Was counseled in writing for taking more then 5 minutes to perform a Pre-Trip inspection on a school bus.

If you have an employee handbook, or some other set of policies and procedures that was issued to you (or which you can get a copy of, without creating a problem), I'd recommend that you take that, and whatever else you have in writing, to an employment lawyer in your area, if you think that this might be the start of an ongoing problem.  One place to look for a qualified attorney would be our website, http://attorneypages.com

Unless you have a contract, your employment is "at will," which means you can be fired for no reason at all.  Most courts interpret that to mean that anything less than firing, like this on-the-record counseling, also can be done without needing a reason.  The exceptions are limited, and mostly deal with illegal reasons for employment decisions, such as racial discrimination, or retaliation for the use of legal rights such as workers compensation.

In very limited cases, employee handbooks or company procedures can be used as if they were employment contracts, for these purposes.  It's typically an uphill battle to succeed at that, even for experienced attorneys.