Table 1 shows ten common electrical system related problems of the 2015 GMC Sierra 1500. The number one most common problem is related to the electrical system (84 problems). The second most common problem is related to the integrated trailer brake control (two problems).
For no apparent reason the truck goes into “low power mode” and gives off code p2138 often happens around 30-35 mph. Have had it happen to me also around 45 mph also. I have replaced sensors and parts to which a month or so goes by and it happens again. Read details...
The contact owns a 2015 GMC Sierra 1500. The contact stated that while driving at various speeds, the warning message "service trailer brake system" was displayed along with an audible warning chime although no trailer was being towed. Read details...
Has had an issue with accessories flashing off and back on. Reported it to a GMC dealer and they were unable to duplicate but said that the battery was bad and most likely what was causing it. It did fine for a while then began doing it again. Read details...