AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 32)

Page 32 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
Shows signal conditioning with edge
invert on typical evenly spaced VR
crank pattern.
Internal Signal Conditioning Detail
All VR Crank Sensor inputs to the EMS-4 must be connected such that the rising edge of the
raw sensor signal is the consistent zero crossing edge as shown in the examples above.
Failure to do this could result in misfires or ignition timing inaccuracies. Verify data with an
oscilloscope or contact your sensor manufacturer to verify polarity. The crank inputs to the
EMS-4 are contained within a black shielded cable assembly as shown below. Refer to the
EMS-4 System Diagram for more information.
Crank Sensor Input Cable End