YANMAR Marine Engine Trouble Shooting
YANMAR Trouble Shooting: Possible Cause, Possible Remedy
No response from starter motor
No battery voltage to starter - Verify wiring and battery connection (power and ground)
Battery discharged - Charge or replace battery, verify alternator charging
Tripped overcurrent protection - Correct fault, replace or reset overcurrent protection
No signal from control system - No power to control system
Defective starter solenoid - Replace starter solenoid
Defective starter motor - Replace starter motor
Engine will crank but not start
Engine not getting fuel - Check fuel level, filter, fuel pump, verify no air in fuel lines
ECU is not functioning - See Engine Troubleshooting
Tripped overcurrent protection - Correct fault, replace or reset overcurrent protection
No preheat (cold condition) - See Preheat Troubleshooting
Engine runs and shuts down
ECU shutdown - Use display to view ECU diagnostic codes, use ECU diagnostic tool for more detailed information
Circuit overload protection tripped - Correct overload, keep control system from overheating (over 167° F or 75° C)
Voltage transients (spikes) - Add suppressor diodes, protect from nearby lightening strikes, shield induced spikes from other equipment, add electric motor control relay
Defective control system - See Control System Troubleshooting
Alternator not charging battery
Broken or slipping alternator drive belt - Adjust or replace alternator drive belt
Alternator not excited - Verify excitation circuit connected, replace faulty regulator
Alternator output not connected - Install charge wire
Alternator not grounded - Clean or add ground connection
Alternator faulty - Replace faulty alternator
ECU does not power-up
No power to ECU - Locate reason for lack of power and correct (Circuit overloaded? Failed suppressor diode? Faulty wiring?)
Tripped overcurrent protection - Correct fault, replace or reset overcurrent protection
Faulty ECU - Replace ECU
Optional e-stop engaged - Disengage e-stop
Engine not getting fuel
Empty fuel tank - Fuel engine
Clogged filter - Replace filter
Air in fuel lines - Bleed fuel lines
Low fuel pressure - Replace faulty fuel pump and/or clogged filter
Faulty fuel pump - Replace fuel pump, correct wiring fault (electric fuel pump)
Engine is hard to start in cold conditions
Start attempt before preheat complete - Wait for preheat time to elapse, crank as soon as time elapses
Heater faulty - Replace heater
Heater relay faulty - Replace relay
Preheat control not functioning - Correct wiring, correct ECU configuration
Faulty control system - Repair or replace ECU
Engine produces excessive white smoke after starting
Afterglow not enabled - Reconfigure ECU
Heater faulty - Replace heater
Heater relay faulty - Replace relay
Preheat control not functioning - Correct wiring, correct ECU configuration
Faulty control system - Repair or replace ECU
Control system does not perform self test
Tripped overcurrent protection - Correct fault, replace or reset overcurrent protection
Faulty connection to battery - Correct battery connections
Faulty control system - Repair or replace control system
Control system performs normal self test, engine cranks, runs and shuts down
Engine Stop LED illuminated - Correct ECU stop condition, use ECU diagnostics
Display does not display data
Display lost power - Turn on key, verify display plugged into harness
Engine Source address incorrect - Change Engine Address in Configuration
Display Address incorrect - Change Display Address to 40 (default)
Display configuration problem - Reset display using Restore Defaults
CANbus failure - Check CANbus
ECU not sending data - Repair or replace ECU