Diesel On Board Diagnostics (OBD) Monitors: Notes

This information provides a general description of each OBD monitor. In these descriptions, the monitor strategy, hardware, testing requirements, and methods are presented together to provide an overall understanding of each monitor operation.

Each illustration depicts the PCM as the main focus with the primary inputs and outputs for each monitor. The numbers 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 carrying out the tests and the systems being tested. The comprehensive component monitor (CCM) 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 DTCs.

These monitor descriptions are intended as general information only.