2008 Jeep Liberty Owner's Manual - Page 400

400 MAINTAINING YOUR VEHICLE Loose Fuel Filler Cap Message If the vehicle diagnostic system determines that the fuel filler cap in loose, improperly installed, or damaged, a "gASCAP" message will display in the instrument cluster. Tighten the gas cap until a "clicking" sound is heard. This is an indication that the gas cap is properly tightened. Press the trip odometer reset button to turn off the message. If the problem persists, the message will appear the next time the vehicle is started. This might indicate a damaged cap. If the problem is detected twice in a row, the system will turn on the Malfunction Indicator Light (MIL). Resolving the problem will turn the MIL light off. EMISSIONS INSPECTION AND MAINTENANCE PROGRAMS In some localities, it may be a legal requirement to pass an inspection of your vehicle's emissions control system. Failure to pass could prevent vehicle registration. For states, which have an I/M (Inspection and Maintenance) requirement, this check verifies the following: the MIL (Malfunction Indicator Light) is functioning and is not on when the engine is running, and that the OBD (On Board Diagnostic) system is ready for testing. Normally, the OBD system will be ready. The OBD system may not be ready if your vehicle was recently serviced, if you recently had a dead battery, or a battery replacement. If the OBD system should be determined not ready for the I/M test, your vehicle may fail the test. Your vehicle has a simple ignition key actuated test, which you can use prior to going to the test station. To check if your vehicle's OBD system is ready, you must do the following: 1. Insert your ignition key into the ignition switch.