Audi S3 Mirror Heater Failure: Fix Costs & Solutions

Experienced the same electrical fault with mirror heaters on an Audi A4 2015. The problem turned out to be corroded wiring connectors behind both door panels, causing the heater elements to fail. The repair required: Complete removal of door panels, Replacement of wiring harness connectors, Testing of mirror heating circuits, Clearing stored error codes This was a moderate repair job requiring specialized diagnostic equipment to properly identify the failing components. The issue can spread to other electrical systems if left unchecked, as corrosion tends to travel along wiring paths. The rearview mirror heating system shares some circuits with window controls and door locks, so addressing it early prevents cascading electrical problems. In my case, the repair shop found early signs of corrosion affecting the window control module as well. Mirror replacement wasnt necessary since the heater elements themselves were functional, the fault was purely in the wiring connections. After repair, the system worked perfectly and no error codes returned. For reference, the mileage on my A4 was around 165000km when this issue occurred. This is a known weak point in these models and usually appears after extended exposure to moisture.

Thanks for sharing your experience with the mirror heating issue. The symptoms sound very similar to what Im facing with my S3. Did you manage to fix the electrical fault permanently or have you had any recurring problems since the repair? Im especially concerned about those corrosion issues spreading to other electrical systems. Since my car has slightly higher mileage at 174k, Im wondering if I should expect more extensive repairs. Mind sharing what the total repair cost was? Would help me know what to expect when I take it to the shop. The temperature control system in these cars can be tricky, so Im trying to gather as much info as possible before making a decision.

After my previous post, I had the rearview mirror heating system repaired and can report a complete fix. The car electronics specialist found a faulty connection in the wiring harness, similar to what I described earlier. The repair cost came to 95 Euro, which covered diagnosing and fixing the cable connections, much less expensive than I initially feared. The temperature control for both mirrors now works flawlessly. No error codes have returned since the repair, and the heater elements function perfectly in cold conditions. The technician checked surrounding electrical components and found no signs of corrosion spreading to other systems. For reference, its been 6 months since the repair with zero recurring issues. The key was finding a shop that specifically understood these electrical systems rather than attempting temporary fixes. They also verified all mirror heating functions through multiple test cycles. Your mileage being similar suggests you might be dealing with the same type of connection problem rather than a more serious electrical fault. Getting it checked soon would be wise to prevent any potential spread to other circuits.

Based on the conversation, I took my S3 to a specialized Audi electronics shop last week. The diagnosis confirmed exactly what you mentioned, corroded wiring connectors behind the door panels were causing the mirror heating failure. The repair involved: Thorough electrical system diagnosis, Replacing both door wiring harness connectors, Testing mirror heating elements, Clearing fault codes from system Total cost came to 120 Euro, slightly more than yours but still reasonable. The winter driving conditions made me nervous about postponing the fix. The temperature control for both mirrors now works perfectly, and all error codes are gone. The shop did a great job explaining the repair process and showed me the corroded parts they removed. They also checked surrounding electrical components, finding no signs of spreading issues. Really glad I addressed this before it affected other systems. The car mirror heating now activates instantly when needed, and Im confident the fix will last. Much better experience than my previous repair shop visit.