https://docs.emtronaustralia.com.au/engine-management/config/triggers/crank-index-offset-setup/index.htmlCrank Index Offset Setup The Crank Index Offset Setup is a critical configuration step. It is the point in which the ECU has latched onto the “timing” of the engine as a reference of TDC #1 Compression. Depending on the trigger decoding mode selected, the ECU will latch onto a an “Index Tooth”, and this Index point generally does not reference TDC (Top Dead Center) cylinder #1 compression. The Crank Index Offset Position is what allows the ECU to offset the Index Tooth position to allow the ECU to keep time the engine appropriately.Hugoen-us