Don't reset the OBD ll codes in a Jeep Liberty CRD without first addressing the root of the engine trouble, unless you're convinced the code was stored in error. Resetting the codes is relatively easy. A hand-held scanning device designed to interpret and clear OBD ll codes, rather than the older OBD l codes, is your best bet for the job, although other methods also work. Scanners begin at around £13 as of 2010, with more sophisticated models costing quite a bit more.
Locate the ALDL (Assembly Line Diagnostic Link) under the dash near the steering column. It's a small 12- to 16-point electrical port, sometimes with a plastic cover on top.
Connect the OBD II scanner to the ALDL. Turn the ignition key to the "On" position.
Follow the prompts on the scanner to retrieve stored error codes. Select the option to reset the codes.
Wait for the codes to clear themselves. Chrysler vehicles automatically reset the error codes after the engine has been run successfully 40 times.
Crank the ignition on the Jeep. Drive forward a few feet, then drive in reverse a few feet. Repeat this three times, then turn the engine off. Crank it again and check the dash panel. The OBD II code should be cleared.
Disconnect the battery for a few minutes to manually reset the OBD II code. Disconnecting the battery also clears other electrical components, such as the clock, radio settings and saved seat settings.
Take your Jeep to an auto parts store, such as Advanced Auto or Auto Zone, to have the OBD II code reset free of charge.