SQ5 Alternator Failure Symptoms and Fix Guide

As a weekend mechanic with some experience working on Audi vehicles, I had a very similar issue with my 2014 S5 last winter. The symptoms you describe match exactly what I experienced, the charging system problems started with dim lights and eventually led to the car not starting reliably. My car showed the same warning lights and electrical gremlins. After the alternator issue was confirmed, I had it fixed at an independent workshop specializing in European vehicles. The total repair cost was 960 Euro, which included the new alternator, serpentine belt replacement, and labor. The main symptoms that point to a failing alternator in these engines are: Battery low warnings, Flickering lights, Car won't start consistently, Multiple electrical system warnings, Reduced power (as the car tries to minimize electrical load) Before committing to the repair, could you share: Current mileage on your SQ5? Are you getting any specific error codes? Have you had the battery tested recently? Does the serpentine belt look worn? This would help confirm if your situation matches what I experienced and ensure youre getting the right fix for your charging system problems.

Thanks for the helpful information. My current mileage is 171762 KM and I had my last service 3 months ago. The alternator issue seems to be getting worse, especially in the last week. When I measured the battery voltage it showed only 11.2V while running, which definitely indicates an alternator problem rather than just a battery low condition. I got P0562 and P0563 error codes during the engine misfire episodes, both related to system voltage. The serpentine belt looks okay visually but makes a slight squealing noise on cold starts. The battery is fairly new, replaced it 6 months ago before these issues started. I will likely proceed with the alternator replacement based on all these symptoms matching up. The starter motor still works fine when the battery is charged, but it struggles more each day. Will update once I get it fixed.

Thanks for the voltage readings, 11.2V while running is definitely confirming our suspicion of alternator failure. Those P0562/P0563 codes are classic indicators of charging system problems that I also saw before replacing mine. The engine misfire episodes you mention are a typical consequence when the car electronics dont get enough power. In my case, the misfires completely disappeared after the alternator replacement. Like your case, my serpentine belt also made that characteristic squealing noise before failing completely. Even though it looked fine visually, the workshop found it had glazed spots causing poor contact with the alternator pulley. Getting both the alternator and belt replaced together was the right call. Since youve got a relatively new battery, it should bounce back once the charging system is fixed. Just make sure to get a full charge on it after the repair, mine needed about 30 minutes of highway driving to fully recover. The rapid progression of symptoms matches my experience too. Within about 2 weeks of first noticing the alternator issue, my car became nearly undriveable. Better to get it fixed soon before being stranded somewhere. Would be interested to hear how the repair goes and if it resolves all the electrical gremlins like it did in my case.

The voltage readings and error codes you shared definitely confirm what I suspected. A voltage drop to 11.2V while running instead of the normal 14V range is a clear sign of alternator failure, and those specific trouble codes directly point to charging system problems. With my mileage at 171762 KM and similar symptoms, I feel confident proceeding with the alternator replacement. The squealing noise from the serpentine belt during cold starts, despite looking okay visually, is another typical indicator that matches others experiences. Its reassuring to hear that replacing both the alternator and belt resolved similar issues in your case. Since my battery is only 6 months old, it should work properly once the charging system is fixed. Im planning to schedule the repair this week before the car becomes completely undriveable. The symptoms are definitely getting worse quickly, the car electronics seem more unstable each day, and Im worried about being stranded if I wait too long. Will post an update after the repair to let everyone know if it fixed all the electrical issues. Thanks for sharing your experience, it helped confirm my diagnosis and gave me a good idea of what to expect for the repair.