2025 Cadillac CT5 Problems: 6 Known Issues

On the 2020-2025 Cadillac CT5, 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 several-amp draw that flattens the battery overnight; GM has revised these modules multiple times. Audio/amp circuits, the BCM, and sticking door/window switches are other documented draw sources on GM platforms.

On the 2024-2025 Cadillac CT5, Owners report Super Cruise repeatedly displays an 'Unavailable' message and cannot be activated; OnStar troubleshooting fails and dealers escalate to GM engineering with no ETA, citing PIC6557B (Super Cruise Unavailable Message, dated Sept. 25, 2024) . Multiple 2025 CT5 owners report the feature did not work from purchase, with open engineering tickets and wait times of months for a fix . The customer paid for a $2,500 option that is non-functional, with some cases escalating to GM buyback.

On the 2020-2025 Cadillac CT5, 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 as early as factory delivery up through ~20,000 miles, and some have waited months for the part. Both standard and Recaro/performance seats are affected.

On the 2020-2025 Cadillac CT5 2.0L Turbo I4 (LSY), 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 piston rings or turbo seals allow oil into the combustion chamber. Symptoms commonly appear between 40,000 and 80,000 miles and are accompanied by low-oil warnings between changes, a lit check-engine light, and sometimes boost/lean codes. The PCV diaphragm is built into the valve cover, so a failed PCV requires valve-cover replacement rather than a standalone valve on some service variants.

On the 2020-2025 Cadillac CT5, 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, combined with the aggressive performance pad compounds, makes the brakes noisy particularly in warm weather and at low speed. This is a comfort/noise issue rather than a stopping-performance defect, but Blackwing carbon-ceramic rotor replacement is extremely expensive if components are damaged.

On the 2020-2025 Cadillac CT5, 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 battery disconnect, TCM update, or reset. Some CT5 owners report persistent shift quality issues even after adaptation. The CT5-V and CT5-V Blackwing have refined calibrations but can still exhibit occasional harsh shifts.