2006 CADILLAC DTS PROFESSIONAL check engine

If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended
oils with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you
know when to change the engine oil and lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil
is changed.When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL SOON message in
the Driver Information Center (DIC) will come on.
Change your oil as soon as possible within the next
600 miles (1 000 km). It is possible that, if you are
driving under the best conditions, the oil life system may
not indicate that an oil change is necessary for over a
year. However, the engine oil and lter must be changed
at least once a year and at this time the system must
be reset. Your dealer has GM-trained people who
will perform this work using genuine GM parts and reset
the system. It is also important to check the oil
regularly and keep it at the proper level.
If the system is ever reset accidentally, you must
change the oil at 3,000 miles (5 000 km) since the last
oil change. Remember to reset the oil life system
whenever the oil is changed.
5-16

Follow these steps to reinstall the cover to the engine
air cleaner/lter housing:
1. Align the two hinges located on the inboard side of
the cover.
2. Push the cover slightly down and towards the
engine to engage the tabs in the hinges and
align the two screws.
3. Tighten the two screws on the top of the engine air
cleaner/lter housing cover.
{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 Transaxle Fluid
When to Check and Change Automatic
Transaxle Fluid
A good time to check your automatic transaxle uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transaxle uid listed inRecommended
Fluids and Lubricants on page 6-12.
How to Check Automatic
Transaxle Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage the
transaxle. Too much can mean that some of the
uid could come out and fall on hot engine or
exhaust system parts, starting a re. Too little uid
could cause the transaxle to overheat. Be sure
to get an accurate reading if you check the
transaxle uid.
5-19

Wait at least 30 minutes before checking the transaxle
uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
you may have to drive longer.
Checking the Fluid Level
Prepare you vehicle as follows:
1. Park your vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in PARK (P).3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position
the shift lever in PARK (P).
4. Let the engine run at idle for three to ve minutes.
Then, without shutting off the engine, follow
these steps:
The transaxle uid cap is located next to the radiator
hose and below the engine air cleaner/lter assembly on
the driver’s side of the vehicle, and is marked TRANS
FLUID. SeeEngine Compartment Overview on
page 5-12for more information on location.
1. After removing the engine air cleaner/lter assembly
to reach the transaxle uid cap, turn the cap
counterclockwise to remove. Pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds, and
then pull it back out again.
5-20

3. Check both sides of the dipstick, and read the
lower level. The uid level must be in the
cross-hatched area.
4. If the uid level is in the acceptable range, push
the dipstick back in all the way and turn the
handle clockwise. Reinstall the engine air
cleaner/lter assembly.
How to Add Automatic Transaxle Fluid
Refer to the Maintenance Schedule to determine
what kind of transaxle uid to use. SeeRecommended
Fluids and Lubricants on page 6-12.
If the uid level is low, add only enough of the proper
uid to bring the level into the cross-hatched area on
the dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than
one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transaxle
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transaxle uid listed in
Recommended Fluids and Lubricants on page 6-12.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transaxle Fluid,” earlier in this section.
4. When the correct uid level is obtained, push
the dipstick back in all the way and turn the
handle clockwise.
5-21

{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 would not get the overheat warning.
Your 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 you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not 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 two times a year,
have your dealer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
5-23

Checking Coolant
The engine coolant surge
tank is located toward the
rear of the engine
compartment on the
passenger’s side of
the vehicle.
For more information on location, seeEngine
Compartment Overview on page 5-12.{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 mark, located on the side of the surge tank
that faces the engine.
5-24

{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.
{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 is overheating, 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. See
Overheated Engine Protection Operating Mode on
page 5-27for information on driving to a safe place
in an emergency.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant
may require changing sooner, at 30,000 miles
(50 000 km) or 24 months, whichever occurs rst.
Any repairs would not be covered by your warranty.
Always use DEX-COOL
®(silicate-free) coolant in
your vehicle.
5-29

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 level is not at the FULL COLD mark located
on the side of the surge tank, add enough of a
50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant at the coolant surge tank to
bring the level to the FULL COLD mark, but be sure
the cooling system, including the coolant surge
tank pressure cap (if equipped), is cool before you
do it. SeeEngine Coolant on page 5-22for more
information.If no coolant is visible in the surge tank, add coolant as
follows:
{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.
5-30