John Deere 3514.03 – Engine Control Unit (ECU): Sensor Supply #6 Voltage Out of Range High

The 5-volt reference circuit (Sensor Supply #6) is reading a voltage that exceeds the upper limit. This is typically caused by a short to a 12V power source (battery voltage) or an open ground within the circuit.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6M series
• 6R series
• 7R series
• 8R series
• 8RT series
• 9R series
• 6150R
• 7230R
• 8320R
• 9470RT
• 9520RT
• 9570RT
• S650
• S660
• S670
• S760
• 8000 series forage harvesters
• 8200 series forage harvesters
• 250D
• 300D
• 130G
• 210G
• 544K
• 744L
• 1110E
• 1210E
• R4030
• R4038
• R4044
• R4045

1. 1

   Verify the Code: Use a diagnostic scan tool to confirm ECU 003514.03 is active.

2. 2

   Sensor Isolation Test: Disconnect the sensors on this circuit (EGR Valve Position Sensor, Exhaust Manifold Pressure Sensor, and Coolant Pressure Sensor) one at a time. Check the active fault codes or monitor the 5V supply voltage with a multimeter after unplugging each sensor. If the voltage returns to a normal 5V (or the code changes from 3514.03 'High' to 3514.04 'Low/Open'), the sensor you just disconnected is internally shorted and needs to be replaced.

3. 3

   Harness Inspection: If disconnecting the sensors does not resolve the high voltage reading, inspect the engine wiring harness. Look for chafing, melted wires, or rubbing against the engine block, EGR cooler, or exhaust manifold that could cause the 5V wire to short against a 12V power wire.

4. 4

   Connector Check: Inspect the ECU pins and sensor connectors for corrosion, moisture, or bent pins.

1. 1

   Power Down

   Turn off the ignition key and disconnect the negative battery cable to prevent electrical spikes during repair.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a short to 12V in the wiring harness, splice and repair the damaged section of the harness using proper heat-shrink connectors, or replace the affected harness section.

3. 3

   Replace Faulty Sensor

   If a sensor was found to be internally shorted, remove the retaining bolts or unthread the sensor from its port. Install the new OEM sensor and torque to the manufacturer's specifications.

4. 4

   Reassemble

   Reconnect all sensor pigtails and the battery cable.

5. 5

   Clear Codes

   Turn the key to the ON position and use a diagnostic tool to clear the ECU 003514.03 fault code.

6. 6

   Test Run

   Start the engine and monitor the Sensor Supply #6 voltage to ensure it remains at a stable 5 volts. Verify that no check engine lights return.