Cadillac · Known Issues
2021 Cadillac CT5 Problems: 18 Known Issues
2021 model year · 405+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2021 model year · 405+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
Interest applies to the selected vehicle and configuration; it is not a reservation. Voting stores a first-party identifier for up to 180 days to prevent repeat votes. No account or email is needed. Clearing cookies or using another device may count separately. Privacy
Visual coming soon
Your interest helps us choose what to build next.
Visual Known Issues · Coming soon
$4.99/month plus taxes at launch · No payment today
According to Au7o's analysis of 405+ owner reports, the 2021 Cadillac CT5 has 18 documented known issues, with 7 rated critical. The most serious are GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure ($0-$0 repair), LT4 Supercharged V8 Premature Engine Failure ($0-$15,000 repair), 10L80 Harsh Shifts and Check Engine Light with DTC P2812 or P2814 (Line Pressure Solenoid) ($0-$3,500 repair), Roof-Rail Side-Curtain Airbags May Be Installed Incorrectly (Recall 21V611), 10-Speed Transmission Damage Can Cause Wheel Lock-Up (Recall 25V148), Daytime Running Lights May Stay On with Headlights (Recall 22V903) and Airbag Warning Lamp May Not Illuminate Consistently (Recall 21V421). The most commonly reported issue is GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure with 320 owner reports. Across all issues with published estimates, repair costs range from $75 to $15,000. DIY maintenance guides at au7o.io.
POWER TRAIN:AUTOMATIC TRANSMISSION
General Motors LLC (GM) is recalling certain 2019-2020 Cadillac CT6, 2020-2021 CT4, CT5, and 2020-2022 Chevrolet Camaro vehicles equipped with a 10-speed transmission. The transmission may become damaged internally and cause the wheels to lock-up.
EXTERIOR LIGHTING:LIGHTING CONTROL MODULE:SOFTWARE
General Motors, LLC (GM) is recalling certain 2020-2023 Cadillac CT4 and CT5; 2021-2023 Buick Envision; and 2022-2023 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The daytime running lights (DRLs) may not deactivate when the headlights are on. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."
AIR BAGS:SRS MALFUNCTION WARNING LAMP/LIGHT
General Motors, LLC (GM) is recalling certain 2021 Buick Envision, Cadillac CT4, CT5, Escalade, Escalade ESV, Chevrolet Tahoe, Corvette, Suburban, GMC Yukon, Yukon XL vehicles. The communications gateway module incorrectly processes a loss of communication with the sensing diagnostic module (SDM), causing the air bag malfunction indicator light to inconsistently illuminate.
AIR BAGS:SIDE/WINDOW:CURTAIN
General Motors, LLC. (GM) is recalling certain 2020-2022 Cadillac CT4 and CT5 vehicles. The roof rail side-curtain air bags may not have been installed correctly, which could result in an improper air bag deployment during a crash.
Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.
Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.
According to Au7o's analysis of 405+ owner reports, the 2021 Cadillac CT5 has 18 documented issues. The most frequently reported are: GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure, LT4 Supercharged V8 Premature Engine Failure, 10L80 Harsh Shifts and Check Engine Light with DTC P2812 or P2814 (Line Pressure Solenoid). Of these, 7 are rated critical and should be addressed promptly.
The 2021 Cadillac CT5 has 18 known issues documented across 405+ owner reports. 7 issues are rated critical: GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure and LT4 Supercharged V8 Premature Engine Failure and 10L80 Harsh Shifts and Check Engine Light with DTC P2812 or P2814 (Line Pressure Solenoid) and Roof-Rail Side-Curtain Airbags May Be Installed Incorrectly (Recall 21V611) and 10-Speed Transmission Damage Can Cause Wheel Lock-Up (Recall 25V148) and Daytime Running Lights May Stay On with Headlights (Recall 22V903) and Airbag Warning Lamp May Not Illuminate Consistently (Recall 21V421). Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Cadillac CT5 issues range from $0 to $15,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure, typically costs $0-$0 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
After widespread engine failures and an NHTSA investigation, GM recalled all 2021-2024 vehicles equipped with the 6.2L V8 engine including the CT5-V. The recall addresses potential connecting rod bearing failure that can cause engine seizure, stalling, or fire risk. The recall co… Repairs typically run $0-$0. Severity: high.
The 6.2L supercharged LT4 V8 in CT5-V Blackwing models has experienced premature engine failures including bottom-end bearing failures, lifter collapse, and metal shavings found in oil. Failures have been reported as early as 5,000-15,000 miles. Car and Driver documented a catast… Repairs typically run $0-$15,000. Severity: high.
