Body - Convertible Top Will Not Open/Close Completely
SI B54 17 06Special Roofs
June 2011
Technical Service
This Service Information bulletin supersedes SI B54 17 06 dated November 2006.
[NEW] designates changes to this revision
SUBJECT
Convertible Top Does Not Completely Open or Close
MODEL
E64 (6 Series Convertible)
SITUATION
The customer may notice that the convertible top will either not completely open or close. The convertible top appears to be completely open or closed, yet the red top operation light continues to flash and the "top not locked" message appears.
Fault code A6A4 (overspeed) will typically be stored in the CVM (Convertible Top Module) when this situation occurs.
CAUSE
The angle of rotation sensor (Control Element) on the tensioning bar is defective or reading the wrong segment.
The sensor position segments are very close together, and if the frame or the sensor itself is slightly out of position, the wrong segment may be read.
This condition is exaggerated by temperature-induced expansion when the vehicle sits in direct sun light for an extended period of time.
CORRECTION
Replace and/or modify the angle of rotation sensor as applicable.
PROCEDURE
Refer to the attachment and the recommendations below.
^ Attempt to reproduce the customers issue. This may require allowing the vehicle to sit in the sun to promote some degree of temperature-induced expansion.
^ [new] Compare the convertible top segment status using ISTA test plan B5410_64DWG to the known correct segments shown in the attachment. The test plan now includes the raw values of the main and fin sensors to help simplify the adjustment of the sensors.
^ If the angle of rotation sensor (Control Element) on the tensioning bar is reading the wrong segment at any position of the convertible top, proceed with procedure A and/or B, as applicable.
A. Vehicles produced up to 8/2005
^ First check the angle of rotation sensor (Control Element) part for the proper (minimum) date code. The part number has not changed and the updated part can be identified by it having a date code of August 1, 2005 or newer, shown as 1.8.05 (dd.mm.yy).Replace the angle of the rotation sensor (Control Element) with the updated part, if required.
Note:
If a vehicle produced up to 8/2005 already has the updated part (by date code), proceed to procedure "B".
^ Adjust the sensor to match the segments in the attachment, and then allow the car to sit in the sun for a few hours with the top closed. Retest the top operation for correct operation.
^ If the same condition returns, follow procedure B.
B. Vehicles produced from 8/2005 and vehicles produced up to 8/2005 with the new style sensor (Control Element) installed.
^ The existing sensor must be removed from the convertible top frame and modified.
^ After removing the sensor from the frame, elongate the two upper attachment holes on the sensor cover as shown by the arrows.
^ Each of these 2 holes should be elongated in the indicated direction by approximately 2-3mm, using a small hand file.
^ Install the sensor back onto the convertible top frame.
^ Rotate the sensor clockwise around the lower, unmodified hole.
^ Secure the bracket to the frame.
^ Check the convertible top position status and, if possible, allow the car to sit in the sun to further validate the effectiveness of the modification.
^ [NEW] If the sensor continues to read an incorrect segment, it may need to be adjusted one or more times until it reads correctly all the time. The raw values will show you if the sensor adjustment is too close to the next segment reading. In some cases, the sensor will need to be filed in the opposite direction to allow counterclockwise rotation.
PARTS INFORMATION
[NEW] WARRANTY INFORMATION
ATTACHMENTS
Procedure