Trailer Module (AHM) And Trailer Coupling Release: Notes

This functional description describes the trailer module (AHM) for the following vehicles:

• E81, E87, E90, E91, E92, E93  (BMW 1-Series, 3-Series)
• E60, E61, E63, E64  (BMW 5 Series, 6 Series)
• E65, E66, E67, E68  (BMW 7 Series)
• E70  (BMW X5)
• R55, R56, R60, R61  (MINI)

The following are also described:

• The control unit for the trailer tow hitch release in the E9x with the associated electrical folding  trailer tow hitch and
• the control unit for the trailer coupling release in the E6x and E70 with the associated fully automatic  trailer tow hitch

This equipment range with the SA3AC "trailer tow hitch with electrical articulated ball head" is installed in these vehicles.

The trailer module (AHM) is an auxiliary control unit for the footwell module (E8x, E9x, E7x, R5x  ) or light module (E6x  ). At the moment, two different trailer modules (AHM) are installed. The AHM3  is the version that was deployed up to 09/2006. The AHM3+  is the revised version. Essentially, it differs from the AHM3  with regard to the following characteristics:

• 2 lines and fuses for the power supply, enabling more electrical power output to be provided for the trailer lighting.

The trailer module (AHM) separates the load circuits of the trailer from the circuits of the towing vehicle. The control unit also reports the status of the articulated ball head to the trailer module (AHM) for the trailer coupling release. These states are: Trailer tow hitch locked or not locked.

The AHM3+  will be fitted as volume production launch on the E70  and R55  . In all other series mentioned above, the AHM3+  will be installed from 09/06. Please note the following differences in the installation and function of the trailer module (AHM) and the trailer tow hitch:

• MINI:  The trailer module (AHM) is installed as an optional accessory in version R56  . The trailer module (AHM) delivers the electrical energy for the rear bicycle carrier offered as an optional accessory. No trailer tow hitch is offered for the R56  . For Series R55, R60  and R61  , a removable trailer tow hitch is installed.
• BMW:  The trailer module (AHM) is installed if the vehicle is equipped with a trailer tow hitch. The trailer tow hitch can be firmly installed or removable. Moreover, it is also possible to fit a semi-electric or fully electrical articulated ball head.