Cadillac XT6 Fault Codes

About the XT6

The XT6 entered the market as the largest crossover offering in the Cadillac lineup in 2019. This can be seen by its name ‘XT’ standing for Crossover Touring, while the ‘6’ indicates that it sits above both the XT4 and XT5.

Since its release, there has been only a single generation to hit the markets. These include North America, China, Russia, and Japan.

The XT6 goes up against a number of notable luxury crossover models. Some of its main competitors include the Genesis GV80, Porsche Cayenne, BMW X5, and Volvo XC90.

The model has faced a number of misfire issues, causing a technical service bulletin (TSB) to be released addressing the issue.

This is typically shown by fault code P0300, which indicates that multiple random misfires have occurred. It has been noted by owners that this commonly happens during a cold start.

According to the TSB, this can be caused by cylinder block porosity, which will require a technician to diagnose. Unfortunately, this may require the entire engine to be replaced.

Another common issue for the model is P0621, which is logged when the generator lamp L control circuit is malfunctioning.

The potential causes of this issue can be fairly extensive. However, a failing alternator or battery are some of the most commonly reported by owners.

Fault code P0455 is another problem that owners have reported fairly commonly. This code indicates that there is a leak from the evaporative emissions control (EVAP) system. Unlike the other two codes, this is a fairly mild problem in terms of seriousness.

In most cases, this code is caused simply by a loose gas cap. It is also possible that the gas cap is defective and needs replacing.