Heavy Duty Use Of The Vehicle
Change engine oil at 4,000 miles (6,500 km) or 350 hours of
engine run time if the vehicle is operated in a dusty and off
road environment or is operated predominately at idle or
only very low engine RPM’s. This type of vehicle use is
considered Severe Duty.
6.4L Engine
The scheduled maintenance services listed in this manual
must be done at the times or mileages specified to protect
your vehicle warranty and ensure the best vehicle perfor-
mance and reliability. More frequent maintenance may be
needed for vehicles in severe operating conditions, such as
dusty areas and very short trip driving. Inspection and
service should also be done anytime a malfunction is
suspected.
The oil change indicator system will remind you that it is
time to take your vehicle in for scheduled maintenance.
A “Oil Change Required” message will be displayed in the
instrument cluster and a single chime will sound, indicat-
ing that an oil change is necessary.Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Have your vehicle serviced as
soon as possible, within the next 500 miles (800 km).
NOTE:
•
The oil change indicator message will not monitor the
time since the last oil change. Change your vehicle’s oil
if it has been six months since your last oil change, even
if the oil change indicator message is NOT illuminated.
• Change your engine oil more often if you drive your
vehicle off-road/track usage for an extended period of
time.
• Under no circumstances should oil change intervals
exceed 6,000 miles (10,000 km) or six months, whichever
comes first.
An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
an authorized dealer, the message can be reset by referring
to the steps described under “Instrument Cluster Display”
in “Getting To Know Your Instrument Panel” for further
information.
8
SERVICING AND MAINTENANCE 365
