2008 CADILLAC CTS check engine

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there
and the engine backres, you could be burned.
Do not drive with it off, and be careful working
on the engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre
can cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when
you are driving.
Automatic Transmission Fluid
How to Check Automatic Transmission
Fluid
It is not necessary to check the transmission uid level.
A transmission uid leak is the only reason for uid loss.
If a leak occurs, take the vehicle to the dealer/retailer
service department and have it repaired as soon as
possible.
There is a special procedure for checking and changing
the transmission uid. Because this procedure is difficult,
you should have this done at the dealer/retailer service
department. Contact your dealer/retailer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-17.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-14.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be
sure to use the uid listed inRecommended Fluids
and Lubricants on page 6-14.
5-25

Manual Transmission Fluid
When to Check Manual Transmission
Fluid
It is not necessary to check the manual transmission
uid level. A transmission uid leak is the only reason
for uid loss. If a leak occurs, take the vehicle to
your dealer/retailer service department and have it
repaired as soon as possible.
How to Check Manual Transmission
Fluid
Because this operation can be difficult, you may choose
to have this done at your dealer/retailer 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 uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission uid.
Check the uid 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 ngers on the
transmission case.
To check the uid level, do the following:
1. Remove the ller plug.
2. Check that the lubricant level is up to the bottom of
the ller plug hole.
3. If the uid level is good, replace the gasket and
reinstall the ller plug.
With either vehicle, be sure the plug is fully seated.
If the uid level is low, add more uid as described
in the next steps.
5-26

How to Add Manual Transmission Fluid
Here is how to add uid. SeeRecommended Fluids
and Lubricants on page 6-14to determine which type of
uid to use.
1. Remove the ller plug.
2. Add uid at the ller plug hole. Add only enough
uid to bring the uid level up to the bottom of the
ller plug hole.
3. Replace the gasket and reinstall the ller plug.
Be sure the plug is fully seated.
Hydraulic Clutch
It is not necessary to regularly check clutch uid unless
you suspect there is a leak in the system. Adding
uid will not correct a leak. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
When to Check and What to Use
The hydraulic clutch uid
reservoir cap has this
symbol on it. SeeEngine
Compartment Overview
on page 5-14for reservoir
location.
Refer to the Maintenance Schedule for the proper uid
to use. SeeRecommended Fluids and Lubricants on
page 6-14. The uid requires changing every two years.
SeeAdditional Required Services on page 6-6.
5-27

How to Check and Add Fluid
Visually check the clutch uid reservoir to make sure the
uid level is at the MIN (Minimum) line on the side of the
reservoir. The hydraulic clutch uid system should be
kept closed and sealed. Do not remove the cap to check
the uid level or to top-off the uid level. Remove the cap
only when necessary to add the proper uid until the level
reaches the MIN line.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains the cooling system and how to
add coolant when it is low. If the engine overheats, see
Engine Overheating on page 5-31.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Allow the warning lights and gages to work as they
should.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs would
not be covered by the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
5-28

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but would
not get the overheat warning. The engine could
catch re and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant.Notice:If an improper coolant mixture is used,
the engine could overheat and be badly damaged.
The repair cost would not be covered by the vehicle
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 once or twice a
year, have your dealer/retailer check your cooling
system.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 6-14for more information.
5-29

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. SeeEngine Compartment
Overview on page 5-14for 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
FROID/FULL COLD line on the side of the surge tank.
Follow the arrow from the top of the tank down the
side to the horizontal mark.
5-30

{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine hot light is on, both fans should be running.
If they are not, your vehicle needs service.Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
SeeOverheated Engine Protection Operating Mode
on page 5-33for information on driving to a safe
place in an emergency.
Notice:Using coolant other than DEX-COOL®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in
the vehicle.
5-35

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible but
the coolant level is not at the FROID/FULL COLD line on
the side of the coolant surge tank, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is cool
before you do it. SeeEngine Coolant on page 5-28for
more information.
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the coolant
surge tank pressure cap — even a little — they
can come out at high speed. Never turn the
cap when the cooling system, including the
coolant surge tank pressure cap, is hot. Wait
for the cooling system and coolant surge tank
pressure cap to cool if you ever have to turn
the pressure cap.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The engine
could catch re and you or others could be
burned. Use a 50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
5-36