Parking sensor problem

[moltuae]

Since you've got no fault codes, sounds to me like the bleeps are the normal 'obstruction' bleeps and that the system 'thinks' there's an obstruction because a sensor in misbehaving enough to cause a false positive but not enough to trigger a fault code.

My guess would either dirt/moisture, as Neil suggested, a partially failed/failing sensor or damp/dirty connector.

I've had to chop off and replace a couple of my front sensor plugs due to moisture and corrosion. It's possible one of yours may at the early stages of that; not enough to cause an open circuit but enough to interfere with the signal.

I'd take the bumper off and check/clean the connectors. Might be worth buying a spare sensor or two beforehand in case it turns out to be a failing sensor.