I had this problem and had to take it to a Suzuki dealership in the end, it was the sensor boost 18590-32G00 that was faulty.
I searched ebay and couldn't find a second hand one for my model and fowlers didn't have stock, so had to bite the bullet and pay £251 for sensor + labour, but after watching them change it, I could of done it myself.
The mechanic told me that C17 is the front sensor (blue cover on wire) and C13 is the back sensor, if you swap them round the fault moved. He also said sometimes the vacuum pipe can cause the problem and is worth checking before replacing the sensor.
My bike is a 2016 Veek, hope this helps.