On-Board Diagnostics II System

WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.

On-Board Diagnostics II (OBD-II) is a government mandated on-vehicle emission monitoring and control system. Some of the criteria necessary for an OBD-II system is as follows:

Exhaust emissions must remain within specified threshold.
Catalyst efficiency is monitored.
All emission related systems are monitored by PCM.
When a fault in a system or component occurs, DTC will set and MIL will illuminate.
DTCs are numbered using standardized method for all manufacturers.
Data Link Connectors (DLCs) are standardized for all OBD-II vehicles for use with generic OBD-II scan tools.