Phaeton Climate Control Failure, Expert Help Needed

Had the same temperature control issues on my 2009 VW Touareg V6 TDI. The climate control system completely stopped responding, with error codes appearing on the display. The root cause was traced to faulty wiring connections between the interior temperature sensor and the HVAC control module. The sensor itself was working, but corrosion in the connector plug created intermittent signal problems. This is a known weak point in the HVAC sensor system of these models. The repair required removing parts of the dashboard to access and clean the connector pins, plus replacing the main temperature sensor harness. While not a major mechanical issue, it needed specialized diagnostic equipment to properly test the climate control signals and verify the fix. This type of HVAC sensor failure is fairly common on VW models from that era. The automatic temperature control issues typically start with inconsistent readings before complete failure. Getting it fixed early prevents more extensive damage to the climate control module. Worth noting the problem can also be caused by a failed control module rather than just sensor issues. Proper diagnosis with a VW-specific scan tool is essential to identify the exact cause.

Thanks for the detailed info about the temperature sensor and wiring issue. My Phaeton is showing those exact same symptoms with the climate control system. The error codes and unresponsive controls match perfectly with what you described. Can you remember roughly how much the repair cost in your case? Also curious if youve had any other HVAC sensor problems since getting it fixed? Im debating whether to try the connector cleaning first or just replace the entire temperature control harness to be safe.

I ended up taking it to a different shop for proper sensor diagnostics and they identified the exact same climate control issue you have. The interior temperature sensor wasn't responding due to a damaged cable connection, just as I suspected from my previous experience. The repair was straightforward once they located the faulty wiring, total cost came to 95€ including labor to access and fix the connection. Much less expensive than replacing the entire HVAC sensor system or control module. Since getting the temperature sensor fixed six months ago, the climate control has worked flawlessly. No more error codes or problems with the automatic temperature regulation. Based on this, I'd recommend going straight for the wiring repair rather than just cleaning the connectors, as damaged cables tend to cause recurring issues. The key is having a shop that knows how to properly diagnose these climate issues. They need the right diagnostic equipment to test the sensor signals and pinpoint where the connection is failing in the HVAC system.

After reading about similar HVAC sensor problems, I decided to try a different repair shop this time. I brought my Phaeton in and explained the temperature control issues I was experiencing. The new technician immediately recognized the symptoms and had the proper diagnostic tools to test the climate control system. Turns out the problem was exactly what others described, a damaged wire connection to the interior temperature sensor. The repair only took about two hours and cost 110€, which included accessing the wiring harness and replacing the faulty connection. The automatic temperature control started working perfectly right after the fix. No more error codes or issues with the AC. Really glad I switched repair shops, their expertise with climate control systems saved me from unnecessarily replacing the entire HVAC sensor assembly. The sensor replacement could have cost several hundred Euro if I had gone back to my previous mechanic who might have just swapped parts without proper diagnosis. Sometimes finding the right shop makes all the difference when dealing with complex temperature control problems.