The check engine icon lights up for 4 seconds during the diagnostic part of the ECM boot-up when the ignition switch and kill-switch are turned on. When you crank the bike, sometimes the battery voltage drops enough to restart that process so the light comes on again.... for 4 seconds... not to worry. If there is an actual problem code (DTC), then the light comes BACK on for either 8 seconds or permanently, depending on if the code is historic or current.
A seperate process is the ECM activates the 'system relay' for 2 seconds which operates the fuel pump... when the key is first turned on to pressurize the fuel rail for starting, but not to operate the pump needlessly if the bike doesnt get started right up. Then when the Crankshft Position sensor (CKP) tells the ECM the bike is starting, the pump gets turned back on.
Hope that helps....... relax bud. :mrgr: