognized. The tilting/sliding roof switch is capable of actuating a function again only after the rest position is recognized.
Rain closing
Additional function requirements
- Circuit 15R off or vehicle locked
- SR open in sliding position
Function sequence for rain closing
Rain closing is actuated as follows:
- Moistening of windshield is recognized by rain/light sensor (B38/2)
- Run-on time has expired (t = 6 h)
- The voltage range (U = 10 V to 15 V) or temperature range (T = 5° C to 85° C) of the rain/light sensor is exceeded.
The front SAM control unit with fuse and relay module (N10/1) transmits the request to the overhead control panel control unit via interior CAN. It actuates the tilting/sliding roof motor. The SR is moved to the tilt position. Monitoring is then no longer performed.
During rain closing, an alarm actuation is suppressed by the interior protection (with code (882) Interior monitoring (with ATA only) to prevent unintentional actuation of the anti-theft alarm system (ATA).
Function sequence for anti-pinch protection
The anti-pinch protection is based on the comparison of the current power consumption for the tilting/sliding roof motor with the power consumption determined during a learn-in procedure or adaptation.
If this comparison exceeds a certain limit value during closing, this is recognized as pinching by the overhead control panel control unit.
Learn-in procedure:
The SR is moved through all closing procedures in the normalized state. The overhead control panel control unit adapts to a modified power consumption of the tilting/sliding roof motor resulting from increased sluggishness (e.g. from dirt in mechanism).
Special case manual closing:
If the tilting/sliding roof switch is reactuated in the closing direction within t = 2 s after reversing, a higher force is allowed. The anti-pinch protection is deactivated after the next attempt.
Function sequence for position monitoring and blockage detection
Position monitoring is performed by the overhead control panel control unit by evaluating the signals from Hall sensor 1, tilting/sliding roof (M12b1) and Hall sensor 2, tilting/sliding roof (M12b2), located offset 90° on the shaft of the tilting/sliding roof motor.
The position of the SR is determined and monitored by counting the Hall sensor pulses.
The zero position is located in the SR position in the open tilt
The SR is only stopped when pinching is recognized during opening.
During closing, the SR is stopped and then reversed (moved in opposite direction).
position. The zero position is set by synchronization.
A lock-up is recognized if no signals are recognized by the Hall sensors for a time of t = 350 ms.
Actuation of the tilting/sliding roof motor is interrupted after a lockup.
Normalization function sequence
Manually open SR with tilting/sliding roof switch to tilt position and rear tilting roof position until the mechanical stop is reached and continue to actuate the tilting/sliding roof switch.
The signal must be present for a minimum of t = 1 s, so that the overhead control panel control unit recognizes lock-up of the tilting/sliding roof motor and can set the location counter to zero.
In the normalized state, the tilting/sliding roof motor is switched off by the overhead control panel control unit during automatic opening and closing before the mechanical stop is reached.
Function sequence for denormalization
Denormalization takes place:
- with circuit 30 Off during actuation of the tilting/sliding roof motor
- if the SR exceeds the defined motion range.
- if one of the two Hall sensors fails for 40 signal edges
- if both Hall sensor signals fail for longer than t = 320 ms during reversing
- if voltage is too low and the SR is actuated
The position of the SR cannot be defined in the denormalized state. The function is then limited to manual closing and opening.
Function sequence for thermal protection
A thermal protection switch integrated into the tilting/sliding roof motor protects the tilting/sliding roof motor against overload. The tilting/sliding roof motor is not designed for continuous operation.
If the maximum permissible operating time is exceeded, the tilting/sliding roof motor is switched off.
If the thermal protection function is tripped, actuation is inhibited for a minimum cooling time. During the reversing operation after pinch recognition, the thermal protection function is not active.
| Electrical function diagram for tilting/sliding roof (SR) | PE77.20-P-2050-99FAA | ||
| Electric tilting/sliding roof (SR), location of components | GF77.20-P-0001-01CW | ||
| Electric tilting/sliding roof (SR), block diagram | GF77.20-P-0001-03CW | ||
| Door lock, component description | A85, A85/1 | GF80.20-P-4124CW | |
| Rain/light sensor, component description | B38/2 With code (345) Rain sensor |
GF54.21-P-6000CW | |
| Tilting/sliding roof drive unit, component description | M12 | GF77.20-P-5212CW | |
| Front SAM control unit with fuse and relay module, component description | N10/1 | GF54.21-P-6070CW | |
| Left front door control unit, component description | N69/1 | GF72.29-P-6001CW | |
| Right front door control unit, component description | N69/2 | GF72.29-P-6009CW | |
| Overhead control panel control unit, component description | N70 | GF82.20-P-5216CW | |
| Electronic ignition lock control unit, component description | N73 | GF80.57-P-6001CW |