RS6 Starting Failure Points to Fuel System Issues

I experienced a similar starting issue with my 2014 Audi RS7 4.0L. The symptoms matched exactly, intermittent starting problems with brief engine fault light illumination during start attempts. After multiple diagnostic attempts, the root cause was actually corroded battery cable connections, not a fuel injection or ECU issue as initially suspected. The corrosion created resistance in the circuit, causing voltage drops that triggered various electronic fault signals. This is a serious issue because poor electrical connections can mimic multiple problems, leading to misdiagnosis. The voltage irregularities can affect the fuel injection system and throw check engine codes that seem unrelated to the actual problem. Key diagnostic steps that revealed the true issue: Voltage drop testing across battery connections, Check engine code scanning during start attempts, Testing ECU ground connections, Measuring starter motor current draw The fix involved: Cleaning all battery terminal connections, Replacing corroded cable ends, Applying dielectric grease, Checking/cleaning all major ground points After addressing the electrical connections, all starting issues and false engine fault indicators resolved completely. Consider having your battery cables and connections thoroughly inspected before pursuing more complex fuel system or ECU diagnostics.

Thanks for sharing those details about the battery connections. My RS6 had nearly identical symptoms last winter. The engine surge and starting issues were incredibly frustrating, especially after multiple failed diagnostic attempts. Your electrical system solution was spot on. After cleaning the connections and replacing one corroded cable, the unusual engine light warnings disappeared completely. The ECU failure warnings also stopped showing up during start attempts. Just curious, do you remember roughly how much the repair ended up costing? And has everything stayed working properly since the fix? My engine diagnostics have been clean for 6 months now but always good to hear about long-term reliability.

Had my battery cables fixed about 3 months ago for 155 Euro and the car runs perfectly now. No more engine surge issues or ECU failure warnings during startup. The mechanic found significant corrosion on the main battery connections, which was causing the intermittent starting problems and unusual engine fault lights. Since fixing those cable connections, engine diagnostics have shown zero errors. The sporadic engine stalling completely stopped, and the electrical system is working exactly as it should. Definitely worth checking the simple things like battery connections before diving into complex fuel injection troubleshooting. Good to hear your RS6 is also running well after addressing similar electrical issues. These problems can be tricky to diagnose since they often mimic more serious engine control malfunctions.

After struggling with my RS6 starting issues, I finally got everything sorted at a new mechanic last week. Total bill came to 180 Euro for cleaning connections, replacing the corroded main battery cable, and running a full engine diagnostic scan to verify the fix. The experience was actually better than expected, they found the electrical problem within an hour. The mechanic showed me how badly corroded the main battery connection had become, which explained all those unusual engine fault warnings and starting problems. Its been running perfectly for the past week. No more ECU failure messages or engine stalling during cold starts. The engine diagnostics are completely clean now. Such a relief to have it properly fixed after those three failed attempts with my previous mechanic.