A specific series of driving maneuvers is sometimes required to allow a vehicle’s onboard diagnostic system to complete emissions-related self-tests. This process, often prescribed by manufacturers, involves variations in speed, acceleration, deceleration, and engine idling time. For example, this might include a period of highway driving at a steady speed followed by city driving with frequent stops and starts.
Completing these prescribed driving patterns enables the vehicle’s computer to monitor various emissions components and ensure they are functioning correctly. This is essential for passing emissions tests and maintaining optimal engine performance and fuel efficiency. Historically, these procedures became necessary with the introduction of more sophisticated onboard diagnostics in the late 20th century to meet increasingly stringent emissions regulations. This process can be crucial for identifying potential problems and ensuring compliance with environmental standards.
