VW Suran Heater & Aux Control System Failure Fix Guide

Had the same auxiliary heater failure on my 2017 VW Golf TSI last winter. The car heater system showed similar symptoms, climate control errors and complete auxiliary heating failure. The root cause was a combination of issues: corroded electrical connections to the heater control module and a coolant leak affecting the auxiliary heating unit. The coolant leak was dripping onto electrical components, causing shorts in the system. This turned out to be a serious repair requiring: Complete removal of the auxiliary heater unit, Replacement of damaged wiring harness, New heater control module installation, Fixing the coolant leak, System reprogramming The heat control issues can worsen if left unaddressed, potentially leading to complete heating system failure. The repair took 3 full days at the shop due to the complexity of accessing and testing all components. Would strongly recommend getting this checked soon, as auxiliary heater problems often indicate underlying issues with the main heating system. A qualified VW specialist should perform a full diagnostic of both the electrical and cooling systems to prevent further damage. Best approach is having them check for coolant leaks first, then move on to electrical testing of the heat control modules.

Had a very similar auxiliary heater problem resolved about 6 months ago. The temperature sensor and blower motor were also affected due to coolant leak damage. Your symptoms sound exactly like what I experienced with my Suran Spacefox. The heater core needed replacement along with several electrical components. Very interested to hear how much your repair ended up costing and if youve had any lingering issues since getting it fixed? My repair took about 4 days total at the shop. Did they also suggest replacing the entire heat control module in your case? Or were you able to get by with just fixing the leak and damaged wiring?

Had everything fully repaired at a certified shop. The auxiliary heater is now working perfectly after addressing the glow plug which turned out to be defective. Total repair cost came to 440€ which included parts and labor. Unlike your case, my temperature sensor and blower motor were still functioning properly, so we didnt need to replace those components. The mechanic did inspect the heater core thoroughly but found it was in good condition, just needed a thorough cleaning after the coolant leak was fixed. The heat control module ended up being fine once the electrical connections were cleaned and properly sealed. No lingering issues since the repair, car heater system works like new and all error codes have cleared. The auxiliary heating now starts up immediately when activated. Much simpler fix than initially expected, since we caught it before the coolant leak could cause more extensive damage to other components. Regular system checks since the repair show everything operating within normal parameters.

Just got back from the mechanic after dealing with my heating system issues. The diagnosis matched what you experienced, faulty glow plug causing the auxiliary heater problems. My repair was more extensive though, as the coolant leak had already damaged multiple components. The final bill hit 890€ covering replacement of the temperature sensor, damaged wiring, and a thorough heater core flush. The climate control system needed recalibration after all the work. Took them 3 days to complete everything, but the heating works perfectly now. Really glad I didnt wait longer to get it fixed. The mechanic showed me how the coolant leak was starting to corrode other nearby components. Could have ended up being much more expensive if left unchecked. At least now I know what warning signs to watch for with the auxiliary heater system.