2023 Cadillac XT6 Problems: 10 Known Issues

On the 2021-2023 Cadillac XT6, an internal short inside the K111 Fuel Pump Driver Control Module (FPDCM, also called the fuel pump power control module) can cause a cluster of drivability faults on 2021-2023 Cadillac XT6 vehicles. GM documented this first as preliminary information PIP5964 and then as service bulletin 24-NA-139, published July 2024, which replaces PIP5964D. The symptom set is broad and misleading: crank-but-no-start, stalling while driving, loss of power, rough idle, erratic shifting, and an inoperative or erratic fuel gauge, all with the check engine light on and multiple codes stored. Because the module drives fuel pump speed, technicians may chase a failing in-tank pump or a transmission concern before finding the module. The bulletin directs module replacement when P023F and/or P129F are set and diagnostics find no other cause. Owner reports of the failure exist on the Cadillac Owners Forum, including a 2021 XT6 Sport that would not start with P023F stored.

On the 2020-2025 Cadillac XT6, the auto start-stop system engages and disengages harshly, causing the vehicle to shudder on restart. The AGM battery required for the system degrades quickly, and when it weakens, the start-stop system becomes erratic or disables itself. Many owners find the system intrusive.

On the 2023 Cadillac XT6 3.6L V6 (LGX), nHTSA campaign 23V172000 (GM safety recall N222389310) covers 613 model-year 2023 Cadillac XT6 vehicles built with an incorrect sun gear inside the transmission's final drive. The wrong gear does not retain the driver-side (left front) half-shaft correctly, and the shaft can disengage from the transmission. Two failure modes follow: while driving, the wheel stops receiving torque and the vehicle loses drive power; while parked, the park pawl can no longer hold the vehicle through a disengaged shaft, so the XT6 can roll away even with the shifter in Park. The same wrong-gear condition was recalled on the Cadillac XT5, Chevrolet Blazer and Traverse, and GMC Acadia, but confirm your own VIN rather than assuming a sibling's campaign applies.

On the 2020-2025 Cadillac XT6, the Power Transfer Unit (PTU) on AWD-equipped XT6 models develops seal leaks that allow fluid to seep out. Low PTU fluid causes the internal gears and bearings to wear prematurely, eventually producing a whining noise. The PTU is not included in routine maintenance schedules, so leaks often go unnoticed.

On the 2020-2023 Cadillac XT6, xT6 owners report a "Steering Assist is Reduced — Drive with Care" or "Service Power Steering" message in the driver information center, usually with a noticeable increase in steering effort. GM bulletin 20-NA-215 covers this condition on XT5 and XT6 vehicles built between September 28 and October 22, 2020, and ties it to DTCs C0460 and/or C0545 stored in the power steering module. The XT6 uses a belt-drive electric rack with the motor and control module integrated into the steering gear; per the bulletin, internal components can make interference contact as the wheel turns, grounding and damaging internal electrical parts, which sets the code and the module deliberately cuts or reduces assist rather than allowing erratic assist. Steering is still mechanically connected — the car remains steerable — but effort rises sharply, which is most alarming at parking-lot speeds or in an evasive maneuver. Owners also describe a separate, milder version where assist fades after sustained low-speed maneuvering and returns once the system cools; that thermal derate is normal protection, not a failed rack, and it clears itself.

On the 2020-2024 Cadillac XT6 2.0L Turbo I4 (LSY), gM bulletin PIP5863B addresses an illuminated malfunction indicator lamp with DTC U0672, lost communication with electric engine coolant pump G59. Its North American applicability includes XT6 vehicles with the 2.0L LSY engine. A pump-connection problem is a potential cause; the code alone does not establish a failed pump.

On the 2020-2023 Cadillac XT6 3.6L V6 (LGX), p0128 requires diagnosis before replacing parts. PIP5940 covers thermostat replacement on 2020–2023 XT6 vehicles with the 3.6L LGX and changes the repair to the thermostat housing rather than an unnecessary pipe-and-outlet assembly. It does not establish a failure rate. Separately, GM 22-NA-054 identifies a possible ECM calibration timing error on 2021 XT6 LGX vehicles with P0128, a check-engine warning, an inoperative temperature gauge or fans running after shutdown.

On the 2020-2025 Cadillac XT6 3.6L V6 (LGX), the XT6's GM 9T65 9-speed automatic transmission exhibits shuddering during light throttle acceleration between 25-50 mph, similar to driving over rumble strips. The torque converter clutch wears prematurely, contaminating the transmission fluid.

On the 2020-2025 Cadillac XT6 2.0L Turbo I4 (LSY), gM bulletin 21-NA-240 describes an engine oil leak that may result from the amount of sealant at the LSY camshaft-carrier gasket. Oil can appear to originate at another front-engine joint. The bulletin directs technicians to locate the actual leak before selecting a repair; it does not establish that every equipped XT6 has this condition.

On the 2021-2023 Cadillac XT6, owners of 2021-2023 Cadillac XT6 vehicles built before the bulletin's VIN breakpoint report a grinding or groaning noise from the front brakes on the first few stops, particularly after the vehicle has sat overnight. It may feel like the ABS is active even though it is not. GM bulletin 21-NA-142 (current revision January 2025) says the cause may be the front disc brake pad material and has technicians check the pad stamp (GM9130 or GM9140). The same bulletin also covers the Buick Enclave, Cadillac XT5, Chevrolet Blazer and Traverse, and GMC Acadia within listed VIN ranges.