John Deere 157.03 – Engine Control Unit (ECU): The Fuel Rail Pressure Sensor Signal Voltage Is Too High

The input voltage from the fuel rail pressure sensor exceeds the sensor's maximum high-voltage specification, indicating a pressure greater than what is physically possible in the fuel line. This is typically caused by an open in the ground circuit, a short in the wiring harness to a 12-volt or high-voltage source, or a complete failure of the fuel rail pressure sensor itself.

• 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
• 6110R through 6215R
• 8R Series
• 9470RT
• 9520RT
• 9570RT
• 135D
• 450DLC
• 333E

1. 1

   Check the fuel tank level to rule out extreme fuel starvation, which can trigger erratic pressure readings

2. 2

   Run the engine to operating temperature to determine if the code is intermittent or persistent

3. 3

   Inspect the wiring harness leading to the fuel rail pressure sensor for chafed wires, melted insulation, or pinched lines

4. 4

   Disconnect the sensor and inspect the connector pins for corrosion, moisture, or poor terminal tension

5. 5

   Test the ground circuit for continuity to ensure there is no open circuit

6. 6

   Test the signal wire with a multimeter to verify if it is shorted to a 12V power source

1. 1

   Power Down

   Turn off the machine and disconnect the battery to ensure safety while working on the ECU wiring harness.

2. 2

   Repair Wiring

   If your multimeter tests reveal an open ground or a short to power in the harness, repair or replace the damaged section of the wiring harness.

3. 3

   Replace the Sensor

   If the wiring harness and connectors test perfectly fine, the sensor itself has failed internally. Relieve fuel system pressure safely, remove the faulty fuel rail pressure sensor from the common rail, and install the new OEM sensor, torquing it to the manufacturer's specification.

4. 4

   Reassemble and Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic tool to clear the 000157.03 / SPN 157 FMI 3 fault code.

5. 5

   Test Run

   Start the engine and verify that full power is restored and the code does not return.