Table of Contents
Advertisement
100-04-2
Noise, Vibration and Harshness
100-04-2
DESCRIPTION AND OPERATION
Noise, Vibration and Harshness (NVH)
Noise, vibration and harshness (NVH) is becoming
more important as vehicles become more
'
Know the History of the Condition
sophisticated and passenger comfort levels
increase. This section is designed to aid in the
-
Did it start suddenly or appear gradually?
diagnosis and testing and repair of NVH concerns.
-
Was it related to some other occurrence such
-
Noise is defined as sounds not associated with
as a collision or previous part replacement?
the operation of passenger compartment
-
Know how the condition made itself known; it
equipment that interface with customer
may be an important clue to the cause.
satisfaction.
-
Vibration is defined as impulses felt by the
customer that are not caused by road surface
Know the Probability of Certain
changes.
Conditions Develop~ng
-
Harshness is a ride quality issue where the
-
Look for the simple rather than the complex.
customer feels that the vehicle response to the
road surface is sharply transmitted to the
-
For example:
customer.
-
Electrical conditions usually occur at
connections rather than components.
Diagnostic Theory
-
An engine no-start is more likely to be caused
by a loose wire or small adjustment rather
than a sheared-off camshafi.
Diagnosis is more than just following a series of
interrelated steps in order to find the solution to the
-
Know the difference between impossible and
specific condition. It is a way of looking at systems
improbable. Certain failures in a system can be
that are not functioning the way they should and
improbable but still happen.
finding out why. Also it is knowing how the system
-
New parts are just that, new. It does not mean
should work and whether it is working correctly.
they are always good functioning parts.
There are basic rules for diagnosis. If these rules
are followed, the cause of the condition is usually
Do Not Cure the Symptom and Leave
found the first time through the system.
the Cause
Know the System
-
Know how the parts go together.
Lowering the pressure in a front tire may correct
the condition of a vehicle leaning to one side, but
it does not correct the original condition.
-
Know how the system operates as well as its
limits and what happens when the system goes
Be Positive the Cause is Found
wrong.
-
Sometimes this means checking the system
-
Double check findings.
against one that is known to be working
-
What caused a worn component?
correctly.
-
A loose transmission or engine mount could
indicate that other mounts are also loose.
Know the History of the System
Diagnostic Charts
A clue in any one of these areas may save time:
-
How old or new is the system?
Charts are a simple way of expressing the
relationship between basic logic and a physical
-
What kind of treatment has it had?
system of components. They help discover the
,.
-
Has it been serviced in the past in such a
cause of a condition in the least time. Diagnostic
(,-
manner that might relate to the present
charts combine many areas of diagnosis into one
condition?
visual display:
-
What is the service history?
2006.0 Fiesta
12/2006
G28448en
Hide quick links:
Advertisement
Table of Contents
