Convertible Top Hydraulic Control Unit: Description and Operation

GF77.37-P-3210RI Convertible Top Actuation Hydraulic Unit, Component Description
- except CODE (P99) Special model "AMG Black Series"
- refinement package
- as of model year 09

Component Identification:

Location
The hydraulic unit is located in the trunk behind the left side paneling.

Design
The RVC [UVS] hydraulic unit (A7/5) consists of the following components:
- Temperature sensor
- Relay (A7/5k1)
- Engine (A7/5m1)
- RVC [UVS] valve block (Y55/1)
- Emergency operation bolt (a)

Additionally, with code (881) Remote trunk closing (RTC [HDFS])):
- RTC [HDFS] relay (A7/5k3)
- RTC [HDFS] proportioning valve

Task
The RVC [UVS] hydraulic unit builds up a hydraulic volume flow via a hydraulic pump driven by the motor. This hydraulic volume flow is transmitted to the corresponding hydraulic cylinders via the valves integrated in the RVC [UVS] valve block or via the RTC [HDFS] proportioning valve (A7/5y3) (with code (881) Remote trunk closing (RTC [HDFS])). The functions of the Vario roof, the load assist or remote trunk closing (RTC [HDFS])) (with code (881) Remote trunk closing (RTC [HDFS])) are realized depending on the actuation of the RVC [UVS] control unit (N52).
The motor is switched on and off via the relay (A7/5k1) or the RTC [HDFS] relay (A7/5k3) (with code (881)).
The temperature of the motor is monitored by the temperature sensor (A7/5b1) to ensure thermal protection.

Load assist emergency operation
When the emergency operation bolt on the RVC [UVS] hydraulic unit is opened, the system pressure can be relieved from both hydraulic cylinders of the load assist function. When folded together, the Vario roof drops to the end position in the trunk propelled by force of gravity.