John Deere Error Code ECU 000110.00 — What It Means and How to Fix It

Applies to: 5E Series (5045E-5100E), 5M Series (5075M-5115M), 5R Series (5090R-5125R), 6M Series (6110M-6195M), 6R Series (6110R-6250R), 7R Series (7210R-7310R), 8R Series (8245R-8400R), 9R/9RT/9RX Series, S Series Combines (S760-S790), T Series Combines

STOP — Reduce load immediately, shut down if temperature doesn't drop

Reduce load and idle down. Check coolant level. Inspect and clean the radiator. Do NOT open the radiator cap while hot.

JD ECU 000110.00John DeereManually verified

Engine Coolant Temperature Extremely High

The ECU is detecting that engine coolant temperature has exceeded 115°C / 240°F. This is the most severe level of coolant temperature warning. The ECU will actively derate engine power to protect the engine.

Repair difficulty

DIY — Basic tools

Repair time

15 min

Dealer cost

$200-400

What to check first

  1. 1

    Idle the engine at 800-1000 RPM for 2 minutes — don't shut off immediately, let the water pump circulate coolant

  2. 2

    Check the coolant overflow reservoir — if below MIN, you have a leak or have been losing coolant

  3. 3

    Walk to the front and check the radiator/cooler stack for packed debris, chaff, or dust — clean with a leaf blower if available

Likely causes

  1. 1

    Radiator or cooler stack blocked with debris— Most likely

    DIY

    The most common cause, especially during harvest or bush hogging. Clean the entire cooler stack from the engine side outward.

  2. 2

    Low coolant level from leak at hoses, clamps, or water pump weep hole— Most likely

    DIY

    Check for puddles under the tractor and wet spots around hose connections.

  3. 3

    Failed thermostat stuck closed— Possible

    DIY

    If the upper radiator hose is cool while the gauge shows hot, the thermostat isn't opening. Replacement takes 30-60 minutes.

  4. 4

    Fan clutch failure (viscous coupling worn out)— Possible

    Shop

    The fan should spin faster as temperature rises. If it freewheels at all speeds, the clutch has failed.

  5. 5

    Failed water pump (broken impeller or shaft)— Less common

    Shop

    Less common but serious. Shop recommended for replacement.

  6. 6

    Internally blocked radiator— Less common

    Shop

    Requires removal and professional cleaning or replacement. Use an infrared thermometer to check for cold spots indicating blocked passages.

  7. 7

    Head gasket failure— Less common

    Shop

    Check for milky oil on dipstick, bubbles in coolant reservoir, or sweet smell in exhaust. Major repair.

  8. 8

    Faulty coolant temperature sensor giving false reading— Less common

    DIY

    If everything else checks out, test the sensor with a multimeter. Resistance should change smoothly with temperature.

Parts needed

Tools needed

  • Leaf blower or compressed air
  • Infrared temperature gun ($20-40)
  • 10mm, 12mm, 13mm sockets
  • Ratchet
  • Multimeter (for sensor testing)

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Pro tip

Carry a leaf blower on the tractor during harvest. Blow out the cooler stack every 2-4 hours of operation. Many experienced operators report this completely eliminates overheating codes.

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