On one morning w/20 something temperature, Tah started and immediately shut down. When restarted, multiple malfunction lights were lit: engine, ABS/brake, steering column, traction control, etc. Reached Onstar for advice to see if Tah was drive-able, but only got confirmation of system malfunctions and offered roadside assistance but declined since at home and would call back if needed. About an hour later and several restarts, all malfunction lights finally cleared except engine light, which stayed on for another day or so. Tah drove okay during engine light on.