Using the Diagnostic Tool
I/M READINESS TESTING
46 OBD2
The Diagnostic Tool allows you to retrieve Monitor/System Status
Information to help you determine if the vehicle is ready for an
Emissions Test (Smog Check). In addition to retrieving Diagnostic
Trouble Codes, the Diagnostic Tool also retrieves Monitor Run/Not Run
status. This information is very important since different areas of the
state/country have different emissions laws and regulations concerning
Monitor Run/Not Run status.
Before an Emissions Test (Smog Check) can be performed, your
vehicle must meet certain rules, requirements and procedures legislated
by the Federal and state (country) governments where you live.
1. In most areas, one of the requirements that must be met before a
vehicle is allowed to be Emissions Tested (Smog Checked) is that
the vehicle does not have any Diagnostic Trouble Codes present
(with the exception of PENDING Diagnostic Trouble Codes).
2. In addition to the requirement that no Diagnostic Trouble Codes be
present, some areas also require that all the Monitors that a
particular vehicle supports indicate a "Has Run" status condition
before an Emissions Check may be performed.
3. Other areas may only require that some (but not all) Monitors
indicate a "Has Run" status before an Emissions Test (Smog Check)
may be performed.
Monitors with a "Has Run" status indicate that all the
required conditions they needed to perform diagnosis and
testing of their assigned engine area (system) have been
met, and all diagnostic testing has completed successfully.
Monitors with a "Has Not Run" status have not yet met the
conditions they need to perform diagnosis and testing of
their assigned engine area (system), and have not been
able to perform diagnostic testing on that system.
The green, yellow and red LEDs provide a quick way to help you
determine if a vehicle is ready for an Emissions Test (Smog Check).
Follow the instructions below to perform the Quick Check.
Perform the
CODE RETRIEVAL PROCEDURE as described on page
37, then interpret the LED indications as follows:
Interpreting I/M Readiness Test Results
1. GREEN LED - Indicates that all engine
systems are "OK" and operating
normally (all Monitors supported by the
vehicle have run and performed their
self-diagnostic testing). The vehicle is
ready for an Emissions Test (Smog
Check), and there is a good possibility
that it can be certified.
2. YELLOW LED - Determine from the
CODE RETRIEVAL
PROCEDURE (page
37) which of the two possible conditions is
causing the yellow LED to light.
