What does a failing OBD readiness monitor indicate?

A failing OBD readiness monitor indicates that the vehicle's onboard diagnostic (OBD) system has not completed the necessary self-diagnosis of its emission systems. This means that the vehicle's computer hasn't performed all the required checks to determine whether the emissions-related components are functioning correctly.

When a vehicle is running and operating properly, the OBD system continuously monitors the performance of the emissions control systems. If the readiness monitors are showing a failure, it suggests that the vehicle has either recently had its battery disconnected, has not been driven under the right conditions to complete the diagnostic tests, or that there are issues present that need to be addressed.

This readiness monitor is essential for ensuring compliance with emissions regulations, as failing to complete these checks may lead to increased emissions or operational inefficiencies. The other choices do not accurately reflect the implications of a failing readiness monitor, as they focus on unrelated vehicle maintenance issues rather than the diagnostic processes associated with emissions monitoring.