Owners of 2020-2021 Cadillac CT5 and CT5-V models equipped with the GM Hydra-Matic 10L80 10-speed automatic report harsh, abrupt shifts accompanied by an illuminated check engine light. GM Preliminary Information bulletin PIP5799 documents an electrical fault in Transmission Cont… Repairs typically run $0-$3,500. Severity: high.
On certain 2020-2022 Cadillac CT5 vehicles, the roof-rail side-curtain airbags may not have been installed correctly and may deploy improperly in a crash. Severity: high.
Certain 2020-2021 Cadillac CT5 vehicles equipped with a 10-speed transmission can develop internal transmission damage that may cause the wheels to lock while driving. Severity: high.
On certain 2020-2023 Cadillac CT5 vehicles, the daytime running lights may not deactivate when the headlights are on, creating excess glare and failing FMVSS 108. Severity: high.
On certain 2021 Cadillac CT5 vehicles, the communications gateway module can process loss of communication with the sensing and diagnostic module incorrectly, causing inconsistent illumination of the airbag malfunction indicator. Severity: high.
Owners of four-cylinder CT5 550T (and CT4-shared LSY platform) models report higher-than-expected oil consumption, often exceeding GM's 'acceptable' threshold of one quart per ~2,000 miles. The valve-cover-integrated PCV system is a frequent contributor, and on worse cases worn p… Repairs typically run $150-$4,500. Severity: medium.
The CT5 pairs both its 2.0L turbo and 3.0L twin-turbo engines with a GM 10-speed automatic (10L80/10L90), which can develop a torque converter clutch (TCC) shudder felt as a vibration or 'rumble-strip' shake, typically at light throttle and steady cruise (roughly 25-55 mph) when… Repairs typically run $300-$2,500. Severity: medium.
The 2.0T turbocharged four-cylinder (LSY) in the CT5 can develop oil leaks from the timing cover gasket. The gasket develops cracks after heat cycling, causing oil to seep from the front of the engine. In some cases, this leads to noticeable oil consumption between changes. GM re… Repairs typically run $500-$1,500. Severity: medium.
Owners report the 12V battery going dead when the car sits, with factory batteries dying in as little as two years. Beyond normal high parasitic draw of modern electronics, a recurring GM culprit is the driver-seat control module / Memory Seat Module (MSM), which can develop a se… Repairs typically run $250-$900. Severity: medium.
Owners report the digital Instrument Panel Cluster / Driver Information Center (the gauge/speedometer display) going completely blank for the remainder of an ignition cycle, most commonly on cycles that follow a remote start. GM addressed this in Technical Service Bulletin 21-NA-… Repairs typically run $75-$300. Severity: medium.
A widely reported CT5 interior failure: the driver-seat massage and adjustable lumbar/bolster functions stop working. Dealers diagnose this as a failed seat 'module' — an all-in-one air-pump, valve and electronics unit feeding the seat air bladders. Owners report the failure from… Repairs typically run $350-$1,200. Severity: medium.
Owners of sunroof-equipped CT5 models report creaking and rattling from the roof/sunroof and headliner area, especially over bumps and at speed. GM has a related sunroof-creak service bulletin (TSB 19-NA-096) that calls for dropping the headliner and torquing the sunroof module b… Repairs typically run $100-$600. Severity: low.
A common cosmetic defect on 2020-2024 CT5 models: the gloss-black exterior B-pillar appliqués and window-surround trim bubble, haze, and delaminate, with the clear top layer lifting and flaking to expose a dull layer beneath. Owners describe small bubbles or a milky look first, p… Repairs typically run $0-$500. Severity: low.
CT5 owners report a persistent whistle or high-pitched 'tone' (described as ringing in the ears) at highway speeds, typically 65 mph and up, plus buzzing from the door/window/headliner area at 50+ mph. Sources isolated by owners and dealers include the windshield weatherstrip lif… Repairs typically run $100-$600. Severity: low.
CT5 and CT5-V owners (and especially CT5-V Blackwing buyers with the optional Brembo carbon-ceramic package) report loud brake squeal, and at low speed a grindy or metal-on-metal sound, sometimes as early as ~5,000 miles. The copper-free friction-material formulation now mandated… Repairs typically run $250-$3,000. Severity: low.
The CT5 uses GM's 10-speed automatic (10L80) that can exhibit harsh shifts, delayed engagement, and shift hunting, particularly when the adaptive learning resets. The 10-speed has very complex shift logic and can take 500+ miles to fully adapt to a driver's pattern after a batter… Repairs typically run $0-$500. Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.