..
5
Hydraulic Unit ....................................................................................
6
Hydraulic Cylinders ............................................................................
7
Hydraulic Solenoids ...........................................................................
9
Storage Cover Motor .........................................................................
10
Windshield Frame Lock Assembly .....................................................
11
Top Switch ........................................................................................
12
Hall Sensors ......................................................................................
13
Angle Hall Sensors ............................................................................
19
Compartment Floor Micro Switch ......................................................
20
I P O
......................................................................................... 22
System Operation ...................................................................................
23
Emergency Operation .............................................................................
28
Comfort Operation ..................................................................................
29
Diagnosis
.........................................................................................
30
Hard Top
.........................................................................................
33
Workshop Hints ......................................................................................
35
Table of Contents
CVM AND CONVERTIBLE TOP 2
CVM and Convertible Top
CVM AND CONVERTIBLE TOP
Model: E46 Convertible
Production Date: 01/00
Objectives:
After completing this module, you should be able to: Describe the lowering and raising sequence of the Convertible soft top in details. Name all the sensors and their functions that are used to open or close the soft top. Identify and describe electro-hydraulic components used in the Convertible top. Describe the information that is exchanged between the CVM II and the GM V. Describe the operation of the Storage Compartment Cover Lock Motor. Identify all the hall sensors, angle hall sensors and micro-switches used in the soft top. Explain all of the pre-conditions for Convertible soft top operation. Describe the wiring of the Hard Top Locks on the left and right. Diagnosis a Faulted CVM System. Describe the locking / unlocking procedure for the manual soft top. 3
CVM and Convertible Top
INTRODUCTION
Purpose of the System:
The E46 Convertible-top is a fully automatic electro-hydraulic system that completely opens
and closes the soft-top using hydraulic cylinders and electric motors. It consist of the con-
vertible module (CVM II) which controls and monitors the complete operation of the system.
The CVM II interacts with the General Module which controls the operation the convertible-
top storage compartment cover and window operation when lowering or raising the soft-
top.
Convertible top features:
Electro-hydraulic operation.
Comfort opening using FZV key or door lock cylinder.
Comfort closing using only the door lock cylinder (No anti-trap protection).
Glass window
Top operation monitored using hall sensors and hall angle sensors.
Convertible Top
Module
Hydraulic Unit
w/ Solenoids
Storage Cover Unlock Motor
Top and Frame
Solenoid Valve
Block
General Module
Top Switch
ART-E46ICBODY 4
CVM and Convertible Top
Components of the System:
Top and Frame
The top frame is similar to the E36iC with modifications for the adoption of the hydraulic
cylinders used for raising/lowering the top. The unlock motor and gear drive assemblies are
attached to the front of the top frame as on the E36iC.
The convertible top consists of three layers: The outer layer is fabric with a non-replaceable glass rear window. A middle fleece liner is installed between the fabric and inner liner for sound and
weather insulating purposes. The inner liner is similar to the E36iC and is attached to the top frame so that it
stretches tight when the top is closed.
OUTER FABRIC
INNER LINER
FLEECE LINER
ART-TOPLAYERS 5
CVM and Convertible Top
Convertible-Top Module (CVM II)
The convertible-top module (CVM II) is installed in the left rear quarter panel behind the inte-
rior trim panel. It contains the processing, controlling and monitoring electronics for the
complete top operation. The CVM II communicates with the GM over the K-Bus for opera-
tion of the top storage cover and windows.
Operation of the hydraulic cylinders is controlled via final stages and solenoids mounted on
the hydraulic unit and top frame.
The CVM is fully diagnoseable and contains a fault memory for storage of monitored faults.
Diagnosis is carried out over the K-Bus with the DIS or MoDiC.
CVM II
61E46CVM0300
61E46CVM0400
CVM II 6
CVM and Convertible Top
Hydraulic Unit
The hydraulic unit is mounted in the trunk on the left side behind the trim cover. It is mount-
ed on a rubber bushing and covered by sound insulation for noise reduction during pump
operation. The hydraulic unit consists of:
Motor,
Pump,
Storage Cover Solenoid Valve/ Drain Solenoid Valve
Reservoir.
