Cadillac CT4 Bluetooth Mic Dead: Can't Make Calls

Had the exact same issue on my 2016 Cadillac CTS. The wireless connection would pair normally but the audio input was completely dead during calls, plus speech recognition stopped responding to commands. After troubleshooting, it turned out the microphone unit in the overhead console was defective. The ambient noise sensor had failed, causing the system to block all voice inputs. This is actually a known fault pattern in some Cadillac infotainment systems from that generation. The repair required removing the headliner to access and replace the complete microphone assembly. This was not a quick fix, the entire job took several hours because accessing the components meant carefully removing multiple trim pieces. In my case, the Bluetooth issue was definitely tied to the faulty microphone hardware, not a software problem. Basic diagnostic scans often miss this since the microphone failure doesnt always trigger obvious error codes. This is considered a serious repair since it involves interior disassembly and specialized parts. Would strongly recommend having this done at a shop with specific experience in Cadillac infotainment systems rather than a general mechanic.

Really appreciate your detailed reply about the microphone repair issue. Your experience matches what I am seeing with my CT4 sound quality problems. The voice recognition and call audio symptoms are identical. Good to know about the ambient noise sensor being the root cause. Did you track how much the complete repair ended up costing? Also curious if your audio system has been working properly since the fix or if you have encountered any other volume control glitches? Agree that finding someone who really knows these systems is key. The general shop I tried clearly wasnt familiar enough with the CT4 infotainment setup to properly diagnose it.

Just got the repair completed last week and can confirm everything works perfectly now. The entire microphone repair job, including the ambient noise sensor replacement and complete infotainment system check, came to 815€. The wireless connection quality is now excellent, calls are crystal clear and the voice recognition responds perfectly to commands. No volume control issues or audio input problems since the fix. The audio system is performing exactly as it should. Having a specialist handle it was definitely worth the investment. They knew exactly where to look and how to access the components without damaging the headliner or surrounding trim. The Bluetooth issue was resolved completely, and the ambient noise calibration is working as designed. For anyone dealing with similar hands-free system problems, having the proper diagnostic equipment and expertise makes all the difference. A general shop might miss the underlying microphone repair requirements that are specific to these Cadillac systems.

Thanks everyone for the guidance. After getting your feedback, I took my CT4 to a certified electronics specialist last month. Turned out you were spot on, the microphone assembly needed replacement. The repair came to 790€ which included a complete system diagnostic. They had to remove quite a bit of the interior trim to access the faulty components, but the techs clearly knew what they were doing. The whole job took about 4 hours. Since the fix, the audio system is working perfectly. Phone calls are crystal clear, speech recognition responds to every command, and the ambient noise filtering works like new. The Bluetooth connection has been rock solid with no volume control issues. Really glad I avoided more wasted time at general repair shops. Having someone who specifically understood these infotainment systems made all the difference. The extra cost for a specialist was worth every cent for a proper fix.