I recently bought a used 2018 Tahoe with 40,000 miles. Randomly, after my car was running for 2 hours straight, the electronics began cutting off briefly while driving. It can happen when braking going over 70 mph, or when turning on the bright lights manually at any speed. Sometimes the lights just dim, but if the they cut off completely, the "Stabilitrack" service message pops up. After the car does this and is turned off, more often then not it is stone cold dead and has to be jumped to turn back on. Nothing extra like a phone is plugged in causing power to be drawn away from the battery. It only seems to happen after my car has been running for over an hour continuously. Short 10 minute drives to the store and back have no issue.

Both my husband and my mechanic have checked all the connections and nothing is loose. My battery is tested perfect and the only thing that comes up when put on the computer is low voltage. My engine light is not on. Has anyone had this issue and gotten it fixed permanently? Please help before I decide to leave Chevy all together.

 

have your alternator load tested.

 

My 2004 Suburban had problem with no power on starting. Problem was side battery terminal connectors - they seem to be tight, but turned out the connector bolt threads were stripped and cable was not making good connection. Replaced them with new connectors ($6 at Advanced Auto) and problem went away. Yours being a 2018 seems too new to have this problem unless an overzealous installer torqued too hard on the connectors and stripped the threads.

 

Did you find a fix? My 2018 Tahoe is doing the same thing and also will **** the vehicle off for a split second. Then come back on and drive fine until i hit the brakes again or use a turn signal.