Craftsman 14063 manual Not all vehicles support all fifteen Monitors

Onboard Diagnostics

COMPUTER ENGINE CONTROLS

„Powertrain Control Module (PCM) - The PCM is the OBD2 accepted term for the vehicle’s “on-board computer.” In addition to controlling the engine management and emissions systems, the PCM also participates in controlling the powertrain (transmission) operation. Most PCMs also have the ability to communicate with other computers on the vehicle (ABS, ride control, body, etc.).

„Monitor - Monitors are “diagnostic routines” programmed into the PCM. The PCM utilizes these programs to run diagnostic tests, and to monitor operation of the vehicle’s emissions-related components or systems to ensure they are operating correctly and within the vehicle’s manufacturer specifications. Currently, up to fifteen Monitors are used in OBD2 systems. Additional Monitors will be added as the OBD2 system is further developed.

Not all vehicles support all fifteen Monitors.

„Enabling Criteria - Each Monitor is designed to test and monitor the operation of a specific part of the vehicle’s emissions system (EGR system, oxygen sensor, catalytic converter, etc.). A specific set of “conditions” or “driving procedures” must be met before the computer can command a Monitor to run tests on its related system. These “conditions” are known as “Enabling Criteria.” The requirements and procedures vary for each Monitor. Some Monitors only require the ignition key to be turned “On” for them to run and complete their diagnostic testing. Others may require a set of complex procedures, such as, starting the vehicle when cold, bringing it to operating temperature, and driving the vehicle under specific conditions before the Monitor can run and complete its diagnostic testing.

„Monitor Has/Has Not Run - The terms “Monitor has run” or “Monitor has not run” are used throughout this manual. “Monitor has run,” means the PCM has commanded a particular Monitor to perform the required diagnostic testing on a system to ensure the system is operating correctly (within factory specifications). The term “Monitor has not run” means the PCM has not yet commanded a particular Monitor to perform diagnostic testing on its associated part of the emissions system.

„Trip - A Trip for a particular Monitor requires that the vehicle is being driven in such a way that all the required “Enabling Criteria” for the Monitor to run and complete its diagnostic testing are met. The “Trip Drive Cycle” for a particular Monitor begins when the ignition key is turned “On.” It is successfully completed when all the “Enabling Criteria” for the Monitor to run and complete its diagnostic testing are met by the time the ignition key is turned “Off.” Since each of the eleven monitors is designed to run diagnostics and testing on a different part of the engine or emissions system, the “Trip Drive Cycle” needed for each individual Monitor to run and complete varies.

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