december2022 - A20

LEARNING TOOLS
720-degree engine cycle. Here are just a
few of the benefits:
* Comparison of piston position and
direction of travel, from cylinder to
cylinder
* The firing order is always displayed
* Valve overlap periods
* Top Dead-Center points/ignition events
The piston chart is plotted either
superimposed on the existing waveform
or above/below the existing waveform.
Implementing it is as simple as opening
a new window on your PC. Regarding
the return on investment, the tool typically
pays for itself the very first time
it is implemented.
SERVICE INFORMATION
Many technicians and shops in general
take service information for granted.
There is a lot more to it than simply
referencing removal and installation
instructions, labor time guides, or diagnostic
flow charts. Adequate service
information can yield a diagnostician
a boatload of know-how without ever
leaving the workbench. The following
are some of the search criteria I
frequently reference:
1. System description/operationWe
all know that each vehicle may be
configured differently. This means
there are multiple ways to accomplish
the same intended goal and multiple
options for system configuration. Having
access to this piece of the diagnostic
puzzle is priceless. Establishing a game
plan before approaching the vehicle is
what it takes to stay efficient and accurate.
Avoid the pitfalls that so many
encounter when they don't take the time
to research this important piece of information.
Approaching the vehicle without
anticipation of what is supposed to occur
(under certain operating conditions) is a
recipe for misdiagnosis and/or expensive
and embarrassing comebacks.
2. Wiring diagrams- Like what was
just stated above, each vehicle has the
20 DECEMBER 2022 VehicleServicePros.com
3. Flowcharts- I use diagnostic
Overlay software like the ETO by
" The Driveability Guys " offers an easy-to-view
piston chart to help identify engine-mechanical
faults without disassembly.
flowcharts like many of us technicians
do. However, I implement them
differently. I choose not the follow the
flowcharts, word for word. In fact, if I
encounter a step in the diagnostic flow
chart procedure that does not make
sense to me, I do not proceed with that
test. It's simply because I wouldn't
know how to anticipate the results. I use
flow charts for bits of data that only the
manufacturer's engineers would know
(they designed the systems). I will reference
the flow charts to understand the
thresholds or when the ECU determines
there is a fault present. Understanding
what the ECU desires is part of the
diagnostic process.
Other pieces of data like resistance
The need for relevant service information
is always present as it gives the technician
information required for a proper analysis.
potential to be configured differently.
For instance, depressing a horn pad
may energize a relay to allow for a horn
to sound. However, that same horn pad
on a different vehicle may provide a
ground path (but not for the relay) for
a signal circuit to an electronic control
unit (ECU). That ECU may send
that horn request to another ECU on
the network. It is the job of that second
ECU to energize the horn relay.
After all, the horn sounds the same in
either configuration. Having access to
and choosing to reference that system
wiring diagram, in combination with
the system description and operation
will allow you a few benefits:
* Identify system configuration and
functionality
* Develop anticipation of the test
results before approaching the
vehicle
* Determine the best testing locations
with the least amount of invested time
specifications or rate of pressure leakdown
(and such) are desirable to be
aware of as you will then know how
to interpret the test results. Not having
access to this information will
leave you guessing and either have you
replacing components for no reason or
allowing a failing component or system
to slip right past you.
THE DIAGNOSTIC PUZZLE
Being able to provide solutions to diagnostic
challenges is something most of
us will have to face at some point in
our careers. Solving these diagnostic
dilemmas is only one part of the equation.
Doing so in a timely fashion is
the other.
We can choose to have diagnostics
as a hobby or a career. The main
difference between the two options
is efficiency. The examples above
are just a few of the tricks I have up
my sleeve. Be creative in the way you
choose to implement your tools. They
will likely serve you well and give you
a more solid understanding of what
is truly occurring in the systems and
components you are forced to address
each day.
http://www.VehicleServicePros.com
december2022

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