309-03125-0 Tohatsu FLOAT

Operator Information
* What happened, and when?* Under what conditions? Was the engine rpm (speed) high or low?Was the engine under load?* Are there any customer or dealer installed systems that could cause this symptom?* What else occurred?* When did the symptoms begin (and what else happened at that time)?LOGGED Diagnostic Codes
* Do they correlate to probable causes?* Did they occur at the same time as the symptoms?* Are some codes Logged repeatedly?Other Symptoms
* Are they related to this symptom?* Do they have common probable causes?Finally, test each probable cause using the tests suggested by the procedure. Be sure to check connectors, especially on intermittent problems! Refer to P-500: Inspecting Electrical Connectors for details.P-301: Engine Cranks But Will Not Start
Probable root causes:* Engine speed (rpm) signal* Engine Shutdown Input* Air Shutoff Valves* Fuel Supply* Rack Controls* Combustion Problem Perform the following tests:1. Engine speed (rpm) signal Use an Electronic Service Tool to verify the ECM is receiving a correct engine rpm signal. If rpm is erratic or incorrect, refer to P-522: Engine Speed Sensors. If unable to access engine status information, refer to P-310: Electronic Service Tool Will Not communicate With ECM.2. Engine Shutdown Input Use an Electronic Service Tool to verify the Shutdown (Run/Stop) Input status is set to RUN.3. Air Shutoff Valves Reset if necessary. Refer to Operation & Maintenance Manual and P-534: Air Shutoff Solenoid.4. Fuel Supply Verify fuel is present at the fuel return line while cranking. Check for excessive air in fuel. A 9U6872 Flow Sight Tube is helpful in determining the presence of air in fuel. Check fuel quality and for congealed fuel (wax) in temperatures below 0 °C (32 °F).5. Rack Controls Verify the rack controls are delivering sufficient cranking rack position. Refer to P-532: Rack Actuation System and P-531: Rack Position Sensor / Calibration.6. Combustion Problems Check for combustion problems (mechanical).P-302: Engine Starts But Stalls Immediately
Probable root causes:* Air Shutoff Valves* Low Oil Pressure* Fuel supply* Rack controls* Engine speed (rpm) signal* Electrical power supply to the ECM Perform the following tests:1. Air Shutoff Valves Check if Air Shutoff Valves are tripping. Refer to P-534: Air Shutoff Solenoid if Air Shutoff Valves are closing.2. Low Oil Pressure Use an Electronic Service Tool to monitor oil pressure status while the problem is occurring. Check for a 100-01 Low Oil Pressure Alarm. Also, Check for proper operation of any customer installed engine protection systems.3. Fuel Supply Check fuel supply for air in fuel, a plugged fuel supply, or return lines with congealed fuel (wax) in temperatures below 0 °C (32 °F).4. Rack Controls Refer to P-532: Rack Actuation System and P-531: Rack Position Sensor / Calibration.5. Engine speed (rpm) signal Refer to P-522: Engine Speed Sensors.6. Electrical power supply to the ECM Refer to P-501: Electrical Power SupplyP-303: Erratic Or Unstable Engine RPM
Probable root causes:* Rack Controls* Throttle Position Sensor* Engine speed (rpm) signal* Fuel Supply* ECM or Personality Module* Customer Installed Service Tool Connector Perform the following tests:1. Rack Controls Refer to P-532: Rack Actuation System and P-531: Rack Position Sensor / Calibration.2. Throttle Position Sensor Refer to P-502: Throttle Sensor.3. Engine Speed (RPM) Signal Refer to P-522: Engine Speed Sensors.4. Fuel Supply Check fuel supply for air in fuel, a plugged fuel supply, or return lines with congealed fuel (wax) in temperatures below 0 °C (32 °F).5. ECM or Personality Module Refer to P-520: ECM/Personality Module.6. Customer Installed Service Tool Connector Under certain conditions, an excessively long customer installed Service Tool Connector can pick up electrical noise that can cause unstable engine operation. Temporarily disconnect ATA data link wires at the J31 Customer Connector to determine if this is the cause.P-304: Poor Or No Response To Throttle
Probable root causes:* Active diagnostic codes* Cold Mode (normal operation)* Throttle position signal* Rack controls Perform the following tests:1. Active diagnostic codes Troubleshoot any ACTIVE or LOGGED diagnostic codes.2. Cold Mode Verify that the ECM is out of cold mode.3. Throttle position signal Refer to P-502: Throttle Sensor.4. Rack Controls Refer to P-532: Rack Actuation System and P-531: Rack Position Sensor / Calibration.P-305: Engine Misfires Or Runs Rough
Probable root causes:* Fuel System* Valve lash* Faulty Fuel Injector* Fuel Timing* Inlet Air System Problem* Exhaust Problem* Unstable Rack Motion* Cylinder Problem Perform the following tests:1. Fuel System Check fuel quality. Refer to SEBD0717, Diesel Fuel And Your Engine.Check for excessive air in fuel. A 9U6872 Flow Sight Tube installed in the return line is helpful in determining the presence of air in fuel or a plugged fuel return pressure regulating valve. If excessive air is present in the fuel return line, inspect the suction side of the fuel system for leaks. Repair as necessary. If the problem is not found, install a sight tube in the inlet line to the fuel transfer pump. If excessive air is present in the return line, but not in the inlet line, combustion air may be leaking past an injector.Check fuel pressure. The fuel transfer pump outlet pressure at both fuel manifolds should be approximately 415 kPa (60 psi) typical at full load speed. If pressure is low, replace fuel filters. If still low, inspect transfer pump, bypass valve and fuel pressure regulator.2. Valve Lash Check for popping sounds in air inlet. If present, adjust according to the Systems Operation Testing & Adjusting Manual.3. Faulty Fuel Injector Check exhaust manifold port temperatures. Low temperatures at low idle speed may be an indication of no fuel to the cylinder. High temperature can indicate too much fuel.4. Fuel Timing Check according to the Systems Operation Testing & Adjusting manual. Adjust as necessary.5. Inlet Air System Problem Check for loose ducting connections between the turbocharger and inlet manifold. Check for leakage at the inlet manifold. Check for air system problems: plugged air filter, aftercooler restrictions, aftercooler leaks, high inlet air temperature, etc. Maximum inlet restriction measured at the turbocharger inlet is 6.3 kPa (26 in H2O). Refer to Systems Operation Testing and Adjusting for details.6. Exhaust Problem Check for exhaust system restrictions. Maximum