Instruction Manual

CAN OBD2 43

Emissions tests vary depending on the geographic or region-

al area in which the vehicle is registered. If the vehicle is reg-

istered in a highly urbanized area, the I/M 240 is probably the

type of test required. If the vehicle is registered in a rural area,

the stricter “dynamometer type” test may not be required.

I/M Readiness Monitors

I/M Readiness shows whether the various emissions-related systems

on the vehicle are operating properly and are ready for Inspection and

Maintenance testing.

State and Federal Governments enacted Regulations, Procedures and

Emission Standards to ensure that all emissions-related components

and systems are continuously or periodically monitored, tested and

diagnosed whenever the vehicle is in operation. It also requires vehi-

cle manufacturers to automatically detect and report any problems or

faults that may increase the vehicle's emissions to an unacceptable level.

The vehicle's emissions control system consists of several compo-

nents or sub-systems (Oxygen Sensor, Catalytic Converter, EGR, Fuel

System, etc.) that aid in reducing vehicle emissions.

To have an efficient Vehicle Emission Control System, all the emis-

sions-related components and systems must work correctly whenever

the vehicle is in operation.

To comply with State and Federal Government regulations, vehicle

manufacturers designed a series of special computer programs called

"Monitors" that are programmed into the vehicle's computer. Each of

these Monitors is specifically designed to run tests and diagnostics on

a specific emissions-related component or system (Oxygen Sensor,

Catalytic Converter, EGR Valve, Fuel System, etc.) to ensure their

proper operation. Currently, there are a maximum of eleven Monitors

available for use.

Each Monitor has a specific function to test

and diagnose only its designated emissions-

related component or system. The names of the

Monitors (Oxygen Sensor Monitor, Catalyst

Monitor, EGR Monitor, Misfire Monitor, etc.)

describe which component or system each Monitor

is designed to test and diagnose.

Using the Code Reader

I/M READINESS TESTING

To learn more about Emissions Inspection and Maintenance

(I/M) Readiness Monitors, see OBD 2 MONITORS on page 23.