Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance
471
Severe Conditions
Requiring More Frequent
Maintenance*
.
Public service, military,
or commercial use vehicles
to include the following:
‐
Ambulances, police cars,
and emergency rescue
vehicles.
‐
Civilian vehicles such as
light duty pick-up trucks,
SUVs, and passenger cars
that are used in military
applications.
‐
Recovery vehicles such as
tow trucks and flatbed
single vehicle carriers or
any vehicle that is
consistently used in towing
trailers or other loads.
‐
High use commercial
vehicles such as courier
delivery vehicles, private
security patrol vehicles,
or any vehicles that
operate on a 24
–
hour
basis.
‐
Any vehicle consistently
operated in a high sand or
dust environment such as
those used on oil pipelines
and similar applications.
.
Vehicles that are regularly
used for short trips of 6 km
(4 mi) or less.
The oil life indicator will show
you when to change the oil
and filter. Under severe
conditions the indicator may
come on before 12 000 km
(7,500 mi).
* Footnote: Under extreme
driving conditions listed
above, it may be necessary
to replace your spark plugs
at more frequent intervals.
For further assistance in
determining the most
suitable service maintenance
intervals for your vehicle,
please contact your
authorized GM Dealer.
Extreme service is for
vehicles mainly driven
off-road in four-wheel drive
or used in farming, mining,
forestry, or snow plowing.
Additional Required
Services
—
Severe Service
Every 72 000 km (45,000 mi)
.
Change automatic
transmission fluid and filter.
.
Change transfer case fluid,
if equipped with AWD. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
.
Change rear axle fluid, with
limited slip differential. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High