What is a common result of a malfunctioning OBD system?

A common result of a malfunctioning On-Board Diagnostics (OBD) system is the illumination of the check engine light. The OBD system is designed to monitor various performance components and systems within a vehicle, including emissions controls. When the system detects an issue, such as a failure in emissions-related components like the catalytic converter, oxygen sensors, or fuel injectors, it triggers the check engine light as a warning to the driver that there is a problem needing attention. This light serves as a prompt for the driver to have the vehicle inspected for diagnostic trouble codes that can pinpoint the exact issue.

The other options represent different systems within the vehicle that do not directly relate to emissions monitoring and would not typically be activated by OBD malfunctions. For example, the airbag light specifically indicates issues with the safety systems; fluctuations in the battery gauge relate to the electrical system; and oil pressure warnings are tied to engine lubrication problems. Each of these lights serves a distinct purpose and is not a direct result of a fault in the OBD system itself.