Tow Hitch (Optional Extra)

Fig 1: Identifying Trailer Module (TRM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The trailer module (TRM) manages the electrical connection between the vehicle and the trailer. The trailer module (TRM) is directly connected to the rear electronic module (REM).

The primary task of the trailer module (TRM) is to manage output signals to the tow hitch cable harness for:

• Turn signal lamps
• Brake light
• Parking lamps
• Fog lamps.

The rear electronic module (REM) transmits the following voltages to the electrical socket for the tow hitch:

• Back-up lamp
• +12V voltage
• +12V supply.