John Deere 100.01 – ECU: Engine Oil Pressure Extremely Low

Triggered when the engine oil pressure registered by the sensor drops below the minimum safe operating threshold, indicating either a true mechanical loss of oil pressure or a false reading caused by a faulty sensor or wiring harness.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7220
• 7320
• 8R Series
• 9000 Series
• 648G III
• 444J
• 544J
• 624J
• 210G
• 350GLC
• 7760
• 9660 STS
• 9760 STS

1. 1

   Immediate Shutdown: STOP THE ENGINE IMMEDIATELY to prevent catastrophic internal damage.

2. 2

   Check Oil Level & Quality: Pull the engine dipstick to verify the oil level and ensure the oil is not dangerously low, contaminated with fuel/coolant, or overly degraded.

3. 3

   Visual Inspection: Inspect the engine block, oil pan, and oil filter housing for severe external leaks.

4. 4

   Verify Mechanical Pressure: Connect a mechanical oil pressure gauge to the engine block and crank/run the engine briefly to see if the engine is actually building physical oil pressure.

5. 5

   Inspect Sensor & Wiring: If mechanical pressure is good, inspect the Engine Oil Pressure Sensor and its wiring harness for rubbed wires, a disconnected plug, or a loss of the 5V reference supply from the ECU.

1. 1

   Address Fluid Levels

   If the oil level is low, fill it to the correct specification using John Deere approved oil. If the oil is heavily contaminated, drain the oil, replace the oil filter, and refill.

2. 2

   Sensor/Electrical Repair

   If your mechanical gauge confirms that the engine has healthy oil pressure, disconnect the battery, replace the Engine Oil Pressure Sensor, and reconnect the harness. Splice in a new pigtail connector or repair the wire break if the plug is damaged or the 5V wire is broken.

3. 3

   Mechanical Repair

   If the mechanical gauge confirms that oil pressure is genuinely extremely low, do not run the machine. Drop the oil pan and inspect the oil pump, the oil pickup tube, and the engine main/rod bearings for severe wear, replacing failing components or overhauling the engine as necessary.

4. 4

   Clear Codes

   Turn the key on, verify the sensor is reading correctly on the diagnostic display, start the engine, and ensure the code moves from 'Active' to 'Stored' before clearing it.