One preclinical remediation is not going to take you out of the running for academic IM programs, but obviously would be good to dissect why it happened and make improvements so you can do well on future exams.
Remediating a class and everything else looks good? I would not think so since it's preclinical. If it's coupled with other remediations, or a borderline STEP 1/2 then it's difficult to overlook as an isolated thing.