Wiring kit specifics:

•  Part number:317079300113
•  Number of pins:13-pin wiring kit
•  Wiring kit:vehicle-specific
•  Blinker monitoring:CAN
•  Coding / activation:required
•  Parking aid shut-off:yesl
•  Dauerplus (terminal 30):included
•   Charging cable:optional
•  Power connection:front

Towbar to function correctly with your vehicle requires a VW module responsible for CAN communication with your vehicle:

• Engine - when towing it works differently to cope with extra load - sometimes switches additional fan to cool
• ABS / ESP module - these work differently when trailer is hooked to avoid jack knifing. 
• CECM - This power module distributes power in another way when trailer is hooked - also visually aids the driver when trailer is hooked on dashboard 
• OPS - This is coded so when trailer is hooked up rear sensors do not beep
• CAN gateway - trailer module is coded into the gateway (main comms hub) so the car and other modules know what to do
• RVC - reversing camera - similar thing to parking sensors - recognises the trailer on the screen switches off dynamic lines
• 5F Information Electronics - ensures entertainment system displays all the trailer info correctly. 

Features:

• Westfalia-Automotive invented technology
• Vehicle specific CAN-Bus wiring
• Easy assembly
• Extremely reliable
• Complete functionality through connection to on-board electrical system
• Made in Germany