John Deere 111.17 – ECU: Engine Coolant Level Switch Shows Low Coolant Level

The engine control system has detected that the coolant level in the surge tank or radiator has dropped below the service switch threshold.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8360R
• 9410R
• 9470RT
• 9520RT
• 9570RT
• 7760 Cotton Picker
• 130G
• 260E
• 370E
• 460E
• 450K
• 1050K

1. 1

   Physically verify the coolant level in the radiator or surge tank. Do not rely solely on the sensor.

2. 2

   Check the engine block, radiator, hoses, and water pump for any signs of active coolant leakage.

3. 3

   Determine if the DTC periodically goes away (e.g., when driving on rough terrain or inclines), which could indicate the fluid is just barely at the threshold level.

4. 4

   Inspect the wiring harness and connector going to the coolant level switch for corrosion, chafing, or a loose connection.

1. 1

   Top Off Coolant

   If the coolant is genuinely low, add the manufacturer-approved coolant until it reaches the 'MAX' or 'FULL' line on the reservoir.

2. 2

   Cycle Power

   Turn the ignition key off and back on to see if the code clears after the fluid level is restored.

3. 3

   Address Leaks

   If the system was low, pressure-test the cooling system to find and repair the leak.

4. 4

   Test/Replace the Sensor

   If the coolant level is full but the ECU still registers code 000111.17, the coolant level switch has likely failed internally or is fouled by coolant additives. Drain the coolant below the sensor port, remove the old sensor, install the new sensor, and refill the system.