Trailer Lighting Module: Description and Operation

Trailer Module (AHM):

General Block Diagram:

Functional Description:

General:

The task of the trailer module (AHM) is to monitor the light switching functions on the trailer without influencing the lamp monitoring function of the "lamp
control module" (LKM) in the vehicle.

The AHM features the following functions:
- Switching on trailer lights
- Monitoring fuses, self-test of unit
- Output of any error messages to the check-control module (CCM) The trailer module (AHM) receives the switch-on information via control lines which are connected to the rear vehicle lights.

Fuse Protection:

The lamp power circuit of the trailer is fuse-protected in the trailer module. The fuses are monitored.

An error message is sent to the check-control module in the case of defect. The message is shown in the display of the instrument cluster.

Self-Test:

The trailer module (AHM) features self-test properties, with which the operability of the module is checked (comparison of input and output information).

The defect output is set as soon as a defect occurs. The error message "trailer light" is indicated in the display of the instrument cluster.