18
Operation
Looking up the Diagnostic Trouble Codes
To find out the meaning of an unknown trouble code, select “DTC Lookup”
in the main menu. In the following menu enter the trouble code into the
unit. To do so follow the instructions displayed at the bottom of the
window. Confirm your entry with ENTER. The meaning of the trouble code
is either displayed immediately or the trouble code is identified as
manufacturer-specific. In this case pressing ENTER again will call up a list
of vehicle manufacturers. Select the manufacturer of the vehicle and press
ENTER again. The meaning of the trouble code is displayed.
If the manufacturer is not on the list please look up the meaning of the
trouble code in the technical literature.
Erasing the Diagnostic Trouble Codes
To erase the trouble codes select “Erase Codes” in the diagnostic menu.
To erase the codes follow the displayed instructions. Confirm with ENTER,
the BACK Button will bring you back to the previous menu without erasing
the codes.
After erasing the trouble codes retrieve the codes again to make sure all
repairs were successful and all codes were erased successfully.
I/M Readiness Status
The I/M Readiness function is used to check the operations of the
Emission System on OBD
II
compliant vehicles. An I/M Readiness Status
result of “NO” does not necessarily indicate that the vehicle being tested
will fail the state I/M inspection.
The OBD II readiness monitors are an important part of a vehicle’s OBD
system. They run periodic tests on specific systems and components to
ensure they are functioning within allowable limits. Not all monitors are
present in all vehicles and the exact specification depends on the
emissions control strategy of the manufacturer of the vehicle.
Some components of the vehicle are monitored continuously while the
engine is operating; their status is always listed as ready:
MISFIRE
—Misfire monitoring
FUEL
—Fuel System Monitoring
CCM
—Comprehensive Components Monitoring
Do not erase the codes before the system has been checked
and repaired.
