Audi S6 Stalling Issues Linked to Faulty Fuel Sensor

I had a very similar issue with my 2012 Audi S4, also with a gas engine. As someone with some automotive repair experience, I can tell you the symptoms were nearly identical, inconsistent fuel level readings and check engine warnings. The fuel level sensor fault turned out to be caused by a blown fuse in the fuel system circuit. After checking the fuel tank and level sensor connections, my mechanic found the root cause. The repair was straightforward, replacing the defective fuse restored proper function to the fuel system and sensor readings. Total cost was 52 Euro for diagnostics and fuse replacement. Before jumping to replacing the entire fuel level sensor unit, definitely have the fuses and wiring checked first. These simple issues can mimic more serious sensor failures. To provide more specific guidance about your S6: What trim level do you have? Has the fuel tank or pump been serviced recently? Are you getting any specific error codes besides the sensor fault? Does the issue occur more when the tank is at a certain fuel level?

Had my latest service at 102703 KM just last month. After troubleshooting the car sensor issue myself and finding similar symptoms in the forum, I took it to a repair shop. The fuel sensor unit was completely faulty in my case, not just a fuse problem. The car electronics showed multiple error codes related to the fuel system. The repair bill came to 480 Euro including parts and labor. They had to drop the fuel tank to replace the entire sending unit. Since the fix, my car dashboard readings are stable and the check engine light has stayed off. The stalling issue is completely resolved too. Make sure they check the complete wiring harness while the tank is down, its worth the extra inspection time to prevent future sensor issues.

Thanks for the update on your S6 repair. This actually mirrors what happened with my S4 after my initial fuse diagnosis. While the fuse replacement temporarily resolved the issue, the problems returned after a few weeks and I ultimately needed the complete fuel sensor unit replaced too. The car electronics are quite sensitive to faulty fuel level sensors, and your 480 Euro repair cost is in line with what I paid. The multiple error codes you mentioned are typical when the sensor unit fails completely, its not just the fuel gauge readings that get affected, but the entire fuel system monitoring can become unstable. One thing I learned through this: when these level sensors start acting up, its usually more cost effective to replace the whole unit rather than attempting partial repairs. Since having the complete sending unit replaced, my fuel readings have remained accurate and the engine runs perfectly at idle. For anyone reading this thread with similar symptoms, while checking fuses is a good first step, persistent fuel sensor issues combined with stalling often point to a failed sending unit that requires replacement.

The entire repair process has been educational. Initially I thought I was dealing with a minor electrical issue, but the multiple error codes and persistent stalling made it clear the fuel level sensor needed complete replacement. A faulty sensor can really create cascade effects throughout the fuel system. When the repair shop dropped the fuel tank, they were able to see the extent of the sending unit failure. The 480 Euro cost was worth it considering the car dashboard now shows accurate readings and the engine runs perfectly. No more check engine lights or stalling issues. For other S6 owners encountering similar problems, definitely have the complete fuel system diagnosed properly. While fuses and wiring should be checked first, dont waste time with partial fixes if the sensor unit itself is failing. The symptoms of erratic fuel readings combined with stalling are pretty clear indicators of a failing sensor assembly. Really appreciate all the feedback from others who dealt with similar fuel tank sensor issues. Having this knowledge helped me make informed decisions about the necessary repairs.