2005 Acura MDX Owner's Manual

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The temperature grades are A (the
highest), B, and C, representing the
tire’s resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled
conditions on a specif ied indoor
laboratory test wheel. Sustained high
temperature can cause the material
of the tire to degenerate and reduce
tire life, and excessive temperature
can lead to sudden tire f ailure. The
grade C corresponds to a level of
perf ormance, which all passenger
vehicle tires must meet under the
Federal Motor Vehicle Saf ety
Standard No. 109. Grades B and A
represent higher levels of
perf ormance on the laboratory test
wheel than the minimum required by
law. Warning: The temperature grade f or
this tire is established f or a tire that
is properly inf lated and not over-
loaded. Excessive speed, underinf la-
tion, or excessive loading, either
separately or in combination, can
cause heat buildup and possible tire
f ailure.
DOT T ire Quality Grading (U.S. Vehicles)
Temperature A,B,C
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287

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The tires that came on your vehicle
have a number of markings. Those
you should be aware of are described
below. Rim diameter in inches.
Load index (a numerical code
associated with the maximum
load the tire can carry).
Speed symbol (an
alphabetical code indicating
the maximum speed rating).
Tire Identif ication Number (TIN) is
a group of numbers and letters that
look like the f ollowing example TIN.
This indicates that the tire
meets all requirements of
the U.S. Department of
Transportation.Manuf acturer’s
identification mark.
Tire type code. Date of manuf acture.
Whenever tires are replaced, they
should be replaced with tires of the
same size. The f ollowing is an
exampleof tiresizewithan
explanation of what each component
means. Vehicletype(Pindicates
passenger vehicle).
Tire width in millimeters.
Aspect ratio (the tire’s section
height as a percentage of its
width).
Tire construction code (R
indicates radial).
P
225
55
R 94
V 16
DOT
B97R
FW6X2202
Tire Labeling
Tire Size
T ire Ident if icat ion Number
288
DOT B97R FW6X 2202
P225/55R16 94V

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ÎThe burning of gasoline in your
vehicle’s engine produces several by-
products. Some of these are carbon
monoxide (CO), oxides of nitrogen
(NOx) and hydrocarbons (HC).
Gasoline evaporating f rom the tank
also produces hydrocarbons. Con-
trolling the production of NOx, CO,
and HC is important to the environ-
ment. Under certain conditions of
sunlight and climate, NOx and HC
react to f orm photochemical ‘‘smog.’’
Carbon monoxide does not contri-
bute to smog creation, but it is a
poisonous gas. The United States Clean Air Act
sets standards f or automobile
emissions. It also requires that
automobile manufacturers explain to
owners how their emissions controls
workandwhattodotomaintain
them. This section summarizes how
the emissions controls work.
Scheduled maintenance is on page
.
In Canada, Acura vehicles comply
with the Canadian emission
requirements, as specif ied in an
agreement with Environment
Canada, at the time they are
manuf actured.
Your vehicle has a positive
crankcase ventilation system. This
keeps gasses that build up in the
engine’s crankcase f rom going into
the atmosphere. The positive crankcase ventilation valve routes
them from the crankcase back to the
intake manif old. They are then
drawn into the engine and burned.
As gasoline evaporates in the f uel
tank, an evaporative emissions
control canister f illed with charcoal
adsorbs the vapor. It is stored in this
canister while the engine is of f . Af ter
the engine is started and warmed up,
the vapor is drawn into the engine
and burned during driving.
The onboard ref ueling vapor
recovery (ORVR) system captures
the f uel vapors during ref ueling. The
vapors are adsorbed in a canister
f illed with activated carbon. While
driving, the f uel vapors are drawn
into the engine and burned of f .
231
Emissions Cont rols
The Clean Air Act
Crankcase Emissions Control
System Evaporative Emissions Control
System
Onboard Ref ueling Vapor
Recovery
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289

