How many monitors must pass on an On-Board Diagnostics (OBD) test?

In the context of an On-Board Diagnostics (OBD) test, the requirement is that all monitors must pass for the vehicle to be considered compliant with emissions regulations. This is because OBD systems are designed to continuously monitor the performance of various emissions-related components and systems.

All monitors include checks for the engine, fuel system, catalytic converter, Oxygen sensors, and other components. If any one of these monitors fails, it indicates that there may be a problem with the emissions system, which could lead to increased pollution. Therefore, for a vehicle to be deemed roadworthy and to pass the emissions test, it is essential that every single monitor reports a passing status.

Other options are not sufficient because they suggest that only a subset of the monitors needs to pass for compliance, which does not align with the stringent standards set forth in emissions testing protocols. These standards are in place to ensure that all aspects of the emissions systems function properly, thus protecting both the environment and public health.