VW Taos Cold Start Problems Signal Faulty PTC Heater

I had a comparable issue with my 2021 VW T-Cross last winter. As someone with moderate experience in car maintenance, I initially thought it was just a regular heating system problem, but it turned out the electrical fault was more complex. The symptoms were exactly like yours, rough cold starts, increased fuel usage, and heating issues. The blower motor was working, but the heating element wasn't functioning correctly. After some basic troubleshooting failed, I took it to my regular workshop. Their diagnostic revealed a defective electric auxiliary heater, which was causing the engine management system to compensate incorrectly during cold starts. The repair involved replacing the PTC heater element and recalibrating the system. Total cost was 350€, including parts and labor. The repair completely resolved the issues, fuel consumption returned to normal, cold starts became smooth again, and the heater repair restored proper temperature control. Before suggesting specific solutions, could you share: Do you notice any unusual sounds from the heater system? What error codes is your system showing? Has the problem gradually gotten worse or did it start suddenly? Have you noticed any other electrical issues? This information would help determine if your Taos is experiencing the same underlying problem.

Just finished my last service 2 weeks ago, and now at 96710km, the problem has worsened considerably. The codes I am getting are P0597 and P0598, which point directly to the thermostat heater control circuit. No unusual sounds from the heating system, but heat output is minimal even after 15 minutes of driving. The blower motor seems to work fine, I can hear it changing speeds normally. The issue started gradually about a month ago and has steadily gotten worse. The only other electrical quirk I have noticed is that sometimes the climate control display flickers briefly when adjusting the temperature settings. No other electrical issues to report. Fuel consumption has increased by roughly 15% since these problems started. Looking at the repair costs you mentioned, I am hoping the fix will be similar, though prices might have changed since your repair.

Thanks for those details. The error codes P0597 and P0598 match exactly what I experienced with my T-Cross, confirming the thermostat heater control circuit issue. That 15% increase in fuel consumption is almost identical to what I saw, mine was around 17% higher before the repair. The flickering display is also a telltale sign of voltage fluctuations in the HVAC system that I noticed too. Since your mileage is higher than when I had my repair (mine was at 78000km), you might want to also have them check the wiring harness. In my case, there was minor insulation wear on some of the heater circuit wiring that they found during the repair. The repair cost nowadays would likely be around 400-450€ based on current parts prices. Make sure they perform a full system diagnostic after replacement, my mechanic had to do two rounds of programming to get the temperature control working properly. One tip: document the fuel consumption increase and keep those error codes. Some component warranties might still apply even at your mileage, especially for the PTC heater since its a known issue in our models.

The flickering display and error codes definitely match up with what you described. Just scheduled an appointment for next week to have it checked out. Good call about documenting the fuel consumption, I have been tracking it through my fuel app since the issues started. My service advisor mentioned they have seen several similar cases with the heating system lately, particularly the PTC heater failures. They quoted me 425€ for the repair including diagnostics and programming, which aligns with what you paid. They also agreed to inspect the wiring harness as part of the service. Will make sure they do a complete temperature control system test after the repair. The electrical fault symptoms you described are so similar to mine that I am fairly confident this is the same issue. Thanks for sharing your experience, it helped me better understand what I am dealing with and what to expect from the repair process. The blower motor is still working fine, so hopefully that means the problem is contained to just the heater circuit. Will update once the repair is done to confirm if this resolved the cold start and fuel consumption issues.