Currently, the EVAP system is the only one listed here. If the vehicle you are working on supports this function, you can
use it to "command" the PCM to seal the EVAP system for you, rather than worrying about which hose to plug before you pressure
test and/or smoke test the sys-tem. Cycle the key to return the EVAP system to normal if you do use this function. MODE $09: VEHICLE VIN AND PCM CALIBRATION How many times have you had a driveability issue and found a technical service bulletin (TSB) suggesting a reprogramming of
the PCM? Very often, the bulletin will list the old calibration number and the new one. Use this mode to see if that "reflash"
has been done. 
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One last review point: Generic OBD does not support all nine modes. Look for Global OBD2 on your scan tool's menu.
LET'S EXPERIMENT I have been curious about Mode $06 for quite a while. While recently working on a 2001 Ford Explorer with an intermittent
MIL complaint, I decided to scroll through the test results to see if anything stood out. Before you access the individual tests, first check the monitor status in Mode $01. If the monitor(s) show "not complete"
or "not ready," the individual test results may or may not be valid. See Figure 2. In addition, a monitor will not complete if there is a fault in another system that it needs to complete its own testing.
For example, a faulty oxygen sensor will prevent the catalyst efficiency monitor from running. Also keep in mind that once all monitors are complete, they will stay that way unless they are cleared or battery power to
the PCM is lost. Last, a completed monitor does not mean that the tested system is OK, only that the conditions needed to
run the tests were met. When you access Mode $06 test results with most scan tools, you'll see something like this. TID $2B CID $00 MEASURED: 34007 MINIMUM: 35238 MAXIMUM: NA There will also be a "passed" or "failed" statement. "TID" stands for "test identification" and "CID" stands for "component
identification"; CAN vehicles use MID (monitor ID) and TID (test ID). The number values are "computer" values and mean nothing
to me as a tech. In this example, the hexadecimal values have already been converted to decimal values. A few scan tools will
report the hexadecimal values only. You'll need a scientific calculator to convert the numbers to decimals. There is one on
most Windows desktops. What does stand out in this example is the fact that the measured value is out of range and the test
is listed as "failed." See Figure 3. This is the first drawback to Mode $06. Without the means to translate the information, it's useless. The good news is that
a few scan tools translate this information for you. Another plus is the readily accessible factory service information on
the Internet. Some manufacturers provide Mode $06 data for free, others charge a nominal fee. You can find these sites listed
at http://www.nastf.org/. In addition, there are aftermarket publications that have already compiled this information into one handy reference, and
don't forget other Web resources, such as iATN. If you dig deep enough, you'll find informational factory TSBs that explain how their monitors work. This may seem like a
lot of effort, but let's face facts. This industry changes rapidly and keeping up is the smart thing to do. As a professional,
continuing education is part of the job. But you already know that.
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