Yamaha F150B Service Manual

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

4-8Troubleshooting the power unit012345678910A27 Water in fuel Water in fuel W/F Alert buzzer goes out when enginestarted—1. Check for water in fuel filter. —2. Measure the water detectionswitch input voltage.5-23A-33. Check the water detectionswitch for continuity.5-234. Check for wiring continuitybetween the water detectionswitch and engine ECM.5-23A-328 Shift positionswitch malfunc-tionIrregular signal C/E— —1. Check the gear shift opera-tion.10-132. Measure the neutral switchinput voltage.5-37A-53. Check the neutral switch forcontinuity.5-374. Check for wiring continuitybetween the neutral switchand engine ECM.5-37A-529 Intake press sen-sor malfunctionOut of specifica-tionC/E Higher idle speedDegraded acceleration performanceDeclining maximum engine speed—1. Measure the air pressuresensor input voltage.5-32A-52. Measure the air pressuresensor output voltage.5-32A-53. Check for wiring continuitybetween the air pressuresensor and engine ECM.5-32A-537 Intake air pas-sage malfunctionAir leak C/E Higher idle speedOver-revolution at fully opened throt-tle—1. Check the O-rings and gas-kets of the intake silencerand intake manifold.6-166-272. Check the intake manifold forcracks.6-273. Check the vacuum hose. 6-324. Synchronize the throttlevalves.6-23Troublecode Item Condition Lan gaugedisplay Symptom Remarks Checking steps Refer topage