Haltech E6X Manual Win Version User Manual
Page 146
E6X Manual
146
E.5 Synchronisation
When the ECU is configured to operate an engine that uses direct fire ignition or sequential
injection, the ECU needs a reference for engine position often referred to as a “synchronising”
signal or a “home” signal.
When the ECU is configured to perform full sequential injection or full direct fire ignition it
requires a home signal that occurs once in the full cycle (720° of crank rotation and 360° of
cam rotation). If the ECU is configured for waste spark direct fire the ECU requires a home
signal that occurs once in the half cycle (360° of crank rotation).
On a distributed engine the ECU does not need to know the engine position, it simply
generates a spark that is mechanically distributed to the correct cylinder. Direct Fire ignition
systems need to know which cylinder to fire next. The same principles of timing and
sequence apply to sequential injection. When the ECU sees a home signal it assumes that the
cycle for ignition and injection has restarted.
1
4
1
2
3
1
4
1
2
3
Trigger Events
Home Signal
Trigger signal
Cylinders -
(Order of Fire)
Permissible
window for
Home Signal