Patriot Diesel Auxiliary Heater Failure Fix Guide

As someone with moderate experience working on diesel vehicles, I had a similar issue with my 2011 Jeep Compass. The heating system completely failed during winter, and the blower motor wouldnt respond at all. After checking with my regular workshop, they discovered a defective glow plug was causing the auxiliary heater malfunction. The heater core and temperature sensor were working fine, but the glow plug issue prevented proper heat control. The total repair cost came to 440 Euro, including diagnostics and labor. However, before jumping to conclusions, it would help to know: Have you noticed any other electrical issues? Does your regular heater still work normally? What error code is showing in your system? Have you had any recent work done on the heating system? These details would help determine if youre facing the same issue I had or if its something else in your heating system components. Different model years can have varying configurations, so knowing these specifics would allow for better troubleshooting advice.

Thanks for the info about the glow plug issue. My latest service was just 2 weeks ago at 196748 KM, and the ventilation system was working fine then. The regular heater works normally, but the auxiliary heater just stopped suddenly without warning. No other electrical problems noted. The blower motor runs fine in all settings. I scheduled a diagnostic check for next week to read the error code, as my regular scanner cant access the auxiliary heater system codes. Total repair costs are my main concern since the car is getting older. 440 Euro for a glow plug repair sounds reasonable if thats the issue here too.

Thanks for the additional details. Since you mentioned your regular heater and blower motor are working normally, this points away from the main heater core or ventilation system issues I experienced. Your symptoms actually sound different from my glow plug problem, as mine affected the entire heating system. The sudden failure without any warning signs is typical for either a control module issue or fuel supply problem in the auxiliary heater unit. In my Patriot, after the glow plug repair, I later faced a similar sudden auxiliary heater failure that turned out to be a clogged fuel line to the heater unit. The fix was much cheaper, around 180 Euro including cleaning and labor. Given your mileage and that the issue appeared right after service, they should check: Fuel lines to the auxiliary heater for blockages, Control module connections for corrosion, Auxiliary pump operation, Fuse condition Getting the error code read is definitely the right first step. Keep in mind auxiliary heater repairs typically range from 180 Euro to 800 Euro depending on the actual fault. The diagnostic fee is usually around 60 Euro but worth it to avoid replacing parts unnecessarily.

Thanks for the thorough follow-up information. I'll make sure to ask the workshop to specifically check those fuel lines and control module connections. The price range of 180-800 Euro helps set my expectations. After your mention of the clogged fuel line being a common issue, I'm actually a bit more optimistic it might be something simple like that, especially since everything was working fine before the recent service. The auxiliary heater not working is inconvenient, but knowing the regular heating system is functioning properly makes the situation less urgent. I'll update once I get the diagnostic results next week. If it turns out to be just a clogged fuel line like in your case, that 180 Euro repair cost would be much more manageable than I initially feared.