S4 Won't Start: Shifter Lock & Engine Issues Combined

Having experienced similar transmission issues with my 2005 A4 2.0T, these symptoms strongly point to a failing transmission control unit. The gear shifter feeling loose combined with rough shifting patterns and starting problems typically indicates the transmission sensor system has degraded. When my A4 showed these exact signs, the automatic transmission started behaving erratically. The main issue was the control unit not properly communicating with the transmission sensors. This created a chain reaction affecting multiple systems, including the shift lock and engine start functions. The problem required replacing the transmission control module and recalibrating the entire transmission system. This was not a quick fix job, the transmission had to be partially dismantled to access and replace the affected components. Its definitely a serious issue that needs immediate professional attention, as continuing to drive with these symptoms risks complete transmission failure. The check engine light in your case is likely triggered by transmission-related fault codes. Would strongly suggest getting it scanned for specific transmission sensor codes before attempting any repairs. Based on these symptoms, you need a specialized transmission shop rather than a general mechanic. The combination of starting issues and loose gear shifter often indicates electrical problems in the transmission control system rather than mechanical wear.

Thanks for the detailed explanation regarding the transmission control unit issue. This really helps as I am experiencing identical symptoms with my S4, especially the erratic automatic transmission behavior and problematic shift lock. I replaced the module last month and the transmission repair has resolved most of the issues, though I still notice occasional rough shifts when cold. Could you share approximately how much you paid for the full repair? Also wondering if you have encountered any other transmission-related problems since the fix? For reference, my car is currently showing the same fault codes in Neutral position that you mentioned, so your insight would be very helpful.

The transmission repair on my A4 has worked out great since getting it fixed by a transmission specialist. The automatic transmission now shifts smoothly and the park brake engages correctly every time. Total cost came to 1000 Euro to replace the affected control unit, which resolved the problematic shift lock and erratic behavior. Regarding your cold shifting issue, this is fairly normal for these transmissions and usually improves once the fluid warms up. The occasional rough shift when cold shouldnt be a major concern as long as it smooths out after warming up. Since fixing the control unit, I havent experienced any transmission issues or fault codes. The specialist confirmed that transmission failure was likely if the problem had been left unaddressed. Having the control unit replaced was definitely the right call, as it restored proper communication between the transmission components. The fault codes youre seeing in neutral position suggest your transmission control module might need similar attention. Would recommend getting it diagnosed soon to prevent more serious transmission problems from developing.

After dealing with my problematic S4 transmission issues, I finally got everything sorted out at a specialized transmission shop. They diagnosed and fixed the failing control unit that was causing all those concerning symptoms. The transmission repair cost me 1600 Euro total, but it was worth every cent. The shop found multiple transmission sensor faults that were causing the gear shifter to feel loose and the erratic shifting behavior. They had to remove part of the transmission to access and replace the control module. The neutral position now engages properly and the shift lock works perfectly. Three weeks after the repair, my S4 shifts like new. No more check engine lights or starting problems. Glad I switched to a transmission specialist instead of going back to my regular mechanic. The expertise made all the difference in getting it fixed right the first time. I appreciated everyones input here, it helped me understand what I was dealing with and pushed me to seek out the right kind of help. The transmission shop confirmed that catching this early prevented much more expensive transmission failure down the road.