2004 honda accord lx radio problem P0685
 

I recently bought this 2004 honda accord lx, automatic transmission with 93,000 miles. The night i bought it, i found out that the radio lcd light is not working, the radio works fine and after a couple of days, the light comes on.
days later the radio itself stopped working and now it works whenever it wishes to work( coming on and off at it;s will)
I went to Auto Zone and the on board diagnostic check showed

TROUBLESHOOTING P0685
OEM BRAND: HONDA
DEFINITION
aaECM POWER CONTROL CIRCUIT MALFUNCTION
PROBABLE CAUSE
aa1: open or short circuit condition
aa2: failed ECM

Please what do I do because I an confused with this and the mechanics I have seen said I should take it to honda. sometimes the signal light makes strange noise when i turn it on when making either left or right turn and the harzard light, when turned on, takes sometime before it starts blinking.

please help me with ideas.

the factory radio has known issues. just replace with aftermarket (buy the harness and mounting kit that retains A/C controls)

thank you for the response. I have been considering this option, but today, I decided to remove the two battery terminal, check for corrosion and then fix it back. I did it and turned the car on the radio comes on and works perfect though the CD player does not work. After I turned the car off, I later turned it on and the radio won't work again. I removed the terminal and put it back and it work, but once I turn the car off and turn it on again, the radio won't work unless I remove the terminals again.

Do you think it is an electrical fault or power problem with the terminals?
Thank you for the first reply I appreciate.

just an internal problem with the factory head unit.