Some 2013-2017 GM models may have a lack of performance in excessively hot and sustained ambient temperatures over 100° F (37.7° C) due to vapor buildup in the fuel feed line. DTCs P2635 (Fuel Pump Flow Performance) and P018B (Fuel Pressure Sensor Performance) may be set.
If the vehicle has not had a fuel pump replaced, refer to #PIP5411 for additional diagnostic information. It may be necessary to replace the fuel tank fuel pump module assembly. (Fig. 10)
If the vehicle has had a fuel pump replaced, advise owners to use fuels with an octane rating higher than 91 and to refrain from periods of extending idling, if possible.
– Thanks to Richard Renshaw