[DeTomaso] [NPC] OBD2 Code Scanners - Findings

[Mark McWhinney]

I have been reading up a lot on the OBD and OBD2 ports.  Although they were
mandated by the EPA for checking the emissions systems, there is a wealth of
other diagnostic and performance information available via the ODB2 port
that is on all domestic and most foreign cars made since the 1996.  The
original OBD ports were used prior to 1996, but the implementation varied
from one manufacture to another.  The new CAN standard will be mandated in
2008.

One guy went poking through his computer on his Jeep to improve gas mileage
and found a lot of interesting information about the interplay of air
density, temperature, ram air boost, horsepower, and acceleration which he
wrote up in an article at.
http://www.omninerd.com/2006/07/16/articles/57


>From what I can tell, there are three basic ways to get information from a
port:

1) A code reader can simply display the code letter/number which you go look
up in a book or on-line.  They may be a simple LED display on the end of a
cable or may be a handheld device with an LCD display.  These are generally
under $50 and available at all parts stores.  For future reference, these
are the generic and manufacture-specific trouble code definitions.
http://www.obd-codes.com/trouble_codes/index.php
The "P" codes are for the power train.  B is for Body, C for chassis, etc.

2) A code scanner can not only display the current code and its definition
but also can display the code and statuses of many other devices in the car.
They can also provide sensor readings such as the O2, MAP, and oil temp.
They higher high scanners can do freeze frame to capture a sequence of
readings over time. Most scanners can reset the Check Engine light.  They
are hand held devices with multi-line LCD displays They run from $100 to
$700 where more info => more money.  Many parts stores are these.

3) The other type is an adapter with a cable that hooks up to a lap top, Mac
or Palm using a serial, USB, or even Bluetooth connection.  This provides
access to all the information.  There are several free and commercial
programs that can analyze and display the information.  The cost runs from
$100 to $200 which is $100 for the adapter and cables and $0 to $100 for the
software.  I have only found them on-line.

List of software available:
http://www.scantool.net/?mode=browseSoftware

Interesting screen shots (Diagnostics)
http://www.myscantool.com/images/screenshots/TroubleCodes_Large.gif
http://www.myscantool.com/images/screenshots/Scope_Large.gif
http://www.palmerperformance.com/screenshots/new/pcmscan_gauges.png
http://www.palmerperformance.com/screenshots/new/pcmscan_custom_dash.png
http://www.palmerperformance.com/screenshots/new/pcmscan_monitor_status.png

Interesting screen shots (Performance)
http://www.myscantool.com/images/screenshots/TrackPerformance_Large.jpg
http://www.myscantool.com/images/screenshots/Dyno_Large.jpg
http://webpages.charter.net/eecanalyzer/ScreenShots/DragStrip.htm

Interesting screen shots (Other)
http://webpages.charter.net/eecanalyzer/ScreenShots/CamSpecs.htm
http://webpages.charter.net/eecanalyzer/ScreenShots/Speed.htm



Last night I drove my Ranger over to Chuck Melton's place.  His friend
brought over a code scanner.  I popped the cover all the OBD2 port which was
just below and to the drivers' left of the steering column,  The cable
pushed right in, and the scanner fired up without a hitch.  The four line
LCD display guided me through the set up and reading process.

The results:

P0756 mod $10
Shift solenoid B
Check performance or
Stuck off

It sounds expensive, but it appears to have been a one time problem.  I had
the tool reset the code and have not had a problem today.