34
2. Visually inspect the engine for oil leaks.
3. If the oil level is good, restart the unit and verify the loss of oil pressure. Shut the engine down immediately
if the oil pressure value does not read 5 psi (34 kPa) within five seconds.
4. Check the oil pressure sender. To identify corrective action, refer to the troubleshooting section of the
engine operator’s manual provided with the unit.
LOW COOLANT LEVEL SHUTDOWN
1. Allow the engine to cool! Confirm the unit is sitting level to ensure an accurate reading.
2. Check the coolant level in the radiator. To access the radiator cap, you must open the front hood. Add
coolant until it is 3/4 in. (1.9 cm) below the filler neck. Secure the radiator cap back into its original position.
3. Inspect coolant hoses, engine block and water pump for visible leaks.
4. Check the engine oil to verify no coolant has mixed with it (oil will appear milky if coolant is present).
Consult the engine operator’s manual for additional information.
HIGH COOLANT TEMPERATURE SHUTDOWN
1. Check the coolant level in the overflow jug.
2. Restart the engine and read the coolant temperature to verify High Coolant Temperature Shutdown.
Stop the engine immediately if the coolant temperature is 230°F (110°C) or more.
3. Allow the engine to cool. Add coolant to the overflow jug if it is low and then check the level of coolant
in the radiator. To access the radiator cap, you must open the front hood. Add coolant until it is 3/4 in.
(1.9 cm) below the filler neck. Secure the radiator cap back into its original position.
4. Check the radiator shroud and ducting for blockage and remove any foreign matter.
5. Inspect coolant hoses, engine block and water pump for visible leaks.
6. Check the tension of the serpentine drive belt for the water pump.
7. If no other problems are found, remove the load on the generator and restart the engine. Check the
coolant temperature and shut the engine down immediately if it starts to overheat. Consult the engine
operator’s manual for additional information on engine overheating.
OVERCRANK SHUTDOWN
1. Check the fuel level in the tank.
2. Check for proper operation of the fuel pump.
3. Check the air filter for blockage.
4. If the engine will not start, consult the engine operator’s manual for additional information on trouble-
shooting starting problems.
OVERSPEED OR UNDERSPEED SHUTDOWN
1. Disconnect all loads and restart the generator. Read the frequency (Hz) on the LCD display. With no
loads on the generator, the frequency should read 60.0 Hz.
2. If the frequency is above or below 60.0 Hz, the engine speed will have to be adjusted. Refer to the engine
operator’s manual for throttle adjustments on mechanical governed units and refer to the electronic
governor manual for electronically controlled units. MMG55FHD units will need to contact John Deere
with speed related issues since the engine is governed by the John Deere Electronic Engine Control
Unit (ECU).
