Cadillac Climate Control Chaos: Multiple System Failures

Having experienced similar issues with my 2019 Cadillac CT6, I can share some insight as someone with moderate car repair experience. The symptoms you describe closely match what I encountered. My problems started with the AC failing, followed by other climate control malfunctions. After initial sensor calibration attempts failed, my workshop discovered the root cause was a faulty wiring connection near the humidity sensor module. The repair involved: Testing all climate control sensors, Locating a damaged cable harness connector, Replacing the corroded plug connection, Performing a system reset Total cost was 95€ for parts and labor. The fix resolved all climate control issues simultaneously. Before jumping to conclusions, could you provide: Any specific error codes shown, Whether the issues started gradually or all at once, If the problems vary with outside temperature, Whether the climate control panel lights work normally This information would help determine if your car sensor issues match what I experienced or point to a different underlying problem. A proper diagnosis is crucial since multiple climate control failures often trace back to a single malfunctioning connection rather than multiple broken components.

Thanks for the comprehensive troubleshooting suggestions. Had my latest service at 175000 KM and noticed these issues right after. The error code is P0532. Just checked all fuses for the climate control system and they seem intact. The windshield fogging has become really problematic, especially during morning drives, which makes me think the electrical issue might be more complex than just sensor calibration problems. The climate control panel lights flicker occasionally, and all issues appeared within the same week. Visibility gets worse when temperatures drop below freezing. Would testing the ground connections be a good next step before taking it to a shop?

Thanks for the additional details. My CT6 also showed the P0532 code, which points to the AC pressure sensor circuit being low voltage, exactly what I dealt with after my 170000 KM service. The flickering control panel lights combined with multiple climate control failures strongly suggests an electrical issue, just like in my case. The windshield fogging and visibility problems in cold weather are classic symptoms of a malfunctioning humidity sensor not properly communicating with the climate control system. Testing ground connections is definitely a smart next step. In my situation, corrosion at a ground point had caused poor conductivity, leading to similar dashboard warning signals and system malfunctions. Check especially the connections near the firewall where the humidity sensor wiring runs. However, based on matching symptoms and circumstances, I suspect youll find the same root cause I did, that damaged wiring connector near the sensor module. The combination of: Post-service timing, Multiple climate control failures, Flickering displays, Cold weather sensitivity All mirror my experience exactly. While checking grounds is worthwhile, preparing for professional diagnosis might save time given the complexity of the electrical issue.

The ground connections seem like a good starting point, but Im worried its beyond my DIY skills given how many systems are affected. My visibility issues are getting worse each morning, and I cant risk driving with unreliable defrosting. The timing after the 175000 KM service cant be coincidental. Will have my regular workshop check those wiring connectors near the sensor module first, since the symptoms match your case so closely. The malfunctioning climate control is probably not worth trying to fix myself if theres a risk of damaging more electrical components. The car sensor and connection issues you described make sense given the P0532 code. Ill get it booked in next week and have them start with the firewall area wiring inspection. Really hoping its just that connector and not a more expensive electrical issue requiring multiple component replacements. Thanks for sharing your experience, saved me from replacing parts out of nowhere) hoping to fix the problem. Will update once I know what they find.