AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 102)

Page 102 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
When the “teeth” on a toothed wheel pass by a sensor, the sensor creates a voltage pattern that
is used by the ECU for many important calculations. The example above shows two different
toothed wheels, one that rotates with the crankshaft. The other rotates with the camshaft (1/2
engine speed). Representative voltage signal patterns for one complete engine cycle (2
revolutions) are also shown. The calibration file must contain the proper settings to define this
pattern for the ECU.
In most cases, AEM will provide either a base calibration or a crank and cam sensor
wizard that can be used to define these settings.
It’s important to understand some
basic concepts though, especially if there are problems to troubleshoot on universal
applications.
WARNING!
– Improper use of these settings can lead to engine
damage.
Many different crank and cam input configurations are possible with an AEM EMS. The diagram
above illustrates a very basic even tooth pattern along with fuel output phasing and spark output
phasing setups. The following crank and cam edge selection options are used in this example:
Crank Hall Rising Ed(ge) = ON, Define the rising edge of the crank sensor pattern as a
significant edge. A significant edge is defined as an edge that increments the fuel and spark
tooth counts.
Cam Hall Rising Edge = ON, Define the rising edge of the cam sensor pattern as a significant
edge. When this edge is detected, the Cam Tooth channel will increment.
All other edge selections are turned off. The “MAG” edge settings (EMS-4 applications only) are
used for VR or magnetic type sensors. They are completely independent inputs. See pinout
sheet or schematic for more information.