John Deere 27.04 – Engine Control Unit (ECU): Engine EGR Valve Position Signal Too Low (ECU) / EGR Valve Position Signal Out of Range Low

This code triggers when the position signal voltage from the Exhaust Gas Recirculation (EGR) valve falls below the lower acceptable limit. This typically indicates a short to ground within the valve's electrical circuit. The short can be caused by exposed wiring, corroded connectors, or an internal failure of the position sensor integrated into the EGR valve itself. When this code is active, the engine will typically derate (limit power) and active exhaust filter cleaning will be unavailable.

• 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
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8345RT
• 9470RT
• 9520RT
• 9570RT
• 7760
• CP690
• S-Series Combines

1. 1

   Cycle power by turning off the engine and cycling the key switch to see if the code clears or remains active.

2. 2

   Inspect the wiring harness leading to the EGR valve for chafing, exposed wires, or melting that could cause a short to ground.

3. 3

   Disconnect the EGR valve and inspect the pins for corrosion, moisture, or damage.

4. 4

   Perform a connector voltage check on the harness side with the EGR valve disconnected. If the short-to-ground disappears when unplugged, the internal sensor of the EGR valve has failed. If the short remains, the wiring harness between the ECU and the EGR valve is compromised.

5. 5

   Use John Deere Service ADVISOR (or a compatible diagnostic tool) to command the EGR actuator to move and monitor the 'EGR Position (EGRP)' versus the 'EGR Valve CTL (EGRC)'. If the valve does not move or the position signal remains bottomed out, the valve is mechanically bound or electrically dead.

1. 1

   Disconnect battery

   Turn off the machine, remove the key, and disconnect the battery ground cable.

2. 2

   Locate EGR valve

   Locate the EGR valve assembly on the engine's intake/exhaust manifold.

3. 3

   Disconnect electrical connector

   Disconnect the electrical connector from the EGR valve.

4. 4

   Remove mounting bolts

   Remove the mounting bolts securing the EGR valve to the manifold and EGR cooler.

5. 5

   Remove EGR valve

   Carefully remove the EGR valve. Note: Take this opportunity to inspect the EGR cooler for excessive unburnt fuel (soot) deposits, which is a common issue in light-loading situations and can cause the valve to bind.

6. 6

   Clean mating surfaces

   Clean the mating surfaces on the manifold thoroughly, ensuring no old gasket material remains.

7. 7

   Install new EGR valve

   Install the new EGR valve using a new OEM gasket.

8. 8

   Torque mounting bolts

   Torque the mounting bolts to the specifications outlined in your specific engine's technical manual.

9. 9

   Reconnect electrical connector and battery

   Reconnect the electrical connector and the battery ground.

10. 10

    Clear fault code and verify

    Connect a diagnostic tool to clear the ECU 000027.04 fault code, start the engine, and verify that the code does not return and engine power is restored.