What's New Products Where To Buy Customer Service Media Tool Updates
FAQ: GM Code Scanner CP9001
How do I know if my vehicle is OBD I or OBD II on-board diagnostics equipped?
What is the difference between OBD I and OBD II cars?
What is OBD?
What are DLCs?
Common Chrysler OBD II (P1) Enhanced Codes
Will the Actron Code Scanners and/or Scan Tools retrieve Anti-Lock Brake or Airbag codes?
Do I need adapters for different vehicles?
What are I/M Monitors?
What is MIL Status?
What are Pending Codes?
What is the Erase Codes function?
Which Actron Code Scanners and/or Scan Tools work on 1994 & 1995 GM vehicles?
What are PIDs?
What are DTCs?
What are Enhanced OBD II codes?
Common Generic OBD II (P0) Codes
Common GM OBD II (P1) Enhanced Codes
  What are I/M Monitors?
  I/M (Inspection & Maintenance) Monitors test the operation of emission-related systems or components and detect out-of-range values. The vehicle may have to be operated under certain conditions to complete an I/M Monitor test. Currently, there are eleven I/M Monitors defined by the U.S. Environmental Protection Agency (EPA). Not all monitors are supported by all vehicles.
These I/M Monitors are:

I/M MonitorDefinition
Fuel SysFuel System
ComprehensComprehensive Components
Heated CatHeated Catalyst
Evap SysEvaporative System
Sec AirSecondary AIR
A/C RefrigAir Conditioning Refrigerant
O2 SensorOxygen Sensor
HO2 SensorHeated Oxygen Sensor
EGR SysExhaust Gas Recirculation System

  • A monitor status of 'Ready' means that the required driving conditions for that monitor have been met and it passed.
  • A monitor status of 'Not Ready' means that the required driving conditions for that monitor have not been completed or it did not pass.
  • A monitor status of 'N/A' means that the vehicle does not support that monitor.

Several state emission check programs require all I/M Monitors to be in a status of Ready or N/A in order for the vehicle to pass. You can use Actron Code Scanners or Scan Tools to find out if your vehicle is ready before going to your state emission test.
Sitemap   Terms & Conditions   Privacy   Product Registration   Contact

© Bosch Automotive Service Solutions LLC