Craftsman 3130eSC Manual De Usuario

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Onboard Diagnostics 
 
 
COMPUTER ENGINE CONTROLS 
 
 
FixAssist
®
 15 
 
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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. 
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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. 
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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 fifteen 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.