2006 Honda TRX680 Rincon Factory Service Manual, Page 137Get this manual
FUEL SYSTEM (PGM-FI) 2ECT Sensor Inspection Remove the fuel tank left side cover (page 3-6)Turn the ignition switch OFFDisconnect the ECT sensor 2P (Black) connectorTurn the ignition switch ON and engine stop switch "O"Check the ECT sensor with the HDS pocket testerIs about indicated? NO YESGO TO STEP 3- GO TO STEP 42P BLACK CONNECTOR
3ECT Sensor Resistance Inspection Turn the ignition switch OFFMeasure the resistance at the ECT sensor terminalsConnection: WhiteGreenred Standard: 2.32.6 kn (20C68F) Is the resistance within 2.32.6 knYES NoReplace the PCM with new one, and recheck- Faulty ECT sensorGR ECT SENSOR 2P (BLACK) CONNECTOR (Sensor side of male terminal)