2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 301Get this manual
IGNITION SYSTEM Disconnect the alternatori gnition pulse generator 4P (wh itel connector and connect the peak voltage tester or adaptor probes to the ignition pulse generator side connector term inalsCONNECTION: Blueyellow (+1Green (-) In the same manner as at the leM connector, measure the peak voltage and compare it to the voltage measured at the leM connector If the peak voltage measured at the leM is abnormal and the one measured at the ignition pulse generator is normal, the wire harness has an open circuit or loose connection If both peak voltages are abnormalfollow the checks described the troubleshooting chart (page 17-41