Dodge 2009 Ram Chassis Cab - Manual (Page 338)

ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Vehicles with 5.7L engines are equipped with a sophisti-
cated onboard diagnostic system called OBD II. This
system monitors the performance of the emissions, en-
gine, and automatic transmission control systems. When
these systems are operating properly, your vehicle will
provide excellent performance and fuel economy, as well
as engine emissions 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 driveable 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 driveability. The
vehicle must be serviced before any emissions tests
can be performed.
If the MIL is flashing, severe catalytic converter
damage and power loss will soon occur. Immediate
service is required.
Loose Fuel Filler Cap Message
If the vehicle’s diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
gASCAP message will be displayed 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 odometer reset button to turn the
message off. If the problem persists, the message will
336 MAINTAINING YOUR VEHICLE