[beli123]

Good morning college’s. First of all i am sorry but i will write bit longer theme to explain a problem. Anyway I am stuck with one MMI 3GP from Audi A5. Car came for MMI repair, with kinda strange symptom. The point is, MMI as self functions normally without restarts, blank screen and other normal malfunction except that E380 Control Head is not operational and among that two LED from tasters from the right side of joystick are flickering or blinking. “00658-64 Control Head no Communication” dtc is present on MMI. I,ve checked cables, voltage supply, ground all possible, then also checked coding, tried with baud rate to change, nothing helps, tried another control panel, used but functional no change. As i know MMi and Panel communicate vi RS232, RX, TX, checked voltages on those pins, RX on Panel has 1,80V which for me tells that its okay but TX is constant 5V without change. is in Is there anyone that has more knowledge and experience eith MMI to help me resolve this issue, beacuse i havent had such problems in think there is HW problem and i am out of ideas ehere to look. Thanks in advance

[beli123]

Is there anyone to help?

[DukeFawks]

Use bench setup to rule out 5F or E380 issue....
E380 reset is controlled by 5F too, who knows what crappy wiring issue is going on, bad GND etc.