2008 CADILLAC CTS octane

An emission system malfunction might be corrected by
doing the following:
Make sure the fuel cap is fully installed. SeeFilling
the Tank on page 5-9. The diagnostic system can
determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap
allows fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
If the vehicle has been driven through a deep
puddle of water, the vehicle’s electrical system
might be wet. The condition is usually corrected
when the electrical system dries out. A few driving
trips should turn the light off.
Make sure to fuel the vehicle with quality fuel.
Poor fuel quality causes the engine not to run
as efficiently as designed and may cause: stalling
after start-up, stalling when the vehicle is changed
into gear, misring, hesitation on acceleration,
or stumbling on acceleration. These conditions
might go away once the engine is warmed up.
If one or more of these conditions occurs, change
the fuel brand used. It will require at least one
full tank of the proper fuel to turn the light off.
SeeGasoline Octane on page 5-7.
If none of the above have made the light turn off,
your dealer/retailer can check the vehicle.The dealer/retailer has the proper test equipment
and diagnostic tools to x any mechanical or
electrical problems that might have developed.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might begin programs to inspect the emission control
equipment on the vehicle. Failure to pass this inspection
could prevent getting a vehicle registration.
Here are some things to know to help the vehicle pass
an inspection:
The vehicle will not pass this inspection if the check
engine light is on or not working properly.
The vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen
if the battery has recently been replaced or if the
battery has run down. The diagnostic system is
designed to evaluate critical emission control
systems during normal driving. This can take several
days of routine driving. If this has been done and the
vehicle still does not pass the inspection for lack of
OBD system readiness, your dealer/retailer can
prepare the vehicle for inspection.
3-43

Service............................................................5-4
Accessories and Modications..........................5-4
California Proposition 65 Warning.....................5-5
California Perchlorate Materials Requirements.....5-5
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside of the
Vehicle......................................................5-6
Fuel................................................................5-6
Gasoline Octane............................................5-7
Gasoline Specications....................................5-7
California Fuel...............................................5-7
Additives.......................................................5-8
Fuels in Foreign Countries...............................5-8
Filling the Tank..............................................5-9
Filling a Portable Fuel Container.....................5-11
Checking Things Under the Hood....................5-12
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-16
Engine Oil Life System..................................5-19
Engine Cover...............................................5-21
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-25
Manual Transmission Fluid.............................5-26Hydraulic Clutch...........................................5-27
Engine Coolant.............................................5-28
Coolant Surge Tank Pressure Cap..................5-31
Engine Overheating.......................................5-31
Overheated Engine Protection
Operating Mode........................................5-33
Cooling System............................................5-34
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-50
Rear Axle.......................................................5-51
Headlamp Aiming...........................................5-52
Bulb Replacement..........................................5-55
High Intensity Discharge (HID) Lighting............5-55
Halogen Bulbs..............................................5-55
Front Turn Signal and Fog Lamps...................5-56
License Plate Lamp......................................5-56
Replacement Bulbs.......................................5-57
Windshield Wiper Blade Replacement..............5-57
Section 5 Service and Appearance Care
5-1

Gasoline Octane
If your vehicle has the 3.6L V6 engine (VIN Code V),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
If your vehicle has the 3.6L V6 engine (VIN Code 7),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. For best performance or trailer
towing, you could choose to use middle grade 89 octane
unleaded gasoline. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-8
for additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-41. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
5-7

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
and intake valves clean, or if your vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline. Also,
your dealer/retailer has additives that will help correct and
prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available in
your area. We recommend that you use these gasolines,
if they comply with the specications described earlier.
However, E85 (85% ethanol) and other fuels containing
more than 10% ethanol must not be used in vehicles that
were not designed for those fuels.
Notice:Your vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under your
warranty.Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer/retailer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-8

