I have a Sony radio that when put at more than 20% of its volume capacity will reset itself (turn off) and turn itself back on and will continue to do this until the volume is lowered and the headunit is reset.
usual cause of it is your over taxing the radio. the radio is working so hard to push your speakers it's ether heating up or clipping the signal so bad to your speakers it shuts off to prevent damage. most of sonys car audio products = crap. so if your driving large speakers thats why, or you have a bad ground to the radio.