I have just purchased a 1.9 TDI SE Bora (54) 36K After about 15mins of normal driving the ESP warning light comes on and stays on and is only reset by switching ignition off. What should I be looking at? s it brakes?

This car has only done about 5k since last MOT and was wondering if the brakes may be a little sticky, but car drives well an no issue with the braking at all!