John Deere 001075.05 – ECU: Electric Lift Pump Circuit Fault

The Engine Control Unit (ECU) has detected that the current in the electric fuel lift pump circuit is below the normal operating range or the circuit is open (high resistance). This indicates the lift pump is not receiving proper electrical power due to a wiring break, failed component, or poor connection, which can lead to a loss of fuel pressure, hard starting, reduced engine power, or engine shutdown.

• 9230
• 9330
• 9430
• 9530
• 9630
• 7630
• 7730
• 7830
• 7930
• 5000 Series
• 6000 Series
• 7000 Series
• 9560 STS
• 9660 STS
• 9760 STS
• 9860 STS
• 4.5L (4045) Engine
• 6.8L (6068) Engine

1. 1

   Visually inspect the wiring harness and connectors leading to the electric lift pump for damage, corrosion, chafing, or loose connections.

2. 2

   Check for power at the pump: With the key in the 'ON' position (engine off), verify voltage at the pump's electrical connector is within one volt of battery voltage. If no voltage is present, the issue is likely upstream in the wiring, fuse, or relay.

3. 3

   Check the ground circuit: With the pump plugged in, test the ground wire using a test light connected to a known good positive source (it should not light up).

4. 4

   Check for an open circuit: Disconnect the fuel lift pump and the ECU connector, then measure resistance of the wiring between them. An 'OL' or infinite reading indicates a broken wire.

5. 5

   Check pump resistance: Measure the internal resistance of the fuel pump across its terminals. Infinite resistance indicates an internal open circuit and a failed pump.

1. 1

   Ensure safety and locate pump

   Park the machine on a level surface, turn it off, and disconnect the battery. Locate the electric lift pump on the frame or integrated into the base of the primary fuel filter.

2. 2

   Repair wiring and connectors

   If diagnostic checks revealed a damaged wire or corroded connector, repair or replace the faulty section of the harness. Ensure all connections are clean and secure.

3. 3

   Replace the electric lift pump

   If diagnostics confirm the pump has an internal open circuit, place a container under the pump, disconnect the electrical connector and fuel lines (cap them immediately to prevent contamination), unbolt the assembly, and install the new pump using new gaskets or seals.

4. 4

   Prime the fuel system

   Turn the ignition key to the 'ON' position (without cranking) to allow the new pump to prime the system. Cycle the key a few times if necessary.

5. 5

   Final check

   Start the engine and check for any fuel leaks around the pump and its connections. Clear the fault codes and verify that code 001075.05 does not reappear.