SQ7 Mirror Heater Failure During Cold Weather

Experienced this exact issue on my S6 (2020 gasoline). The mirror heating failure during cold weather driving turned out to be a common fault with the wiring harness connection to the mirror heating element. In my case, the cable connection had corroded due to moisture getting into the mirror housing. The fix required removing the mirror housing and replacing the wiring connector assembly. This is not a major repair but needs proper diagnostic equipment to verify the exact point of failure. The temperature control module stores the error code because it detects the circuit break in the heating element system. While my mirror replacement wasnt necessary, the wiring harness and connector needed complete replacement to restore proper winter driving functionality. The fault often appears suddenly during winter driving because the corroded connections finally give out under the extra power draw from the heating element. Since your other electrical systems work fine, this points strongly to a localized connection issue rather than a more serious system-wide problem. A qualified shop should be able to diagnose and repair this without major component replacement, assuming the heating element itself isnt damaged.

Thanks for the detailed response on the mirror heating issue. Mine actually turned out nearly identical, faulty wiring causing the rearview mirror heating to fail during a particularly bad cold weather spell. I had the harness connector replaced and the vehicle safety system is now showing all clear. Good to hear I wasnt the only one dealing with this in a relatively new car. How much did the car mirror repair cost you in the end? Also wondering if youve had any other electrical gremlins pop up since the fix?

Had my heater element repair done last week. The final bill came to 95 Euro for fixing the faulty cable connection at the mirror housing. Much cheaper than initially feared when the rearview mirror heating failed. The mechanic found moisture had gotten into the connector, causing corrosion, exactly like my earlier diagnosis suggested. After the repair, the temperature control system is working flawlessly even in cold weather conditions. The vehicle safety system shows no more error codes. No other electrical issues have surfaced since the fix. The repair shop did a thorough check of surrounding components while they had the mirror housing open, confirming everything else was in good condition. The original problem was isolated to just that one connection point. Good to hear you got yours sorted with a similar repair. These connector issues seem to be a weak point in our models, but at least its a straightforward fix when caught early.

Thanks for the input. Just got back from the shop and wanted to share my experience. They diagnosed and fixed my mirror heating issue in about 2 hours. The final cost was 120 Euro, which included a full diagnostic scan and the wiring harness replacement. The car electronics specialist confirmed it was indeed a corroded connector causing the electrical fault in the mirror assembly. They showed me the damaged part, pretty obvious why the winter driving features were acting up. The moisture had completely eaten through the connection. The temperature control system now works perfectly and all error codes are cleared. No other issues found during their inspection, which is a relief. Much better experience than my last mechanic visit and the repair cost was reasonable. Great to know this is a known issue with a straightforward fix. Definitely feeling more confident about handling similar problems in the future.