OBD2 Monitors

Purpose

To explain the definition of OBD2 monitors for your vehicle.

What are OBD2 Monitors?

To ensure the correct operation of the various emissions-related components and systems, a diagnostic program was developed and installed inside the vehicle’s onboard computer. This diagnostic program has several procedures and diagnostic strategies. Each procedure or diagnostic strategy is made to monitor the operation of, and run diagnostic tests on, a specific emissions-related component or system. These tests ensure that the system is running correctly and is within the manufacturer’s specifications. On OBD2 systems, these procedures and diagnostic strategies are called 'Monitors'.

Currently, only fifteen Monitors are supported by OBD2 systems. Additional monitors may be added as a result of Government regulations as the OBD2 system grows and matures. Not all vehicles support all fifteen Monitors. Additionally, some Monitors are supported by 'spark ignition' vehicles only, while others are supported by 'compression ignition' vehicles only.

Monitor operation is either 'Continuous' or 'Non-Continuous', depending on the specific monitor.