Onboard Diagnostic System - Obd Ii; Loose Fuel Filler Cap Message - Jeep Wrangler 2013 Owner's Manual

570 MAINTAINING YOUR VEHICLE
ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the "Malfunction Indicator Light" (MIL). It
will also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.
CAUTION!
• Prolonged driving with the MIL on could cause
further damage to the emission control system. It
could also affect fuel economy and drivability. The
vehicle must be serviced before any emissions tests
can be performed.
• If the MIL is flashing while the engine is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.

Loose Fuel Filler Cap Message

After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is possibly loose, improp-
erly installed, or damaged. A "gASCAP" message will be
displayed in the odometer. Tighten the gas cap until a
clicking sound is heard. This is an indication that the