2010 CADILLAC DTS Owners Manual

Checking Coolant
The vehicle must be on a level surface when checkingthe coolant level.
Check to see if coolant is visible in the coolant recoverytank. If the coolant inside the coolant recovery tank isboiling, do not do anything else until it cools down.If coolant is visible but the coolant level is not ator above the FULL COLD mark, add a 50/50 mixture ofclean, drinkable water and DEX-COOL®coolant atthe coolant recovery tank, but be sure the coolingsystem is cool before this is done. SeeEngine Coolanton page 6-23for more information.
How to Add Coolant to the Surge Tank
{WARNING:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol and
it will burn if the engine parts are hot enough. Do
not spill coolant on a hot engine.
Notice:This vehicle has a specific coolant fillprocedure. Failure to follow this procedure couldcause the engine to overheat and be severelydamaged.
{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
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{WARNING:
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 surge tank
pressure cap — even a little — they can come out
at high speed. Never turn the cap when the
cooling system, including the surge tank pressure
cap, is hot. Wait for the cooling system and surge
tank pressure cap to cool if you ever have to turn
the pressure cap.
If no coolant is visible in the surge tank, add coolantas follows:
1. Remove the coolantsurge tank pressurecap when the coolingsystem, includingthe coolant surge tankpressure cap andupper radiator hose, isno longer hot.
Turn the pressure cap slowly counterclockwise.If you hear a hiss, wait for that to stop. A hissmeans there is still some pressure left.
2. Keep turning the cap and remove it.
3. Fill the coolant surgetank with the propermixture to theFULL COLD markon the side ofthe coolant surge tank.
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4. With the coolant surge tank cap off, start the engineand let it run until you can feel the upper radiatorhose getting hot. Watch out for the enginecooling fans.
By this time, the coolant level inside the coolantsurge tank may be lower. If the level is lower, addmore of the proper mixture to the coolant surge tankuntil the level reaches the FULL COLD mark onthe side of the coolant surge tank.
5. Replace the cap. Be sure the cap is hand-tight andfully seated.
Notice:If the pressure cap is not tightly installed,coolant loss and possible engine damage mayoccur. Be sure the cap is properly and tightlysecured.
If coolant is needed, add the proper DEX-COOL®
coolant mixture at the coolant recovery tank.
Engine Overheating
The vehicle has several indicators to warn of engineoverheating.
There is an engine temperature warning light and/orgage on the instrument panel cluster. SeeEngineCoolant Temperature Warning Light on page 4-55andEngine Coolant Temperature Gage on page 4-56.
The vehicle may also display a ENGINE OVERHEATEDIDLE ENGINE message or an ENGINE OVERHEATEDSTOP ENGINE message displayed in the DriverInformation Center (DIC). SeeDIC Warnings andMessages on page 4-67for more information. You willalso hear a chime.
4.6L L37 Engine shown, 4.6L LD8 Engine similar
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You may decide not to lift the hood when this warningappears, but instead get service help right away.SeeRoadside Service on page 8-7.
If you do decide to lift the hood, make sure the vehicleis parked on a level surface.
Then check to see if the engine cooling fans arerunning. If the engine is overheating, both fans shouldbe running. If they are not, do not continue to runthe engine and have the vehicle serviced.
Notice:Engine damage from running the enginewithout coolant is not covered by the warranty.
Notice:If the engine catches fire while driving withno coolant, the vehicle can be badly damaged.The costly repairs would not be covered bythe vehicle warranty. SeeOverheated EngineProtection Operating Mode on page 6-29forinformation on driving to a safe place in anemergency.
If Steam Is Coming From The Engine
Compartment
{WARNING:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from the
vehicle until it cools down. Wait until there is no sign
of steam or coolant before you open the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating Mode
on page 6-29for information on driving to a safe
place in an emergency.
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If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no steamcan be seen or heard, the problem may not be tooserious. Sometimes the engine can get a little too hotwhen the vehicle:
•Climbs a long hill on a hot day.
•Stops after high-speed driving.
•Idles for long periods in traffic.
•Tows a trailer.
If the overheat warning is displayed with no sign ofsteam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature andto the highest fan speed. Open the windows asnecessary.
3. In heavy traffic, let the engine idle in N (Neutral) whilestopped. If it safe to do so, pull off the road, shift toP (Park) or N (Neutral) and let the engine idle.
If the temperature overheat gage is no longer in theoverheat zone or an overheat warning no longer displays,the vehicle can be driven. Continue to drive the vehicleslow for about 10 minutes. Keep a safe vehicle distancefrom the car in front of you. If the warning does not comeback on, continue to drive normally.
If the warning continues, pull over, stop, and park thevehicle right away.
If there is no sign of steam, idle the engine for threeminutes while parked. If the warning is still displayed, turnoff the engine until it cools down. Also, see!OverheatedEngine Protection Operating Mode!next in this section.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and themessage ENGINE OVERHEATED STOP ENGINE isdisplayed, an overheat protection mode which alternatesfiring groups of cylinders helps prevent engine damage.In this mode, you will notice a loss in power andengine performance. This operating mode allows yourvehicle to be driven to a safe place in an emergency.Driving extended miles (km) and/or towing a trailer in theoverheat protection mode should be avoided.
Notice:After driving in the overheated engineprotection operating mode, to avoid engine damage,allow the engine to cool before attempting anyrepair. The engine oil will be severely degraded.Repair the cause of coolant loss, change the oil andreset the oil life system. SeeEngine Oil onpage 6-13.
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Power Steering Fluid
The power steering fluidreservoir is located next tothe underhood fuseblock on the passengerside of the vehicle.SeeEngine CompartmentOverview on page 6-12for more informationon location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering fluidunless you suspect there is a leak in the system oryou hear an unusual noise. A fluid loss in this systemcould indicate a problem. Have the system inspectedand repaired.
How to Check Power Steering Fluid
To check the power steering fluid:
1. Turn the key off and let the engine compartmentcool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a cleanrag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level onthe dipstick.
The level should be at the FULL COLD mark. Ifnecessary, add only enough fluid to bring the level up tothe mark.
What to Use
To determine what kind of fluid to use, seeRecommended Fluids and Lubricants on page 7-8.Always use the proper fluid.
Notice:Use of the incorrect fluid may damage thevehicle and the damages may not be covered bythe vehicle’s warranty. Always use the correct fluidlisted inRecommended Fluids and Lubricantson page 7-8.
6-30

