2021 GMC Acadia Reliability Report

A "Steering Assist Is Reduced" warning dominates. It usually arrives with a temperature gauge stuck on cold, loss of heat or AC, and a loud cooling fan that keeps running after the engine is off. Owners report that disconnecting the battery clears it temporarily. Diagnoses point to a failed thermostat or coolant temperature sensor and module communication codes. Some owners have the problem return several times. Less often, the steering turns suddenly stiff on the highway, the car pulls to one side, or a stall brings on the warning.

Front brakes grind and squeal, usually when cold or after sitting overnight, even on low-mileage cars, and repeat dealer visits often end without a fix. More serious reports describe sudden loss of braking. Causes include front brake hoses rubbing against the CV axle or drive shaft until they leak or tear, a failed vacuum pump, and a leaking ABS modulator. Pedals that sink to the floor and fluid on the driveway are warning signs. Other complaints describe automatic braking activating for no reason and the parking brake engaging while driving. One complaint involves a crash.

Thermostat failures lead the list. They set codes, trigger a reduced steering assist message, and leave the cooling fan running after shutoff. Some owners also need a radiator or oil cooler, with one corroded radiator leaking at around 32,175 miles. A loud buzz or rattle from the front muffler or resonator, felt through the passenger floor around 2,000 to 2,500 rpm, is also common, and owners cite a service bulletin for it. Catalytic converters crack and get replaced repeatedly. Crankcase moisture codes and fuel pump module stalls round out the reports.

A "Service Safety Restraint System" warning comes on and goes off at random while driving, sometimes within days of delivery. Dealers replace the airbag control module or work on seat belt tensioners, but the light often comes back, and repairs can take two weeks. Repeat failures appear between 3,741 and 16,000 miles. A warning light can mean the airbags may not deploy. One crash-related complaint with an injury describes the front airbags deploying in a low-speed parking lot impact and breaking the driver's arm.

Loss of power while driving, followed by a stall and a no-restart, describes every report. The fault is traced to the fuel pump control module or fuel pump module, sometimes with code P023F. Some cars give no warning, while others light the check engine lamp first. Failures happen in traffic and at highway speed, including one near-miss with a tractor trailer. Mileage in one report is 36,970. Owners also report the replacement part on backorder, which keeps cars off the road.

Few reports, but they vary. One crash-related complaint describes the accelerator pedal sticking to the floor while reversing, putting the car into a garage wall at about 2,500 miles. Another describes the transmission slipping near 8900 miles, with dark, muddy fluid returning within 100 miles of a fluid change and the dealer planning to take the transmission apart. A third describes brake trouble after a vacuum pump failure.

Power liftgate supports fail. In one report a support arm pops off and the gate falls onto the owner while loading cargo, causing an injury. In another, the driver's side liftgate spring breaks while the gate closes at about 15,000 miles. Water leaking into the cargo area is also reported. There are only two complaints, but the failure mode is a direct injury risk.