Motorcycles have come a
long way in recent years and with the new technology the
need for test equipment, especially in the electrical
department is critical.
When the engine check
lamp comes on the anxiety attacks start. Though the
factory calls it an engine check lamp and it monitors
the engine control module (ECM) it also handles the
instrument module (IM) and the turn signal/security
If you have a 2001-2008
H-D fuel injected model using the Delphi fuel injection
system or 2003-2006 Harley carbureted model with the new
12-pin ignition model the motorcycle has the SAE J1850
Data bus you are good to go.
Daytona Sensors has come
out with a low cost scan tool named the “Twin Scan II”
that will take the guess work out of why the light came
on. The tool connects to the 4-terminal Deutsch style
data link connector in the Harley wiring harness, which
is usually near the engine control module. On the Harley
Road King motorcycle being used in this article, it is
under the right side cover behind the saddlebag.
This shot shows the
You will need a computer
preferably a laptop for data display. Once everything is
connected simply go to View Diagnostic Trouble Codes.
Click on the read codes button to see all the available
modules. The lower half of the screen will show the
Scanner plugged into your
Look for the trouble code
up in the Harley Electrical Diagnostic manual for your
model. You can then follow the trouble shooting
flowcharts to determine exactly what component is
defective. In many cases I have found it to be a loose
or dirty connection easily repaired by a little
electrical contact cleaner and tightening the
connection. You can then clear the trouble codes using
the tool. If the light comes back on then you know the
part is defective and can replace it yourself or have it
Another great feature is
that you can install the unit and ride the motorcycle
without it hooked to the laptop and it will store
information for up to one hour. This is very helpful
when you have intermittent trouble codes that do not
appear during shop run tests. After your road test you
can download the data and examine what happened before
and after the code was set.
An added feature is the
Real Time Engine Data Display where tachometer,
speedometer, battery voltage, cylinder head temperature
and various functions of the fuel injection system such
as throttle position, manifold pressure, intake air
temperature and idle control stepper can be observed.
Depending on the engine control unit your motorcycle is
using, you can also check your air to fuel ratio which
with today’s fuel prices is something we are all
The Twin Scan II is also
an ideal tuning aid for use with the Harley Screamin
Eagle Race Tuner (SERT), Dynojet Power Commander, or
Daytona Twin Tec Twin Tuner.
It comes with very
detailed instructions and Excellent Tech Support.
Suggested retail is Only $185.00
For more information or
to order contact Daytona Sensors, 933 Belville Road,
Suite 101-1, South Daytona, FL. 32119. 386- 322-7390
very happy with mine and so is one of my friends who
just saved a lot of money because he did not have to
take his motorcycle to a shop.
Motorcycle Hall Of Fame Member 2005