On Board Diagnostics System Monitors: Overview

The OBD II monitors described in this section provide a general description of each monitor. In these descriptions, the monitor strategy, hardware, testing requirements and methods are tied together to provide an overall understanding of each monitor operation.

NOTE: An illustration for each monitor is also provided to aid in the description. These illustrations should be used as typical examples and are not intended to represent all the possible configurations.

Each illustration represents the Powertrain Control Module (PCM) as the main focus with the primary inputs and outputs for each monitor. The icons to the left of the PCM represent the inputs used by each of the monitor strategies to enable or activate the monitor. The components and subsystems to the right of the PCM represent the hardware and signals used while performing the tests and the systems being tested. The Comprehensive Component Monitor illustration has numerous components and signals involved and is shown generically. When referring to the illustrations, match the numbers to the corresponding numbers in the monitor descriptions for a better comprehension of the monitor and associated Diagnostic Trouble Codes (DTCs).

These monitor descriptions are intended as general information only. Refer to Drive Cycles for detailed testing instructions for each monitor.

OBD-II Monitors Icon Illustrations:

These icons are used in the illustrations of the OBD-II monitors.