2018 Cadillac Ct6

The Super Cruise hands-free highway driving system frequently disengages and becomes unavailable, even on mapped highways where it should function. Owners report the system going offline due to GPS signal issues, camera obstruction warnings in clear weather, and driver attention monitor false alarms. The LiDAR map data can also become outdated, causing the system to refuse activation on recently modified highway sections.

Ensure the Super Cruise map data is updated via OnStar or the MyCadillac app. Clean the forward-facing camera lens area on the windshield and the driver attention camera on the steering column. Dealer performs Super Cruise module software updates. If the infrared driver attention camera is faulty, it must be replaced and recalibrated.

The rear air suspension leveling system's compressor fails or runs excessively, causing the rear of the vehicle to sag. Owners notice the rear end sitting lower than normal, especially after the vehicle has been parked overnight. The compressor may run continuously trying to maintain ride height, eventually burning out. Air spring leaks at the fittings are a common contributing cause.

Replace the air suspension compressor and inspect the air springs, lines, and fittings for leaks. A leak test should be performed before replacing the compressor, as a new compressor will also fail prematurely if there is an air leak elsewhere. Replacement air springs and compressors are available from aftermarket suppliers at lower cost than OEM parts.

The CT6's complex electronic architecture with over 30 networked control modules is prone to intermittent communication faults that trigger multiple warning lights and error messages simultaneously. Owners report simultaneous StabiliTrak, ABS, lane departure, and other warnings, sometimes accompanied by a 'Service Vehicle Soon' message. These multi-system faults are often caused by a single module losing communication on the CAN bus.

Dealer performs a full module communication diagnostic scan to identify the module that is dropping off the network. Common causes include corroded ground connections, water intrusion at connector locations, and BCM software glitches. A BCM software update or reprogramming of the offending module often resolves the issue. Check battery voltage and ground connections first.

The 3.0L twin-turbocharged V6 (LGW) develops a wastegate rattle at idle and low RPM, producing a metallic buzzing or chattering sound from the engine bay. The wastegate flapper valves develop play in their pivot points as the bushings wear. While primarily a noise complaint, a worn wastegate can also affect boost control and trigger boost-related codes.

GM issued TSB 18-NA-220 addressing wastegate rattle on the 3.0L twin-turbo. The repair involves replacing the turbocharger assembly with an updated unit that has tighter wastegate tolerances. Both turbochargers should be inspected, as the issue often develops on both sides. The repair is covered under the powertrain warranty if within coverage.

The Bose premium audio system speakers, particularly the door-mounted woofers and the center channel speaker on the dashboard, develop distortion, buzzing, and complete failure. The speaker cone surrounds deteriorate and the voice coils burn out. Owners report progressively worsening audio quality with rattling bass and tinny treble before the speakers fail entirely.

Replace the failed speakers with OEM Bose replacement units or quality aftermarket speakers designed for the CT6 enclosures. The door panel must be removed to access the door speakers. The Bose amplifier should be tested to ensure it is not sending clipped signals that could damage replacement speakers. Aftermarket speaker adapters are available to fit standard speakers into the Bose mounting locations.

General Motors LLC (GM) is recalling certain 2018-2019 Cadillac CT6, Escalade ESV, Chevrolet Suburban, Volt, and GMC Yukon XL vehicles. Certain second-row or third-row rear seatbelts retractor assemblies may not automatically lock when the seatbelt is fully pulled out of the retractor, possibly preventing a child seat from being properly secured. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."

If the child seat is not properly secured in the event of a crash, it can increase the risk of injury.

GM will notify owners, and dealers will inspect the rear seatbelt retractors and replace them if necessary, free of charge. The recall began November 7, 2018. Owners may contact Cadillac customer service at 1-800-458-8006, Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is 18315.

General Motors LLC (GM) is recalling certain 2016-2018 Cadillac CT6 vehicles. The inboard child seat anchorage bars may have had excess structural adhesive applied during assembly, which can interfere with the installation of a child seat. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 225, "Child Restraint Anchorage Systems."

If the child seat cannot be attached correctly to the anchorage bar, there is an increased the risk of injury.

GM will notify owners, and dealers will inspect, remove any excess adhesive, and apply anti-corrosion primer to the inboard child seat anchorage bars, free of charge. The recall began August 3, 2018. Owners may contact Cadillac customer service at 1-800-458-8006. GM's number for this recall is 18228.