Automotive Computer Diagnostics start at $29.95
Yes, vehicles have computers and
plenty of them. Since the late eighties computers have taken on greater
roles every year in our vehicles to a point now where they have become
vital. While to many of us computers and internet access are part of
our daily work, we can still live and work without them until they're
back online. If a vehicles computer, commonly referred to as an ECM
(Electronic Control Module) or BCM (Body Control Module), is down or
doesn't function correctly, the vehicle may run poorly, may not pass an
emissions test, the windows and locks may malfunction or worse, it may
not start and run at all. That's because these days all major functions
of an automobile are controlled, and monitored, by computers on their
own networks. If something goes wrong with the vehicle, the computer
will know and possibly record a fault code long before the MIL
(Malfunction Indicator Lamp) comes on. Some issues are simple and can
be taken care of next time you visit D and R Car Care and Lube Center
for a service. Others are not and, if unchecked, can damage or destroy
the vehicles engine. Unlike your home computer, your vehicles
computers data cannot be seen on just any monitor. However, there is a
way to retrieve your vehicles stored computer data, with automotive
diagnostic equipment at Johnny's Complete Car Care .
OBD: On Board Diagnostics
When
computers began appearing in cars, the auto industry realized that
standardization was needed. In the 1980s the Society of Automotive
Engineers (SAE) came up with OBD, On Board Diagnostics, diagnostics
data variables with a relatively standard connector plug. OBD's mission
was to reduce emissions, make sure failures could be discovered and
fixed quickly via good diagnostics. Those standards were adopted by the
very stringent CARB (California Air Resources Board) in 1985 and
applied in 1988. They primarily checked the proper functioning of a few
components and circuits related to emissions. Unfortunately, the
original OBD standard was unable to identify a potential problem until
it actually happened or a component completely failed, and by then it
was too late. Learning from OBD, the first standard, OBD-II is an
expanded set with much more standardization both in connectors and
fault codes. OBD-II was adopted by CARB in 1989 and later by the EPA
(Environmental Protection Agency). Starting in 1996, every vehicle sold
in the US is required to have a computer that can generate the OBD-II
codes and a standard OBD-II connector. Now OBD-II is a worldwide
standard. Internationally, OBD is handled by the ISO (International
Organization for Standardization). As a result, every car can
accommodate the same DLC (Data Link Connector) and generates the same
generic DTC (Diagnostic Trouble Codes).
Generic and Enhanced Codes
To make things a bit more
complicated, Diagnostic Trouble Codes can either be "generic," common
codes used by all manufacturers, or "enhanced," codes used only by
specific manufacturers. General Motors, Ford, and Chrysler all have
their own set of enhanced codes. A standard OBD-II scan tool can read
all those codes, but not necessarily interpret them as they may apply
to a single vehicle of a particular model year.
Automotive Networks
There are also different Data
Communication Network Interfaces (DCNI) for vehicles. In the US, SAE
specifies "Class 2" J1850 VPW Variable Pulse Width (GM) and "SCP" J1850
PWM Pulse Width Modulation (Ford). Internationally, the ISO specifies
the "K-line" 9141-2 standard (also used by Chrysler) and on newer
vehicles the "KWP2000" 14230-4 standard. The Canadians use yet another
standard. Not all of these protocols use the same pins on the
connector, and sometimes, by a trained technician, it is possible to
determine the protocols just by looking at what pins are present.
Data Link Connectors
The
car's Data Link Connector, also called a female SAEJ1962 is generally
located under the dash on the driver side, a foot or so away from the
center of the dash. A diagnostic scan tool plugs into the DLC to read
the codes generated and either displays them on its own LCD or passes
them on to a more sophisticated computer.
OBD-II Scan Tools
The
task of a scan tool is to interface with one or more of those
automotive data communication network interfaces and read the codes
stored in the current fault database and in the fault history database,
assist in interpreting the codes meaning and clearing them from the
database in order to turn of the MIL. A popular scan tool among
automotive shops is the Snap-On® Solus™ Scanner™. A bit more
sophisticated scan tool and lab scope combination is the Snap-On®
Modis™, which is what we at Johnny's Complete Car Care Center use for
retrieving diagnostic trouble codes and checking your vehicles
ignition system. With the Modis™ we are capable of not only reading
diagnostic trouble codes and checking your ignition system but we can
also trigger certain functions on your vehicle by turning them on and
off. The Modis™ can operate your electric windows, electronic door
locks, windshield wipers and washer pump, headlights, flashers, idle
your vehicle up or down and even shift the gears in your vehicles
automatic transmission just to name a few. These functions help Johnny's Complete Car Care Center troubleshoot automotive diagnostic problems
related to your vehicles ECM or BCM.
With computers, so much a part of
todays vehicles, the mechanics of years ago are now highly trained and
certified technicians. Come see the highly trained and certified
technicians at Johnny's Car Care Center today, and let us help
you with your vehicles diagnostic needs.
