Malibu Infotainment Failure: MOST Bus Diagnostic Guide

Got some experience with this exact problem on my 2016 Chevy Impala, pretty similar setup to your Malibu. Had a really similar failure with my audio system where everything just died at once. Turned out the MOST bus network was failing because one of the control units went bad. These systems are all connected through the bus network, so when one component fails, it can take down the whole system, audio, nav, everything. My case needed the main control unit replaced, cost me about 1000 to fix including parts and labor. The workshop had to run some specific diagnostics to pinpoint which control unit was causing the bus system failure. Could you share: Any specific error codes you're getting? Did it fail suddenly or gradually? Are you seeing any intermittent behavior, or is it completely dead? This info would help confirm if you're dealing with the same issue I had with my Impala.

Thanks for sharing your Impala experience. In my case (133575 KM), the failure happened quite suddenly during normal driving. The car diagnostics showed error codes B0001 and U0184, and everything just went dark at once. The fiber optics connection seems completely dead, no flickering, no intermittent function, just total system failure. The control unit isn't responding to any reset attempts, and the audio system stayed dead even after disconnecting the battery for 30 minutes. I'll try getting it checked at the workshop this week. My recent service was just last month, and everything was working fine until yesterday. Hoping it won't be as expensive as your repair, but it's sounding pretty similar to what you experienced.

Had the exact same thing happen with my Impala last year, those error codes (B0001 and U0184) are classic signs of MOST bus failure in these models. After my post about the control unit replacement, I actually discovered something interesting during data transmission testing. The fiber optic ring in these units can break down, especially around that mileage point. Quick tip from my experience: before going for a full control unit replacement, have them check the optical ring connections first. My mechanic found that sometimes the data transmission issues can be fixed by cleaning or reseating the fiber connectors, way cheaper than replacing the whole unit. While my car diagnostics initially pointed to a complete failure, it turned out some connectors just needed attention. The audio system failure pattern you're describing matches exactly what I dealt with, the sudden complete shutdown during normal driving is particularly telling. When the car diagnostics show those specific codes together, it's almost always related to the MOST bus network architecture. In case you're wondering about cost, if it is just connector-related, you might get away with a couple hundred versus the thousand-plus I initially paid for the full unit replacement. Worth checking this first before committing to the bigger repair.

Thanks for the detailed info. Just got back from the shop and you were spot on, it was exactly what you described. The car diagnostics revealed the fiber optics connection was the culprit. The mechanic found corroded connectors in the MOST bus network that were interrupting the data transmission. Total repair cost came to €275, way better than a full control unit replacement. They cleaned and reseated all the optical connectors, and the audio system came back to life immediately. The shop also ran a full protocol test through the automotive network to make sure everything was communicating properly. Really glad I asked here before authorizing any major repairs. Could have easily ended up paying for an unnecessary control unit replacement. The whole system's working perfectly now, nav, audio, everything. Thanks for helping me avoid a much more expensive fix.