Most of the times no, but each case and state is different (I'm in California, not Hawaii), you can all the office and ask the general question (get the name of the person you talked to).
Take Note: Common Sense and this environment (the internet) require me to remind everyone that this answer isn't legal advice, and shouldn't be relied upon. Remember-every state has different laws, rules and regulations and each person's situation is fact specific, and it is impossible to evaluate a legal problem without a thorough evaluation and review of all the facts and documents at issue, including potential investigation. By answering or posting information here, it doesn't create an attorney-client relationship.
I am not admitted to practice in Hawaii, but in the states where I practice, probation officers have wide latitude to inquire into your activities and recommend that the probation be revoked in cases of illegal behavior. Most probation officers have significant discretion and a probationer who over-reports his or her issues is more likely to get a break than one who fails to report.
Probation officers see such a parade of knuckleheads and idiotic behavior that a probationer who calls to report a minor traffic violation will be seen as someone who is on a good course for rehabilitation.
As a part-time Magistrate who sentences people to probation every week and also is required to revoke probation when defendants violate the conditions, I can say that being forthcoming about a minor issue is a sign of credibility and one that I would reward rather than punish.