My car stereo suddenly stopped working and a message appear on it's screen CANCHECK , went to someone to fix it and they made a new software and it starts working however the steering wheel control did not work and the relation between ignition start/stop with car audio start/stop didnot work too, the dealer couldn't fix this issue again so i decide to remove the new software and refunded back my money and the car audio returned to show the same error CANCHECK. I've tried another audio from another car however same message shown on the radio screen. Have checked the car on computer failure system it shows error code C1705 related to radio.
Do you have any idea how to fix the car audio noting that I unplugged the negative pole in car battery for half an hour but still not worked up.