2006 CADILLAC CTS check engine

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Oil Life System..................................5-20
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Manual Transmission Fluid.............................5-24
Hydraulic Clutch...........................................5-25
Engine Coolant.............................................5-26
Coolant Surge Tank Pressure Cap..................5-28
Engine Overheating.......................................5-28Overheated Engine Protection
Operating Mode........................................5-30
Cooling System............................................5-31
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-48
Headlamp Aiming...........................................5-49
Bulb Replacement..........................................5-52
High Intensity Discharge (HID) Lighting............5-52
Halogen Bulbs..............................................5-52
Front Turn Signal and Fog Lamps...................5-53
Taillamps, Turn Signal, Stoplamps and
Sidemarker Lamps.....................................5-53
Back-Up and License Plate Lamps..................5-54
Replacement Bulbs.......................................5-55
Windshield Wiper Blade Replacement..............5-55
Tires..............................................................5-57
Tire Sidewall Labeling...................................5-58
Tire Terminology and Denitions.....................5-61
Run-Flat Tires (CTS-V)..................................5-64
Ination - Tire Pressure.................................5-65
Tire Pressure Monitor System.........................5-68
Section 5 Service and Appearance Care
5-1

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your vehicle
can affect the airow around it. This may cause
wind noise and affect windshield washer performance.
Check with your dealer before adding equipment to
the outside of your vehicle.
Fuel
The 8th digit of your Vehicle Identication Number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-103.
Gasoline Octane
If your vehicle has the 2.8L V6 engine (VIN Code T),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you may 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,
your 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 may choose to use middle grade 89 octane
unleaded gasoline. If the octane rating is less than
87, you may 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, your
engine needs service.
5-5

If your vehicle has the 6.0L V8 engine (VIN Code U),
use premium unleaded gasoline with a posted
octane rating of 91 or higher. You may also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration may be slightly reduced,
and you may notice a slight audible knocking noise,
commonly referred to as spark knock. If the octane is
less than 87, you may notice a heavy knocking
noise when you drive. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
Otherwise, you might damage your engine. If you are
using gasoline rated at 87 octane or higher and you
hear heavy knocking, your engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
General Motors recommends against the use of
gasolines containing MMT. SeeAdditives on
page 5-6for 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 may be affected. The malfunction
indicator lamp may turn on and your vehicle may fail
a smog-check test. SeeMalfunction Indicator Lamp
on page 3-41. If this occurs, return to your authorized
GM dealer for diagnosis. If it is determined that the
condition is caused by the type of fuel used, repairs
may not be covered by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. In most cases, you should not have to add
anything to your fuel. However, some gasolines contain
only the minimum amount of additive required to
meet U.S. Environmental Protection Agency regulations.
5-6

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
Dispense gasoline only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer
and other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-105.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-37.
C. Battery. SeeBattery on page 5-41.
D. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-29.
E. Power Steering Fluid Reservoir (Under Engine
Cover). SeePower Steering Fluid on page 5-36.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-16.G. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-16.
H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
I. Hydraulic Clutch Reservoir (If Equipped)
(Not Shown). See “When to Check and What to
Use” underHydraulic Clutch on page 5-25.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 5-28andCooling System on page 5-31.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
5-13

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-105.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-37.
C. Battery. SeeBattery on page 5-41.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-16.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-29.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-16.G. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-36.
H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
I. Hydraulic Clutch Reservoir. See “When to Check
and What to Use” underHydraulic Clutch on
page 5-25.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 5-28andCooling System on page 5-31.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
5-15

Engine Oil
There is an oil pressure
light in the instrument
cluster and an Oil
Pressure Low - Stop
Engine message on
the Driver Information
Center (DIC).
If the light and/or message appear, it means you need
to check the engine oil level right away. For more
information, see “Oil Pressure Low - Stop Engine”
underDIC Warnings and Messages on page 3-61and
Oil Pressure Light on page 3-44. You should check
the engine oil level regularly; this is an added reminder.
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-16

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 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, your 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 service people who will perform this work
using genuine GM parts and reset the system. It is also
important to check your oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System and the Oil Life Indicator
The Engine Oil Life System calculates when to change
your engine oil and lter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change your oil prior to a change engine oil
message in the DIC being turned on, reset the system.
After the oil has been changed, the change engine
oil message and the oil life indicator must be reset.
To reset the message and indicator, use one of
the following procedures:
Base Audio System
Press the CLR button located to the right of the DIC
display to acknowledge the change engine oil message.
This will clear the message from the display and reset it.
To reset the oil life indicator, use the following steps:
1. Press the up or down arrow on the INFO button
located to the right of the DIC display to access
the DIC menu.
2. Once XXX% ENGINE OIL LIFE menu item is
highlighted, press and hold the CLR button.
The percentage will return to 100, and the oil life
indicator will be reset. Repeat the steps if the
percentage does not return to 100.
3. Turn the key to OFF.
5-20