Audi Q5 Won't Start: Clutch Switch May Be the Culprit

Had a similar situation with my 2021 Audi Q3 diesel last winter. Having some experience with electrical issues in modern cars, I first suspected a safety switch problem when multiple systems failed simultaneously. The symptoms matched yours exactly, car would not start, gear display went blank, and cruise control stopped working. The clutch switch turned out to be the culprit, with a faulty connection in the wiring harness. The electrical fault was causing the safety system to prevent engine start. Took it to a workshop where they diagnosed the car stalling and starting issues. They found a damaged wire connection at the clutch switch assembly. Total repair cost was 95 Euro, mainly labor for accessing the switch and fixing the connection. The fix resolved all issues immediately, everything went back to normal operation, including the gear display and cruise control. What transmission type does your Q5 have, manual or automatic? Also, when the starting issues occur, do you notice any specific behavior from the brake pedal? These details would help confirm if your issue matches what I experienced. Before complete failure, did you notice any intermittent issues with the cruise control or gear display? This could help pinpoint if we are dealing with the same root cause.

The same issue occurred on my Q5 (179969 KM) right after the annual service. The gear selector became completely unresponsive before the car refused to start. The safety mechanism kept engaging out of nowhere, making it impossible to shift properly. A faulty switch in the brake pedal assembly was causing the ignition problem. The brake pedal sensor was sending incorrect signals to the transmission control unit. The workshop replaced both the brake switch and its wiring harness. After the repair, all systems returned to normal operation, including the gear display and cruise control functionality. The total repair cost was 285 Euro including parts and labor. The only early warning sign I noticed was an occasional delay when shifting from park to drive, but this symptom was easy to miss at first.

The brake pedal switch failure on your Q5 matches what I encountered. In my Q3, the faulty switch created similar symptoms starting with hesitation in gear changes before progressing to complete gear selector failure. My car also showed the transmission safety lockout, which makes sense given how these systems are interconnected. When the electrical fault occurs in either the brake or clutch switch assembly, the car cannot verify the safe conditions for starting or gear engagement. Looking back, I noticed mine also presented subtle warning signs, occasional gear display flickers and unresponsive moments in the selector before the complete failure. These intermittent electrical issues typically worsen over time until the car starting system refuses to engage completely. The repair cost difference between our cases likely comes from my faulty switch only needing wire repair versus your complete switch replacement. These switches often fail around the 150000-180000 km mark in my experience. Worth mentioning that regular switch inspection during service could prevent these failures. The gear selector and starting issues usually develop gradually before total system shutdown.

Thanks for explaining about the brake switch, that definitely matches my situation. When you mentioned the occasional gear selector delay as an early warning sign, it clicked because I had experienced exactly that but dismissed it at first. The transmission safety lockout makes perfect sense now, especially since the ignition problem started right after that gear display malfunction. My Q5 is automatic, and the shop confirmed the brake pedal sensor was sending incorrect signals, leading to the electrical fault. Interesting point about the regular switch inspection, wish I had known about checking this during routine maintenance. The 285 Euro repair cost was higher than expected, but definitely worth it to resolve all the car stalling and starting issues at once. For anyone reading this later, if you notice even slight hesitation in gear changes or intermittent gear display issues, get the brake and clutch switches checked before a complete system failure occurs. These safety mechanism components are crucial for proper vehicle operation.