Which action is NOT allowed under the federal odometer law?

Operating a vehicle while knowing the odometer is disconnected is not allowed under the federal odometer law because it constitutes a violation of regulations aimed at preventing odometer fraud. The law is designed to protect consumers by ensuring that they receive accurate information regarding a vehicle's mileage. When a driver operates a vehicle with a disconnected odometer, there is no reliable way to track the actual miles driven; this can mislead potential buyers about the vehicle's condition, wear, and value.

In contrast, regular maintenance of the odometer, disclosure of the odometer reading during a sale, and resetting the odometer for lawful repairs are practices permitted under the federal law, as they contribute to transparency and ensure that all actions taken regarding the odometer are within legal and ethical boundaries. Regular maintenance ensures the odometer functions correctly, while disclosure is required to inform buyers about the vehicle's history, and resetting can be done under specific conditions, such as when it is necessary for repairs, as long as it is done in compliance with regulations.