Hi, so I am working on a 2004 Mercedes C240 4matic Sedan. I am using a Autel MD808 Pro, I was able to clear a few faults (blown fuses) via Auto Scan, but when I try to use the Control Unit feature I am receiving the message below. I am trying to clear an SRS light (bad sensor under passenger seat), but am having the hardest time. Other than these electrical gremlins, the car is great for being a 19 year old Benz).
I have updated the MD808 Pro software, troubleshooted w/e customer service said, replaced fuses related to the SRS, OBD2, and others (mainly 5 and 15 amps) along with whatever I could from research on forums. So I guess I’m hearing trying to figure it out.
TL:DR Autel MD808 Pro reads Auto Scan just fine, but I am unable to connect via Control Unit. I called Autel and they said Auto Scan works by reading the whole thing, but I need to fix the issue with the car before the device can read the control unit. Idk where to look to fix this issue.
Thanks in advance.
P.S. Ignore the red arrow and blue box, it’s not my image. I got it from the internet, but it’s my same issue.
Ello benz tech here, I’d check if the module is getting power and can , since you are having communication problems it very well the module could be off line or have damaged wiring resulting in a intermittent communication problem, had this happen on my Volvo and it drove me up the wall