Equus 3150 - ABS/SRS + OBD2 Diagnostic Tool - Manual (Page 59)

Using the Code Reader
I/M READINESS TESTING
OBD2 57
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.
Emissions Inspection and Maintenance (I/M) Readiness
Monitor Status Information
I/M Readiness Monitor Status shows which of the vehicle's Monitors
have run and completed their diagnosis and testing, and which ones
have not yet run and completed testing and diagnosis of their
designated sections of the vehicle's emissions system.
„ If a Monitor was able to meet all the conditions required to enable it
to perform the self-diagnosis and testing of its assigned engine
system, it means the monitor "HAS RUN.”
„ If a Monitor has not yet met all the conditions required for it to
perform the self-diagnosis and testing of its assigned engine system;
it means the Monitor "HAS NOT RUN.”
The Monitor Run/Not Run status does not show whether
or not a problem exists in a system. Monitor status only
indicates whether a particular Monitor has or has not run
and performed the self-diagnosis and testing of its
associated system.
Performing I/M Readiness Quick Check
When a vehicle first comes from the factory, all Monitors
indicate a “HAVE RUN” status. This indicates that all Monitors
have run and completed their diagnostic testing. The “HAVE
RUN” status remains in the computer's memory, unless the
Diagnostic Trouble Codes are erased or the vehicle's
computer memory is cleared.
To learn more about Emissions Inspection and Maintenance
(I/M) Readiness Monitors, see OBD2 MONITORS on page 22.