2014 Camero electrical/engine issues

At 12,900 miles had to replace rely starter and repair wiring to PCM
because car would not restart immediately after being driven.  At 20,900
miles car died unexpectedly as driver stopped at a red light and would not
restart. Information message said "low engine:" "service traction control:
Owner was told an electrical sensor had come loose/rubbed against a belt,
and that sensor and entire wiring harness had to be replaced. Is this an
issue of poor service on the original problem or a defect in the engine
design?