Using the Maintenance Schedule
We want to help you keep your vehicle in good working
condition. But we do not know exactly how you will drive
it. You might drive very short distances only a few times a
week. Or you might drive long distances all the time in
very hot, dusty weather. You might use your vehicle in
making deliveries. Or you might drive it to work, to do
errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need
more frequent checks and replacements. So please
read the following and note how you drive. If you have
any questions on how to keep your vehicle in good
condition, see your dealer/retailer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits. You will nd these limits on the Tire and
Loading Information label. SeeLoading the Vehicle
on page 4-22.
are driven on reasonable road surfaces within legal
driving limits.
use the recommended fuel. SeeGasoline Octane
on page 5-7.The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-8for further information.
{CAUTION:
Performing maintenance work on a vehicle
can be dangerous. In trying to do some jobs,
you can be seriously injured. Do your own
maintenance work only if you have the
required know-how and the proper tools and
equipment for the job. If you have any doubt,
see your dealer/retailer to have a qualied
technician do the work. SeeDoing Your
Own Service Work on page 5-5.
Some maintenance services can be complex.
So, unless you are technically qualied and have
the necessary equipment, you should have your
dealer/retailer do these jobs.
6-3

Engine
Air Cleaner/Filter.........................................5-21
Check and Service Engine Soon Light............3-41
Coolant......................................................5-28
Coolant Heater............................................2-37
Coolant Temperature Gage...........................3-40
Coolant Temperature Warning Light................3-40
Cover........................................................5-21
Drive Belt Routing.......................................6-17
Engine Compartment Overview......................5-14
Exhaust.....................................................2-48
Oil .............................................................5-16
Oil Life System...........................................5-19
Oil Pressure Gage.......................................3-45
Overheated Protection Operating Mode...........5-33
Overheating................................................5-31
Speed Limiter.............................................3-32
Starting......................................................2-35
Entry Lighting.................................................3-20
Event Data Recorders.....................................7-19
Extender, Safety Belt.......................................1-32
Exterior Lighting Battery Saver..........................3-20
F
Filter
Engine Air Cleaner......................................5-21
Finish Damage.............................................5-119
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-82
Flat Tire, Changing........................................5-102
Flat Tire, Storing...........................................5-110
Fluid.............................................................5-26
Automatic Transmission................................5-25
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp
Fog ...........................................................3-19
Fog Lamp Light..............................................3-46
Folding Rear Seat...........................................1-11
Fuel............................................................... 5-6
Additives...................................................... 5-8
California Fuel.............................................. 5-7
Filling a Portable Fuel Container....................5-11
Filling the Tank............................................. 5-9
Fuels in Foreign Countries.............................. 5-8
Gage .........................................................3-47
Gasoline Octane........................................... 5-7
Gasoline Specications.................................. 5-7
Running Out of...........................................2-49
Fuses
Fuses and Circuit Breakers.........................5-123
Rear Compartment Fuse Block....................5-126
Underhood Fuse Block...............................5-123
Windshield Wiper.......................................5-122
5

G
Gage
Engine Coolant Temperature.........................3-40
Engine Oil Pressure.....................................3-45
Fuel..........................................................3-47
Speedometer..............................................3-32
Tachometer.................................................3-32
Garage Door Opener.......................................2-58
Gasoline
Octane........................................................ 5-7
Specications............................................... 5-7
Glove Box.....................................................2-62
GM Mobility Reimbursement Program.................. 7-7
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-2
Headlamp
Aiming .......................................................5-52
Headlamps....................................................3-17
Adaptive Forward Lighting System.................3-19
Bulb Replacement.......................................5-55Headlamps (cont.)
Daytime Running Lamps...............................3-18
Flash-to-Pass............................................... 3-9
Front Turn Signal and Fog Lamps..................5-56
Halogen Bulbs............................................5-55
High Intensity Discharge (HID) Lighting...........5-55
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-17
Washer......................................................3-13
Wiper Activated...........................................3-17
Heated Seats................................................... 1-6
Heater...........................................................3-24
Engine Coolant...........................................2-37
Highbeam On Light.........................................3-47
High-Speed Operation, Tires.............................5-68
Highway Hypnosis...........................................4-16
Hill and Mountain Roads..................................4-16
Hood
Checking Things Under................................5-12
Release.....................................................5-12
Horn ............................................................... 3-6
How to Wear Safety Belts Properly...................1-17
Hydraulic Clutch.............................................5-27
6