LAUNCH                                                                 
CReader Series English User’s Manual
 
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Figure 2-2 
2.4 OBD II Readiness Monitors 
An important part of a vehicle’s OBD II system is the Readiness Monitors, which 
are  indicators  used  to  find  out  if  all  of  the  emissions  components  have  been 
evaluated  by  the  OBD  II  system.  They  are  running  periodic  tests  on  specific 
systems  and  components  to  ensure  that  they  are  performing  within  allowable 
limits. 
Currently, there are eleven OBD II Readiness Monitors (or I/M Monitors) defined 
by  the  U.S.  Environmental  Protection  Agency  (EPA).  Not  all  monitors  are 
supported  in  every  vehicles  and  the  exact  number  of  monitors  in  any  vehicle 
depends on the motor vehicle manufacturer’s emissions control strategy. 
Continuous  Monitors  --  Some  of  the  vehicle  components  or  systems  are 
continuously tested by the vehicle’s OBD II system, while others are tested only 
under  specific  vehicle  operating  conditions.  The  continuously  monitored 
components listed below are always ready: 
1. Misfire 
2. Fuel System 
3. Comprehensive Components (CCM) 
Once  the  vehicle  is  running,  the  OBD  II  system  is  continuously  checking  the 
above components, monitoring key engine sensors, watching for engine misfire, 
and monitoring fuel demands.   
Non-Continuous Monitors -- Unlike the continuous monitors, many emissions and