Audi S1 Electrical Chaos: Multiple Systems Failing

I had a very similar issue with my 2015 Audi S3. Having some experience working on Audis, these symptoms immediately made me think of control module communication problems. My car showed multiple warning lights and system failures, just like yours. The infotainment would out of nowhere reboot and various control units would lose connection. The check engine light was constantly flickering on and off. After taking it to a specialized workshop, they performed a full diagnostic scan which revealed multiple communication errors between different control modules. The root cause turned out to be a faulty cable connection to the main control unit where it connects to the vehicle BUS system. The repair cost me 155 Euro including parts and labor. Before suggesting specific fixes for your S1, could you share: Are the warning lights following any pattern? Does the issue happen more often when the engine is hot or cold? Have you noticed any correlation with wet weather? Which specific error codes are stored in the system? These details would help determine if your issue matches what I experienced or if its something else entirely. Most importantly, I recommend getting it checked soon, as these service required warnings could indicate more serious electrical issues that might affect critical vehicle systems if left unaddressed.

Thanks for the detailed rundown of your experience. My malfunction indicator lights also seem most active when the engine is warm, and they do illuminate more frequently in wet conditions. After checking my service records from the last maintenance at 163381 KM, I noticed similar communication errors were logged but apparently not addressed. The main warning light patterns involve ABS, ESC, and check engine indicators cycling on and off in sequence. The engine diagnostics show error codes related to CAN bus communication failures, particularly P0600 and U0100. Going by your experience, I will have the control module connections inspected. Hope its just a cable issue like in your case, as 155 Euro sounds much better than a full module replacement.

Thanks for the additional details. Those error codes combined with the warning light patterns you described match my experience exactly. When the CAN bus communication starts failing, it typically creates a cascade of system failures across multiple control units. Looking at my repair documentation from back then, the scan tool initially showed over 20 different fault codes across various modules. The workshop confirmed the issue by testing the voltage levels in the CAN bus network, which were unstable when the engine was warm. One warning signal that really convinced me it was a connection issue: the failures would temporarily clear after wiggling the wiring harness near the main control unit. This matches your description of sporadic errors increasing with warm engine temps and moisture. Quick tip before you take it in, have them check the ground connections too. In my case, they found slight corrosion on a ground strap that was contributing to the system failure patterns. This was included in my 155 Euro repair, but worth mentioning to the technician. With such similar symptoms and error codes, I am fairly confident you are dealing with the same root cause. Just make sure they perform a complete diagnostic scan after the repair to verify all communication errors are resolved.

The scan tool readings and your experience with similar CAN bus communication failures really help confirm my suspicions. Especially the part about the ground connections, I will definitely have those checked out when I take it in. The control module issues seem to match perfectly with the warning light patterns and error codes in my case. Given how the malfunction indicator lights behave worse with heat and moisture, a wiring problem makes the most sense. I will schedule an appointment this week to have them run a full system diagnostic scan and inspect all the connections around the main control unit. The intermittent system failures are concerning enough that I do not want to risk driving it much longer without getting it fixed. Really appreciate the detailed repair information and cost breakdown. Having a realistic idea of what to expect helps a lot. Will update once I get the results back from the workshop to confirm if the cable connection was indeed the root cause of all these electrical gremlins.