2003 CADILLAC CTS Owners Manual

6-19
Passenger Compartment Air Filter
The passenger compartment air filter traps most of the
pollen from the air entering your vehicle. Like your
vehicle's engine air cleaner/filter, it needs to be changed
periodically. For how often to change the passenger
compartment air filter, see ªScheduled Maintenance
Servicesº in the Index.
The passenger compartment air filter is located
underneath the hood below the windshield wiper arm on
the passenger's side of the vehicle. See ªEngine
Compartment Overviewº in the Index for more
information on location.
Use the procedure listed below to replace the passenger
compartment air filter:
1. Turn the ignition to ON with the engine off.2. Turn on the windshield wipers and turn them off
again when the wipers are in the out
-wipe position.
The wipers will be straight up and down on
the windshield.
This will allow you access to the leaf screen
under which is located the passenger compartment
air filter.
3. Open the hood to access the engine compartment.
See ªHood Releaseº listed earlier in this section for
more information.
4. Remove the four screws that hold the leaf screen in
place and lift off the screen by lifting and sliding
toward the center of the vehicle.
5. Pull out on the two tabs located on each end of the
filter cover.
6. Lift the filter cover off by pulling it straight upward.
7. Remove the old filter and insert a new one. Make
sure the arrow on the filter is pointing toward the
passenger compartment.
See ªNormal Maintenance Replacement Partsº
later in this section for the correct part number for
the filter.
8. Reverse Steps 1 through 6 to reinstall the cover.

6-20
Automatic Transmission Fluid
It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid
loss. If a leak occurs, take your vehicle to the dealership
service department and have it repaired as soon as
possible. You may also have your fluid level checked
by your dealer or service center when you have your
oil changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, the fluid and filter do not require changing.NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.

6-21
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the fluid in your manual
transmission doesn't require changing.
How to Check
Because this operation can be difficult, you may
choose to have this done at your Cadillac dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot exhaust
system parts, starting a fire. Too little fluid could
cause the transmission to overheat. Be sure to get
an accurate reading if you check your
transmission fluid.
Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission is
cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
How to Add Fluid
Here's how to add fluid. Refer to the Maintenance
Schedule to determine what kind of fluid to use. See
ªRecommended Fluids and Lubricantsº in the Index.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
filler plug hole.
3. Install the filler plug. Be sure the plug is fully seated.

6-22 How to Reset the Change Transmission
Fluid Message and the Transmission Fluid
Indicator (Automatic Transmission Only)
After the transmission fluid has been changed, the
Change Trans Fluid message and the transmission fluid
life indicator must be reset. To reset the message and
indicator, use one of the following procedures:
Base Audio System
Press the CLR button located to the right of the DIC
display to acknowledge the CHANGE TRANS FLUID
message. This will clear the message from the display
and reset it.
To reset the transmission fluid life indicator, use the
following steps:
1. Press the up or down arrow on the INFO button
located to the right of the DIC display to access the
DIC menu.
2. Once the XXX% TRANS FLUID LIFE menu item is
highlighted, press and hold the CLR button.
The percentage will return to 100, and the
transmission fluid life indicator will be reset.
3. Repeat the steps if the percentage does not
return to 100.Navigation System
Press the multi
-function button located to the right of
the DIC display, next to the OK prompt to acknowledge
the Change Trans Fluid message. This will clear the
message from the display and reset it.
To reset the transmission fluid life indicator, use the
following steps:
1. Turn the system on by pressing the PWR/VOL knob
once. The PWR/VOL knob is located to the lower
left of the DIC display.
2. Press the INFO button located to the left of
the DIC display to access the Vehicle Info
(Information) menu.
3. Turn the TUNE/SEL knob located to the lower right
of the DIC display until Trans Fluid Life is
highlighted. Press the knob once to select it.
4. Once XXX% Trans Fluid Life is displayed, press the
multi
-function button next to the Reset prompt in the
upper right corner of the display.
The percentage will return to 100, and the
transmission fluid life indicator will be reset.
5. Repeat the steps if the percentage does not
return to 100.

6-23
Hydraulic Clutch
It is not necessary to regularly check clutch fluid unless
you suspect there is a leak in the system. Adding fluid
won't correct a leak.
A fluid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
The hydraulic clutch reservoir is located in the engine
compartment on the driver's side, near the brake master
cylinder reservoir. See ªEngine Compartment Overviewº
in the Index for more information on location.Refer to the Maintenance Schedule to determine how
often you should check the fluid level in your clutch
master cylinder reservoir and for the proper fluid. See
ªOwner Checks and Servicesº and ªRecommended
Fluids and Lubricantsº in the Index.
How to Check and Add Fluid
Make sure the fluid
level is at the MIN line
shown. If it isn't,
remove the cap and
add the proper fluid
until the level reaches
the MIN line on the
side of the reservoir.

6-24
Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªPeriodic Maintenance
Inspectionsº and ªScheduled Maintenance Servicesº in
the Index.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.

6-25
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº
in the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to the
system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-26 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.