Temperature Sensor - hydraulic fluid
The hydraulic unit provides an operating pressure of up to 200 bar for the tops operation.
A temperature sensor on the hydraulic unit will signal the top module to cease operation if
the fluid temperature exceeds 95
0
C. Any function started will be completed before the sys-
tem is switched off. If the temperature exceeds 105
0
C, the system is immediately switched
off and the emergency closing procedure will be required for closing the top.
When the temperature drops below 95
0
, the operation of the top can be resumed.
Filling or checking the hydraulic fluid is only carried out when the top is lowered in the stor-
age compartment. The recommended fluid is ARAL VITAMOL PN 54 34 8 410 000 (Refer
to the repair manual for filling procedures)
54HYDRAULICPUMPE46050 7
CVM and Convertible Top
Hydraulic Cylinders
Top Storage Compartment Cover
Two hydraulic cylinders are positioned on the left and right sides in the trunk for opening
and closing the top storage compartment cover. A Hall sensor is positioned on the left
cylinder to detect the full opened position of the cover.
Cylinder Removed
Cylinder Installed
Tensioning Bow (Clamping Bracket)
Two hydraulic cylinders are positioned on the left and right sides of the tensioning bow, on
the top frame linkage for raising and lowering the bow. An angle hall sensor is installed on
the left tensioning bow linkage to detect the positioning of the bow. The hydraulic lines for
the right side tensioning bow cylinder are routed under the top fabric along the tensioning
bow.
Hall Sensor
54E46CYLINDER1200
54E46CYLINDER1300
54E46CYLINDER0900
ART-KT5355 8
CVM and Convertible Top
Main Pillar
Two hydraulic cylinders are positioned on the left and right sides of the top frame linkage
for raising and lowering the soft top frame. An angle hall sensor is used to detect the posi-
tioning of the main top linkage. The hydraulic lines for the right side main pillar cylinder are
routed under the top fabric along the tension bow.
Two gas filled piston struts are mounted on the top frame linkage, next to the hydraulic
cylinders, to dampen the raising and lowering of the top frame.
Gas Strut
54E46MAINPILLAR1000
54E46MAINPILLAR1100
54E46GASSTRUT0800 9
CVM and Convertible Top
Hydraulic Solenoids
Two hydraulic solenoids are mounted on the hydraulic
unit:
One solenoid valve (V1: I01043 convertible top
cover) controls the opening and closing of the
storage compartment cover The second solenoid valve (V5: I01061, pressure
deactivation) is the drain solenoid for relieving
pressure in the hydraulic cylinders when the key is
switched off. The drain solenoid also holds system
pressure when the top switch is released during
operation.
Three hydraulic solenoids are mounted on the valve
block on the left side of the top frame. Solenoid valve (V2: I01027, extend main pillar)
controls the operation of the main pillar hydraulic
cylinder.

Solenoid valve (V3: I01028, extend tensioning bow)
controls the tension bow hydraulic cylinders for
lowering. Solenoid valve (V4: I01029, retract tensioning bow)
controls the tension bow hydraulic cylinders for
raising.
54E46HYDRAULICCONNECTOR0600
ARTSOLBLOCK 10
CVM and Convertible Top
Top Storage Compartment Cover Lock Motor
The top storage compartment cover lock motor is located on the drive shaft tunnel under
the rear seat. It consists of the motor with a hall sensor (S700), gear linkage assembly and
two bowden cables. Two locks are located on the right and left sides for locking the stor-
age compartment cover. The lock motor hall sensor (S700) detects the locked/unlocked
position of the storage cover.
During the soft top operation, when the tensioning bow is raised or when the top is in the
storage compartment, the CVM signals the GM over the K-Bus to unlock the storage com-
partment cover. The GM activates the lock motor and the motor turns 180 degrees to
unlock the cover latches. The motor always turns in the same direction to unlock/lock the
cover.
Once the motor has turned 180 degrees, the hall sensor (S700) input signal will cause the
GM to switch off the motor. At the same time, the GM will