Control Module
The trailer module manages the electrical connection between the vehicle and the trailer.
The control module is located in the cargo compartment, behind the right wheel arch.
The trailer module communicates with directly connected components and with other control modules via the controller area network.
The control module checks the input and output signals through an integrated diagnostic system. A diagnostic trouble code is stored if the control module detects a fault. Any diagnostic trouble codes are stored in the control module memory. The data can be read off using VIDA (Volvo scan tool).
An easy way to check if the control module has power and is grounded, is to switch on the ignition and the turn signal lamps when the tow hitch connector is connected to its socket. The driver information module indicator lamp lights and the trailer turn signal lamps should flash as they do on the vehicle. The trailer's connectors, cable harness and lights must not be damaged or defective when this check is carried out.
For further information, see SIGNALS .