Anti Lock lamp 95 Chevy truck

[Boatwrench]

A guy in my office has a 95 4WD Chevrolet 1/2t P/U. the Antilock Brake light on the dash stays on. My best guess is that it is like a check engine light and indicates a possible problem with the system. He will be driving home this weekend (750 miles one way) and is concerned.

Any thoughts of why this lamp remains illuminated?

Thanks,
Tom