Yamaha F150B Service Manual

Also see for F150B: Owner's manual Service manual Owner's manual

4-4Troubleshooting the power unit012345678910ATroubleshooting the power unitTroubleshooting procedure1. Before troubleshooting the outboard motor, make sure that fresh fuel of the specified type hasbeen used.2. Check that all electrical connections are tight and from corrosion, and that the battery is fullycharged to 12 V.3. Check the trouble code using the YDIS first, and then check the electronic control system followthe trouble code chart.4. When a trouble code is detected, check the data logger of the engine ECM record data graph aswell.5. If a trouble code is not detected, check the power unit according to “Troubleshooting the powerunit (trouble code not detected)” (4-11).6. Before using the YDIS to check the power unit, check the engine ECM circuit. To check theengine ECM circuit, see “Checking the engine ECM circuit” (5-15).TIP:• Make sure to check that the couplers and connectors are securely connected.• When deleting the diagnosis record on the YDIS, make sure to check the time that the troublecodes were detected.• When checking the input voltage of a part, the coupler or connector must be disconnected. As aresult, the engine ECM determines that the part is disconnected and a trouble code is detected.Therefore, make sure to delete the diagnosis record after checking the input voltage.• Since the main relay comes on for approximately 10 seconds after the engine start switch isturned to “OFF,” the power of the engine ECM cannot be turned off. Therefore, if the engine startswitch is turned to “ON” within 10 seconds after it was turned to “OFF,” the trouble codes cannot bedeleted.Troubleshooting the power unit using the YDIS1. Use the trouble codes displayed by the YDIS to check each part according to the “Trouble codeand checking step” table.2. Delete the trouble codes after checking, repairing, or replacing a part and check that the troublecodes are not detected again. If the same trouble codes are detected, the engine ECM may befaulty.3. Check the items listed in the table, if all the items are in good condition, and delete the troublecode, and then check the trouble codes again. If the same trouble codes are detected again, theengine ECM is faulty.YDIS / Troubleshooting the power unit