Protection against mechanical damage
To protect the mechanism against mechanical damage due
to faulty operation, there are two safeguards:
1. Automatic lowering.
2. Slipping clutch.
If pressure is applied to the display from above and F330 is
operated, the display is lowered at a steady speed. If the
pressure applied to the display from above exceeds a
defined value, a slipping clutch decouples the drive motor
from the lifting arm in an effort to protect the drive against
mechanical damage.
If the Hall-effect sensor fails but the limit switches are
intact, the display extends and retracts according to a fixed
characteristic. The characteristic is initiated by an 80%
PWM signal.
If one of the limit switches fails, the display also moves to
the stop according to a fixed characteristic (80% PWM).
The motor then stops if motor operation is not detected for
a set period of time based on the Hall-effect sensor signal.
Service position
The display mechanism has a service position. The display
must be moved into this position to remove it from the
mechanism. The service position can be activated using the
Scan Tool.
This ensures the following:
•
The display is not placed under stress.
•
The connecting plug on the display can be accessed.
Diagnostics
The display mechanism and Display Unit Button E506 are
diagnosed under Vehicle Electronics Control Module 1 J794
using Address Word 5F.
52
Display Unit Button
E506
637_073