Hey, That’s Normal
GM notes that 2013-2017 vehicles equipped with GDI engines (gasoline direct injection) may exhibit stalling, hesitation and lack of performance in high ambient temperatures.
In ambient temperatures of 100 degrees Fahrenheit or higher, DTCs P2635 and/or P018B may set. The cause: excessively high and sustained ambient temperatures over 100 degrees F (“mainly in TX, AZ, UT, NV, CA and NM) may cause vapor buildup in the fuel feed line.
If the pump has been replaced and the problem exists, customers can be advised to utilize fuels with octane levels greater than 91, to refrain from extended idle periods, and if possible, to park vehicles in a covered garage. “Replacing the fuel pump will not repair the concern.”