2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 422Get this manual
IGNITION SYSTEM IGNITION PULSE GENERATOR PEAK VOLTAGE Check that the cylinder compression is normal and the spark plug is installed correctly in the cylinder headSeal the ECM connector with tape to prevent dirt and oil from entering the connector after disconnecting the 21P (Black) connector
Disconnect the 21P (Black) connector from the engine control module (ECM)
21P (BLACK) CONNECTOR
When reconnecting the ECM 21P (Black) connector, check that there is no dirt and oil in the connector
Be careful not to bend the connector terminals
Connect the peak voltage tester or adaptor probes to the Blueyellow terminal of the wire harness side 21P (Black) connector and groundCONNECTION: Blueyellow (+) Body ground () Shift the transmission into neutralTurn the ignition switch to ONCrank the engine with the starter motor and read the ignition pulse generator peak voltagePEAK VOLTAGE: 0.7 minimum If the voltage measured at the ECM 21P (Black) connector is abnormal, measure the peak voltage at the alternator connectorRemove the recoil starter cover (page 2-4)Disconnect the alternator 5P (Natural) connector and connect the peak voltage tester or adaptor probes to the Blueyellow terminal of the alternator side connector and groundIn the same manner as at the ECM connector, measure the peak voltage and compare it to the voltage measured at the ECM connector If the peak voltage measured at the ECM connector is abnormal and the one measured at the alternator connector is normal, the Blueyellow wire has an open or short circuit, or loose connection If both peak voltages are abnormal, follow the checks described belowCheck the ignition pulse generatorCheck the stator11-8 for