Audi A4 Power Surge Issues Causing System Failures

I had a very similar electrical issue with my 2015 Audi A6 last winter, and as someone with moderate experience working on cars, I understand your concern about potential system damage. The symptoms matched exactly what youre describing, multiple electrical issues, voltage fluctuations, and starting problems. Initially thought it was just the voltage regulator, but after proper diagnosis, it turned out the battery was heavily discharged and damaged, causing a cascade of electrical system problems. Had it checked at a workshop where they performed a complete electrical system diagnostic. The testing revealed the battery was not just discharged but had some defective cells, which caused irregular power delivery and high voltage spikes throughout the systems. The total repair came to 290 Euro, including the new battery and diagnostic work. To help assess your situation better, could you share: Current battery age and type, Whether youve noticed any warning lights before the issues started, If the problems occur more frequently when its cold, Whether youve had any recent electrical accessories installed These electrical issues can cascade quickly and potentially damage other car electronics, so its best to have it checked soon. The voltage fluctuations you mentioned could indicate similar battery problems or might point to alternator issues.

Thanks for the details on your experience. My last service was at 165000 KM where they did a routine maintenance check. The car ECU keeps throwing multiple error codes related to voltage spikes. Had the car battery tested and its showing 12.2V when idle, jumping to 15.1V while running, which seems way too high. The voltage regulator in the alternator is my prime suspect since these readings point to poor voltage control. I noticed the headlights flickering slightly before these issues started, especially at lower RPMs. No aftermarket electronics installed, running all stock components. Systems out of nowhere shutting down mid-drive is getting concerning, particularly when it affects critical electronics. Would be interested in knowing if replacing your battery solved all the overvoltage warnings or if additional repairs were needed?

Based on your readings of 15.1V while running, I can confirm you are dealing with a more serious alternator issue rather than just a battery problem like in my case. When I had my A6 repaired, replacing just the battery didnt solve the overvoltage warnings, the electrical issues persisted until the voltage regulator in the alternator was replaced. The circuit protection system keeps logging these faults because 15.1V is well above the normal charging range of 13.8-14.4V. This excessive voltage explains your unusual system failures, as modern car electronics are sensitive to power fluctuations. In my situation, the total fix ended up requiring: New alternator with integrated voltage regulator (480 Euro), Battery replacement due to damage from voltage spikes (210 Euro), System diagnostic reset (120 Euro) The flickering headlights at low RPMs is a classic symptom of a failing voltage regulator. Would strongly suggest getting this addressed soon, as continued overvoltage conditions can damage expensive control modules and other electrical components. The battery readings you shared indicate its already being stressed by the improper charging voltage. When I finally got mine fixed, all the electrical issues disappeared completely. No more unusual system shutdowns or fault codes related to electrical malfunctions.

The voltage readings and detailed repair breakdown you shared align perfectly with what Im experiencing. Your comment about headlight flickering being tied to voltage regulator failure makes a lot of sense given my symptoms. My high voltage issues seem to match the alternator failure pattern you described. The car electronics going haywire definitely has me worried about potential damage to other components. Im going to schedule a repair before any expensive control modules get fried by these constant voltage spikes. Quick question on your repair, after they replaced both the alternator and battery, did they need to do any special reprogramming or just a basic car ECU reset? Also wondering how long the complete repair took since I need to plan for alternate transportation. The fact that your electrical issue was completely resolved after the fix is encouraging. These unusual system failures while driving have been pretty stressful, so Im looking forward to getting this sorted. Thanks for sharing such detailed info about your experience, its been really helpful in understanding whats likely going on with my car.