The exhaust emissions controls
include f our systems: PGM-FI,
ignition timing control, exhaust gas
recirculation and three way catalytic
converter. These f our systems work
together to control the engine’s
combustion and minimize the
amount of HC, CO, and NOx that
comes out the tailpipe. The exhaust
emissions control systems are
separate f rom the crankcase and
evaporative emissions control
systems.
The PGM-FI system uses sequential
multiport f uel injection.
It has three subsystems: air intake,
engine control, and f uel control. The
powertrain control module (PCM)
uses various sensors to determine
how much air is going into the
engine. It then controls how much
f uel to inject under all operating
conditions.This system constantly adjusts the
ignition timing, reducing the amount
of HC, CO, and NOx produced.
The exhaust gas recirculation (EGR)
system takes some of the exhaust
gas and routes it back into the intake
manif old. Adding exhaust gas to the
air/f uel mixture reduces the amount
of NOx produced when the f uel is
burned.
The three way catalytic converter is
in the exhaust system. Through
chemical reactions, it converts HC,
CO, and NOx in the engine’s exhaust
to carbon dioxide (CO ), nitrogen
(N ), and water vapor.
The emissions control systems are
covered by warranties separate from
the rest of your vehicle. Read your
warranty manual f or more informa-
tion. The emissions control systems are
designed and certif ied to work
together in reducing emissions to
levels that comply with the Clean Air
Act. To make sure the emissions
remain low, you should use only new
Acura replacement parts or their
equivalent f or repairs. Using lower
qualitypartsmayincreasethe
emissions f rom your vehicle.
2
2
Emissions Cont rols
Exhaust Emissions Controls Replacement Parts
PGM-FI Syst emIgnit ion T iming Cont rol Syst em
Exhaust Gas Recirculat ion (EGR)Syst em
Three Way Catalytic Converter
290

The three way catalytic converter
contains precious metals that serve
as catalysts, promoting chemical
reactions to convert the exhaust
gasses without af f ecting the metals.
The catalytic converter is ref erred to
as a three-way catalyst, since it acts
on HC, CO, and NOx. A replacement
unit must be an original Acura part
or its equivalent.
The three way catalytic converter
must operate at a high temperature
for the chemical reactions to take
place. It can set on f ire any com-
bustible materials that come near it.
Parkyourvehicleawayfromhigh
grass, dry leaves, or other f lamma-
bles.A defective three way catalytic
converter contributes to air pollution,
and can impair your engine’s per-
f ormance. Follow these guidelines to
protect your vehicle’s three way
catalytic converter.
Always use unleaded gasoline.
Even a small amount of leaded
gasoline can contaminate the
catalyst metals, making the three
way catalytic converter inef f ective. Keep the engine tuned-up.
Have your vehicle diagnosed and
repaired if it is misf iring, back-
f iring, stalling, or otherwise not
running properly.
Three Way Catalytic Converter
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291
THREE WAY CATALYTIC CONVERTER
WARM UP THREE WAY CATALYTIC
CONVERTER

If you take your vehicle f or a state
emissions test shortly af ter the
battery has been disconnected or
gone dead, it may not pass the test.
This is because of certain ‘‘readiness
codes’’ that must be set in the on-
board diagnostics f or the emissions
systems. These codes are erased
when the battery is disconnected,
and set again only after several days
of driving under a variety of
conditions.If the testing f acility determines that
the readiness codes are not set, you
will be requested to return at a later
date to complete the test. If you must
get the vehicle retested within the
next two or three days, you can
condition the vehicle f or retesting by
doing the f ollowing.
Make sure the gas tank is nearly,
but not completely f ull (around
3/4).
Make sure the vehicle has been
parked with the engine of f f or 8
hours or more.
Make sure the ambient
temperature is between 20° and
95°F. Without touching the accelerator
pedal, start the engine, and let it
idle f or 20 seconds.
Keep the vehicle in Park. Increase
the engine speed to 2,000 rpm, and
hold it there until the temperature
gauge rises to at least 1/4 of the
scale (about 3 minutes).
St at e Emissions T est ing
T esting of Readiness Codes
292

Select a nearby lightly traveled
major highway where you can
maintain a speed of 50 to 60 mph
(80to97km/h)foratleast20
minutes. Drive on the highway in
D. Do not use the cruise control.
When traffic allows, drive for 90
seconds without moving the
accelerator pedal. (Vehicle speed
may vary slightly; this is okay.) If
you cannot do this f or a
continuous 90 seconds because of
traf f ic conditions, drive f or at least
30 seconds, then repeat it two
more times (for a total of 90
seconds).
Then drive in city/suburban
traffic for at least 10 minutes.
When traf f ic conditions allow, let
the vehicle coast f or several
seconds without using the
accelerator pedal or the brake
pedal.If the testing f acility determines the
readiness codes are still not set, see
your dealer.
St at e Emissions T est ing
T echnical Inf ormation
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