Kd-g322 error code query

Question

I have a 6 month old KD-G322 in-car radio/CD player. Problem is it displays normally when switched on, plays the radio channel it's set to OK, but after c.5 sec it displays "Y00.00 AY" flashing this ad infinitum. And it won't play CDs. Tried teh JVC website but no service manual for this model & no answer on their 0870 service line. Any ideas?