Which statement about the two-part fuel cap test is true?

• A. It is optional
• B. It is performed only visually
• C. It requires both functional and visual inspections
• D. It is performed only if the MIL is on

Answer: (C)

The test is about ensuring the fuel system’s evaporative emissions seal is intact. You must do both parts: inspect the cap visually for damage, cracks, a missing or damaged gasket, or incorrect cap type, and perform a functional check to verify the seal actually holds pressure or vacuum and doesn’t leak. Visual alone can miss leaks that only show up when the system is pressurized or evacuated, so the functional check is essential. The MIL light status doesn’t determine whether the test is required, so it’s performed as part of the standard inspection regardless of illumination. That’s why the best answer is that it requires both functional and visual inspections.