2003 CADILLAC CTS check engine

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.

6-23
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.

6-26 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.

6-27 Checking Coolant
The coolant surge tank and pressure cap are located
on the driver's side of the vehicle, toward the rear of
the engine compartment. See ªEngine Compartment
Overviewº in the Index for more information
on location.
CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
Never turn the surge tank pressure cap
-- even a
little
-- when the engine and radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD/FROID line on the side of the surge tank. Follow
the arrow from the top of the tank down the side to the
horizontal mark.
If the Check Coolant Level message in the DIC comes
on and stays on, it means you're low on engine coolant.
See ªCheck Message, Coolant Levelº in the Index for
more information.

6-29
Power Steering Fluid
The power steering fluid reservoir is located in the
center of the engine compartment, toward the rear.
See ªEngine Compartment Overviewº in the Index
for more information on location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering
fluid unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at the fluid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to use, see
ªRecommended Fluids and Lubricantsº in the Index.
Always use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.

6-30
Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure to read
the manufacturer's instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use a fluid that has sufficient
protection against freezing. See ªEngine Compartment
Overviewº in the Index for reservoir location.
Adding Washer Fluid
The Check Washer Fluid message will appear on the
DIC when the fluid level is low. See ªCheck Message,
Washer Fluidº in the Index.
Open the cap with the
washer symbol on it.
Add washer fluid until
the tank is full.
NOTICE:

When using concentrated washer fluid,
follow the manufacturer's instructions for
adding water.

Don't mix water with ready
-to-use washer
fluid. Water can cause the solution to freeze
and damage your washer fluid tank and
other parts of the washer system. Also,
water doesn't clean as well as washer fluid.

Fill your washer fluid tank only
three
-quarters full when it's very cold.
This allows for expansion if freezing occurs,
which could damage the tank if it is
completely full.

Don't use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.

6-31
Brakes
Brake Fluid
Your brake master cylinder reservoir is on the driver's side
of the engine compartment. It is filled with DOT
-3 brake
fluid. See ªEngine Compartment Overviewº in the Index.
There are only two reasons why the brake fluid level in the
reservoir might go down. The first is that the brake fluid
goes down to an acceptable level during normal brake
lining wear. When new linings are put in, the fluid level
goes back up. The other reason is that fluid is leaking out
of the brake system. If it is, you should have your brakesystem fixed, since a leak means that sooner or later your
brakes won't work well, or won't work at all.
So, it isn't a good idea to ªtop offº your brake fluid.
Adding brake fluid won't correct a leak. If you add fluid
when your linings are worn, then you'll have too much
fluid when you get new brake linings. You should add
(or remove) brake fluid, as necessary, only when work is
done on the brake hydraulic system.
CAUTION:
If you have too much brake fluid, it can spill on the
engine. The fluid will burn if the engine is hot
enough. You or others could be burned, and your
vehicle could be damaged. Add brake fluid only
when work is done on the brake hydraulic system.
If the ignition is in ON and the brake fluid is low, the
Check Brake Fluid message will be displayed in the
DIC. See ªCheck Message, Brake Fluidº in the Index
for more information.
When your brake fluid falls to a low level, your brake
warning light will come on. See ªBrake System Warning
Lightº in the Index.

6-39
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected at least
twice a year for wear or cracking. See ªWiper Blade
Checkº in the Index.
It's a good idea to clean or replace the wiper blade
assembly on a regular basis or when worn. For proper
windshield wiper blade length and type, see ªNormal
Maintenance Replacement Partsº in the Index.
To replace the wiper blade assembly, do the following:
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 driver's side blade will be straight up and down
on the windshield.
3. Pull the windshield wiper assembly away from
the windshield.4. Lift the wiper blade assembly up so it is in a
T
-shaped position. You should be able to see a tab.