Rough Cold Start & Heavy Fuel Usage Points to PTC Heater

Had the exact same problem on my 2011 Chrysler 300 last winter. Have some experience with basic car maintenance, but this was definitely beyond DIY territory. The temperature control system was acting up, showing similar symptoms, rough cold starts and increased fuel consumption. The blower motor worked fine, but the cold air coming through suggested an electrical fault in the PTC heater system. Took it to a workshop where they diagnosed a faulty electrical auxiliary heater. The repair included replacing the PTC heater assembly and reprogramming the control module. Total cost was 350€, which included parts and labor. The symptoms disappeared completely after the fix. No more rough starts, fuel consumption went back to normal, and the heating system works perfectly now. To provide more specific advice for your case, could you share: Are you getting any specific error codes with the check engine light? Does the heating system produce any heat at all? Have you noticed any unusual electrical issues? What does the fuel consumption increase look like in numbers? These details would help determine if your issue matches what I experienced.

Just had my 24648 KM service done last month, and wanted to add my experience here. The rough cold start combined with high fuel consumption definitely sounds familiar. In my case, it turned out the heat not working properly was actually connected to an electrical fault in the PTC system. The workshop ran diagnostics and found the cold air issue was caused by a failing heating element, not the blower motor as I initially thought. The heater repair involved replacing both the PTC element and some related wiring. After fixing it, the engine started smoothly even in cold conditions and fuel consumption returned to normal. The error code I got was P0597, though yours might be different. Suggest getting the code read before making any assumptions about the repair needed.

Based on our similar Chrysler experiences, the symptoms you describe match exactly what I encountered. The P0597 code you mentioned is indeed related to the thermostat heater control circuit, which aligns with my previous PTC heater repair. After getting my 300 fixed, I also noticed the HVAC system performance improved significantly. The heating element replacement solved not just the cold start issues but also brought the fuel economy back to normal levels. Before the repair, my consumption had increased by about 15-20%. One thing worth mentioning, the wiring repair you had done was actually smart preventive maintenance. In my case, they only replaced the heating element initially, but I had to go back a month later for wiring issues. The complete repair would have been cheaper if done all at once. Since you mentioned getting the service done recently, make sure to monitor your cold start performance over the next few weeks. My PTC heater issues first appeared intermittently before becoming a constant problem. If you notice any regression, get it checked immediately to prevent additional electrical system complications. The workshop cost seems reasonable compared to what I paid for the repair on my 300. These heating system repairs typically range between 300-450€ depending on the extent of wiring work needed.

Thanks for all the input. Just wanted to close this thread with a final update. After getting my Pacifica fixed, I can confirm the heating element was indeed the main problem. The cold air and rough starts were exactly the symptoms others mentioned. The temperature control system works perfectly now after the heater repair. Workshop found extensive wiring damage near the PTC unit, which explained the electrical fault causing all those issues. Total cost was 420€ for parts and labor, right in line with what others paid. Important learning: when rough cold starts combine with heating issues and high fuel use, check the PTC system first. The error code P0597 pointed straight to the problem. Really glad I got this sorted before winter, no more cold air blasting through the vents. Big thanks to everyone who shared their experiences. This forum helped me understand the issue and get the right fix done the first time around.