Quote Originally Posted by Duck's Guts View Post
Yeap, all D4's have tow assist.

Also, the 7 pin round to 7 pin flat adaptor will let the trailer lights to work.
But, no green trailer indication lights on dash during indicator operation, means that the D4 doesn't 'know' the trailer is hitched, and therefore the Trailer Assist safety function is not operational.

Wazza, your trailer probably has LED lights & therefore you need an LED shunt so that the D4's Trailer Assist function operates.
Many thanks to all for your help. Will get onto a LED shunt. Have to say owning a D4 is a steep learning curve but enjoying it very much. I also have to say this is a fantastic site - thanks for your patience.