Electrical Components; Convertible Top Module - BMW 3-series convertible Complete Vehicle Workbook

Electrical Components

Convertible Top Module

The Convertible top module (CTM) is the central electronic control
module for all functions of the retractable hardtop. The installation
location of the CTM is the right divider compartment module.
The CTM controls the retractable hardtop, the rear module and the
Soft Close Automatic feature. Power is supplied to the CTM by the
junction box with terminal 30g.
There is an additional power supply to the CTM via terminal 15 of
the Car Access System (CAS) so that in certain cases of
malfunction, such as an interrupted supply from the junction box,
adequate diagnostics and communication with the diagnostic
tester are possible.
The CTM controls the electric motor for the interlocking of the roof
shells and of the front roof shell to the cowl panel. In addition, it
controls the hydraulic pump and the 8 hydraulic cylinders via the
5 valves in the hydraulic unit.
During the hardtop and rear module movements, the respective
position is detected by 9 Hall sensors and 5 microswitches in the
cowl panel, hardtop and rear module and forwarded to the CTM via
the respective wiring harness. Each of them signals whether a cer-
tain status has been reached and whether the CTM can initiate the
next phase.
The current supply of the microswitches/Hall sensors is provided
by the CTM. The CTM also reads in the status of the button.
The CTM is connected to other control units via the K-CAN.
For example, information about the outside temperature, driving
speed and status of the boot lid is received via K-CAN.
When the hardtop is opened or closed, the CTM sends the request
to lower the side windows to the FRM.
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E93 Complete Vehicle Workbook
In certain critical situations, the
CTM triggers introductions that
are easily understandable to the
customer in the instrument cluster
as check control messages and
text messages in the CID.
Depending on whether the roof is
closed or open, the CTM will
transmit a signal to the diversity
aerials to switch from glass
mounted aerials to the auxiliary
(bumper/trim mounted) aerials.
Index
1
2
41-pin connector for power supply, SCA, button, Hall sensors, micro
3
4
Explanation
26-pin connector for Hall sensors and micro switches
2-pin connector for electric motor
switches and K-CAN
18 pin connector for hydraulic control unit