take a look at the make and let us know, the Bridgestones are the manufacturer recommended tyre for the zed and they are truly awful and can cause these kind of issues, if its below even Bridgestones standard then maybe worth changing them.
When i used to join the m23 from the m25 there is a massive corner that joins it and on Bridgestones in the dry or wet the TCS used to kick in all the time and I was barely going 55 round it, on Michelins its about as planted as you can get, surprising with the zed what tyres work with it and what dont very well.