Yamaha YZ250FM 2021 Owner's Service Manual

FUEL INJECTION SYSTEM8-26Fault code No. 30TIPBefore troubleshooting, disconnect the starter motor lead from the starter relay.5 Defective intake air tempera-ture sensor.Execute the diagnostic mode.(Code No. 05)When the machine is cold, dis-played temperature is close tothe ambient temperature.Improper display  Replace theintake air temperature sensor.Start switch to ON (main relayON), and then check the condi-tion of the fault code using themalfunction mode of theYamaha diagnostic tool.Condition is “Recovered”  Goto item 7 and finish the service.Condition is “Detected”  Go toitem 6.6 Faulty ECU. Replace the ECU. Service is finished.7 Delete the fault code. Confirm that the fault code hasa condition of “Recovered”using the Yamaha diagnostictool, and then delete the faultcode.Fault code No. 30Item The vehicle has overturned.Fail-safe system Unable to start engineUnable to drive vehicleDiagnostic code No. 08Diagnostic tool displayDisplays the lean angle sensor output voltage.• 0.4–1.4 (V) (upright)• 3.7–4.4 (V) (overturned)Procedure Remove the ECU, and incline it 45 or more.Item Probable cause of malfunc-tion and check Maintenance job Confirmation of service com-pletion1 The vehicle has overturned. Raise the vehicle upright. Start switch to ON (main relayON), wait 10 seconds, thencheck the condition of the faultcode using the malfunctionmode of the Yamaha diagnostictool.Condition is “Recovered”  Goto item 4 and finish the service.Condition is “Detected”  Go toitem 2.2 Mounted condition of ECU.Check for looseness or pinch-ing.Check the mounted conditionfor correctness.Improperly mounted ECU Remount the ECU.Start switch to ON (main relayON), wait 10 seconds, thencheck the condition of the faultcode using the malfunctionmode of the Yamaha diagnostictool.Condition is “Recovered”  Goto item 4 and finish the service.Condition is “Detected”  Go toitem 3.Fault code No. 22Item Intake air temperature sensor: open or short circuit detected.