Windshield Washer Fluid
What to Use
When the vehicle needs windshield washer fluid, besure to read the manufacturer’s instructions before use.If the vehicle will be operating in an area where thetemperature may fall below freezing, use a fluid that hassufficient protection against freezing.
Adding Washer Fluid
The WASHER FLUID LOW ADD FLUID message willbe displayed on the Driver Information Center (DIC)when the fluid is low. SeeDIC Warnings and Messageson page 4-67for more information.
Open the cap with thewasher symbol on it. Addwasher fluid until thetank is full. SeeEngineCompartment Overview onpage 6-12for reservoirlocation.
Notice:
•When using concentrated washer fluid, follow
the manufacturer’s instructions for addingwater.
•Do not mix water with ready-to-use washer fluid.
Water can cause the solution to freeze anddamage your washer fluid tank and other partsof the washer system. Also, water does notclean as well as washer fluid.
•Fill the washer fluid tank only three-quarters full
when it is very cold. This allows for fluidexpansion if freezing occurs, which coulddamage the tank if it is completely full.
•Do not use engine coolant (antifreeze) in your
windshield washer. It can damage the vehicle’swindshield washer system and paint.
6-31

Brakes
Brake Fluid
The brake master cylinderreservoir is filled with DOT3 brake fluid. SeeEngine CompartmentOverview on page 6-12forreservoir location andaccess.
There are only two reasons why the brake fluid level inthe reservoir might go down:
•The brake fluid level goes down because of normal
brake lining wear. When new linings are installed,the fluid level goes back up.
•A fluid leak in the brake hydraulic system can also
cause a low fluid level. Have the brake hydraulicsystem fixed, since a leak means that sooneror later the brakes will not work well.
Do not top off the brake fluid. Adding fluid does notcorrect a leak. If fluid is added when the liningsare worn, there will be too much fluid when new brakelinings are installed. Add or remove brake fluid, asnecessary, only when work is done on the brakehydraulic system.
{WARNING:
If too much brake fluid is added, it can spill on the
engine and burn, if the engine is hot enough. You
or others could be burned, and the vehicle could
be damaged. Add brake fluid only when work is
done on the brake hydraulic system.
If the ignition is on and the brake fluid is low, theSERVICE BRAKE SYSTEM message displays in theDriver Information Center (DIC). SeeDIC Warnings andMessages on page 4-67.
What to Add
Use only new DOT 3 brake fluid from a sealed container.SeeRecommended Fluids and Lubricants on page 7-8.
Always clean the brake fluid reservoir cap and thearea around the cap before removing it. This helps keepdirt from entering the reservoir.
6-32