Design, Function of Electrical Components
Design, function of electrical components
A Control unit for top actuation (N52)
The top control unit located under the right side of the baggage shelf or right occasional seat controls the following functions:
- Opening and closing the top (including lowering side windows and roll bar) after actuation of the top switch
- Locking and unlocking the coupe roof after actuating the top switch. Automatic switchover to coupe roof/top operation after attaching or removing the coupe roof
- Monitoring of safety-relevant information (speedometer function, speed signals, roll bar control unit, function of operating switches, locked state for top locks)
- Convenience operation (moving up/down) for roll bar after actuating roll bar switch.
- Lowering/raising side windows after actuating window lift switch
- Momentary contact function for automatically lowering the side windows after corresponding actuation of window lift switch
- Convenience closing of side windows via lock on driver's door
- Convenience operation for side windows (operation with door open, in spite of ignition being switched off).
- Diagnostic system with pulse display for malfunction recognition.
B Control unit for roll bar (N53)
The roll bar control unit located below the baggage shelf (center), is responsible for "crash actuation"; the top control unit for "convenience actuation" of the roll bar. Both control units are connected with one another via 2 lines. The following information is transferred to the top control unit
- Roll bar control unit okay
- Roll bar control unit defective
- Acceleration (of vehicle) greater than 0.4 g
- Crash actuation
C Limit switches directly related to top
The total opening/closing function for the top consists of 3 subfunctions:
- Open top (deposit in top compartment) or close top (move toward windshield frame)
- Open/close cloth holding brace
- Open/close top compartment cover
Each of these subfunctions have 3 positions signalled by limit switches:
- "Open", i.e. completely opened
- "Closed", i.e. locking pins inserted into locks. The locking operation can start.
- "Locked", i.e. the associated lock is locked mechanically.
The following limit switches are required for these subfunctions:
- Cloth holding brace open/closed/locked
- Top compartment cover open/closed/locked
- Top open/locked
A limit switch for "top closed" is not required because the front locks are designed differently than the center and rear locks.
The "top up" limit switch is a special feature. After reaching this limit switch the hydraulic cylinders for the top drive are switched over to differential operation (e.g. pressure in cylinder is reduced by approx. 50 %) during the operation "close top".
D Limit switch, roll bar down (S83/1)
This limit switch indicates when the roll bar is completely down and is required for:
- Top operation blocked because top would collide with roll bar when up
- when roll bar sensor is defective. Warning light in roll bar switch flashes as long as limit switch is switched on.
- After crash actuation a special program is activated in the top control unit. This special function is cancelled when the limit switch has switched (again).
E Limit switches, side windows down (S21/8, S21/9)
These limit switches indicate when the side windows are all the way down and are required for:
- Top operation blocked, because top would collide with side windows when up
- Momentary contact function for stopping function
F Top actuation switch (S84)
The top actuation switch represents a small top. Pushing the switch toward the front means: close top or lock coupe roof
Pushing switch toward rear means: open top or remove coupe roof.
A function control light in the top actuation switch illuminates as soon as the top is actuated and extinguishes only when all of the locks are locked properly.
G Roll bar actuation switch (S83)
The roll bar can be moved up and down with the roll bar actuation switch. After crash actuation the roll bar can be moved down with the control switch. To do this the control switch must first be pressed in the direction "up" (approx.6 - 10 s), until a soft click is heard. Then the roll bar can be moved down by actuating the switch.
H Window lift switches (S21/1, S21/2)
The window lift switches have 2 different functions: rolling the side window up and down as previously. Completely lowering the side windows by overpressing the switch while lowering.
J Window lift motors (M10/3, M10/4)
The window lift motors are controlled via the top control unit.
K Speed signals
The top control unit requires input signals to establish whether the vehicle is standing still. For safety reasons 2 speed signals are input: electric speedometer, wheel speed sensor front left.
L Acoustic warning (E15h1)
A high frequency gong sounds when the vehicle is driven without the top/coupe roof being locked properly. This gong is located in the dome light.