MACS Monthly Newsletter - 2019 - AUG4

Factory Scan Tools on Your PC
scan tool (i.e. Snap-On, Autel, Bosch, Launch, OTC,
etc.) may have allowed you to relearn an HVAC
blend door or even set an offset correction factor on
an Automatic HVAC system.
On the other hand, most techs who've used an aftermarket scan tool for very long will be able to share
their frustrations on these types of "bi-directional"
functions where the scan tool goes well beyond retrieving DTCs and displaying PIDs (Parameter IDs
a.k.a. "live data") for routine diagnostics. More frequently than we like, there is a relearn procedure that
just doesn't work when we connect our favorite enhanced "dealer level" aftermarket scan tool.
I recall one such feature with a PC based aftermarket tool I was using to assist an aftermarket
repair shop in completing a big-ticket job on a
late model Dodge Magnum with a V8 Hemi. The
shop owner had installed numerous parts and performed numerous services on the vehicle to correct
a drivability complaint. The last item the shop had
installed was a PCM. This PCM installation and
software programming had no problems allowing
the vehicle to start revealing that they didn't have
an immobilizer issue as some Dodge diesels do after a PCM flash. However, the car 's MIL came on
with a DTC pointing to the need for an idle (throttle by wire) relearn. Without the relearn properly
performed the throttle was in default / limp home
mode, meaning nobody was going to drive this
Hemi over 10 MPH for the time being. The particular scan tool I was using (a Delphi co-branded
Blue Streak Electronics OTTOTEST) clearly showed
the throttle relearn procedure in the tool's menu
options, but when the procedure was attempted
it just clocked and clocked and finally timed out
unsuccessful. The company was quick to answer
their support line and get the right expert on the
phone to verify the tool had a problem and not the
car. Literally while I was taking the shop owner to
lunch, Blue Streak was able to figure out the software bug and download a software update to my
tool / PC over the internet. We did the idle relearn,
cleared the DTC, performed a successful road test
and called the customer to advise them that their
car was ready for pick up!
On the other hand, personal experience and hundreds of testimonies shared with me by other techs
and shop owners has proven this type of scan tool
patch / update to correct a deficiency in nearly real
time is more the exception than a rule. ■

When you hear the word "java" do you think
Starbucks or Folgers? Do the words "license" and
"registration" bring back memories from the last
traffic ticket you received? Chances are you answered yes to both questions. On the other hand, if
your mind immediately referenced those terms related to today's IT (information technology) world,
you might possibly be able to skip this portion of
this month's MSR. Otherwise - read on!
Most likely you've been using your PC (personal
computer) to look up TSBs and repair manuals for
close to two decades now. A few readers are also
likely versed in programming modules by now. If
you're in that category - congratulations! You're
truly in a unique minority and have had to come to
grips with many IT-type challenges related to auto
repair, above and beyond simply maneuvering the
web to search for repair information. Today, electronic programming (a.k.a. module "flashing") in
some shape or form is required as part of the installation of most electronic ECUs. Furthermore, the
need to update software in a fully operative existing ECU on the vehicle in order to correct a performance issue is becoming very common place. There
is, however, a lot more use for your PC beyond the
world of module programming. As I worded in my
previous statement, "programming / flashing in
some shape or form" that includes minor software
changes that do not require a factory scan tool or
J2534 reprogramming tool.

Terms Matter
Certain relearn functions performed by a scan
tool are tasks that most readers will agree are not
"IT intensive". They include tasks such as relearns
and configuration settings required after 12-volt
battery resets such as steering angle sensor and
power window (auto power up) relearns.
There may also be items initiated by your scan
tool after a module replacement and required software programming procedures are performed.
Examples of the latter would include cam/crank
variation relearns and idle relearns. These types
of procedures do not fall into the same category
as "module flashing, module programming and
module coding" which require a subscription to a
particular OEM's calibration database and either a
factory scan tool or a J2534 universal pass through
device. Your enhanced "dealer level" aftermarket

August 2019

MACS Service Reports

MACS Monthly Newsletter - 2019

Table of Contents for the Digital Edition of MACS Monthly Newsletter - 2019