2025 Cadillac XT4 Reliability Report

Telematics module failure is the main problem. When it fails, OnStar stops working, emergency calling becomes unreliable, built-in maps fail, and OnStar cannot find the car's location. In one case the module drained the battery until the car would not start. The bigger issue is the part shortage. Dealers report no supply and no backorder date, so cars wait weeks or sit at the dealer unrepaired. Separately, a car started on its own after being parked and shut off, around 17,000 miles. A computer reset did not fix it, and the problem came back.

Sudden transmission disengagement at highway speed is the most serious report. The car loses power around 60 mph in moving traffic and has to be towed to a dealer, which creates a real crash risk. Transmission fluid leaks also appear, starting soon after purchase. The same reports mention OnStar trouble, unreliable advisor contact in emergencies, apps and maps that work only some of the time, and service-required errors for lane keep assist and side detection. Dealers say the OnStar and map faults are an ongoing issue with many complaints.

Braking can fail outright. A brake failure warning appears, or the pedal sinks to the floor with the check engine and brake warning lights on. Either way, the car loses most of its stopping power, and some owners have it towed. Dealers trace the fault to the brake control module and update it or repair it under warranty. Even so, the failure returns in some cases. Related module errors also show up as stored fault codes, and in one case they blocked camera recalibration after a windshield replacement. One report describes the wheels locking up while backing up.