VW Passat Mirror Heating Failure: Fix Options & Costs

I had a similar issue with my 2021 VW Golf Hybrid last winter. As someone with moderate experience in car maintenance, I initially thought the heater element was completely dead, but it turned out to be much simpler. The workshop diagnosed a faulty cable connection between the mirror assembly and the door wiring. During cold weather driving, these connections can sometimes work loose or corrode. The rearview mirror heating system stopped working entirely, just like yours. The repair involved accessing the mirror housing and replacing a damaged connector plus securing the cables properly. Total cost was 95€ including diagnostics and labor. No need for a complete mirror replacement in my case. Before you proceed with repairs, could you share: Does the issue affect both side mirrors or just one? Have you noticed any other electrical issues with the mirrors (adjustment, folding)? When did you first notice the problem? What error code are you getting specifically? This information would help determine if your issue matches what I experienced with my Golf or if its something different.

Thanks for sharing your experience. At my last service (2000km ago), everything was fine. Just to add to the discussion, both mirrors are affected and throw error code E-4401. The power folding and adjustment still work perfectly fine. The issue started about 2 weeks ago when temperatures dropped below freezing. Looking at the service manual, it suggests checking cable connections first, but given the dual mirror failure, I suspect it might be related to the car electronics control module. Will try checking the fuses before booking a workshop appointment. Getting this fixed is becoming urgent for safe winter driving conditions. Any thoughts on whether this requires immediate attention?

Based on my experience with the same issue on my Golf, your suspicion about the control module could be right, but I would still lean towards a connection issue given the timing with the cold temperatures. When I dealt with this, I also noticed it started during freezing conditions. The temperature control system for mirror heating often acts up when connections get affected by winter conditions. Even though both mirrors are affected, this can still be caused by corroded or loose connections at a single point where the wiring meets the main harness. The error code E-4401 is a common indicator for mirror heating circuit issues rather than a control module problem. In my case, the workshop found that moisture had gotten into the main door connector, affecting both mirror heating circuits simultaneously while leaving the adjustment functions working. For safe winter driving, while mirror heating is important, you can temporarily use anti-fog sprays or films as a workaround. However, I would recommend getting this checked within the next week or so, moisture issues tend to worsen over time and could eventually affect other electrical components. The fact that power folding still works perfectly suggests the main power supply and control signals are good, which further points to a connection issue rather than a module failure. This matches what I experienced with my Golf before getting it fixed.

Your issue with the mirror heating system matches my situation exactly, and I appreciate the detailed response. The symptoms you described with your Golf mirror repair align perfectly with what I am experiencing, especially since my problems also started during cold weather. I will start by having the workshop check those cable connections and door harness points you mentioned, rather than jumping straight to a complete mirror replacement. The temperature control system being affected by winter conditions makes perfect sense, and I am relieved that the vehicle safety features like power folding still work properly. The heater element diagnosis and repair costs you shared (95€) seem reasonable. Since both my mirrors show the same error code E-4401 and the timing matches freezing temperatures, I will schedule a workshop visit this week. Better to address potential moisture issues now before they cause more extensive electrical problems. I will skip checking the control module for now and focus on the connection points you mentioned. Thanks for helping me narrow down the likely cause, this will save time and money at the workshop. Will update once I get it fixed.