Craftsman 3130eSC Manual De Usuario

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Onboard Diagnostics 
 
 
OBD2 MONITORS 
 
 
FixAssist
®
 19 
 
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If the conditions that caused the MIL to light are no longer present 
for the next three trips in a row, the computer automatically turns the 
MIL “Off” if no other emissions-related faults are present. However, 
the DTCs remain in the computer’s memory as a history code for 40 
warm-up cycles (80 warm-up cycles for fuel and misfire faults). The 
DTCs are automatically erased if the fault that caused them to be 
set is not detected again during that period. 
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Misfire and fuel system faults require three trips with “similar 
conditions” before the MIL is turned “Off.” These are trips where the 
engine load, RPM and temperature are similar to the conditions 
present when the fault was first found. 
After the MIL has been turned off, DTCs and Freeze Frame 
data stay in the computer’s memory. 
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Erasing the DTCs from the computer’s memory can also turn off the 
MIL. See ERASING DIAGNOSTIC TROUBLE CODES (DTCs) on 
page 52, before erasing codes from the computer’s memory. If a 
Diagnostic Tool or Scan Tool is used to erase the codes, Freeze 
Frame data will also be erased. 
OBD2 MONITORS 
To ensure the correct operation of the various emissions-related 
components and systems, a diagnostic program was developed and 
installed in the vehicle’s on-board computer. The program has several 
procedures and diagnostic strategies. Each procedure or diagnostic 
strategy is made to monitor the operation of, and run diagnostic tests on, 
a specific emissions-related component or system. These tests ensure 
the system is running correctly and is within the manufacturer’s 
specifications. On OBD2 systems, these procedures and diagnostic 
strategies are called “Monitors.” 
Currently, fifteen Monitors are supported by OBD2 systems. Additional 
monitors may be added as a result of Government regulations as the 
OBD2 system grows and matures. Not all vehicles support all fifteen 
Monitors. Additionally, some Monitors are supported by “spark ignition” 
vehicles only, while others are supported by “compression ignition” 
vehicles only. 
Monitor operation is either “Continuous” or “Non-Continuous,” 
depending on the specific monitor.  
Continuous Monitors 
Three of these Monitors are designed to constantly monitor their 
associated components and/or systems for proper operation. 
Continuous Monitors run constantly when the engine is running. The 
Continuous Monitors are: 
 Comprehensive Component Monitor (CCM) 
 Misfire Monitor 
 Fuel System Monitor