Case IH F-157-11 - ECU – Engine Control Unit (ECU): Fuel rail pressure sensor voltage is higher than expected.

The control module is receiving a voltage signal from the fuel rail pressure sensor that exceeds the maximum calibrated threshold. This condition is typically caused by a short circuit to a higher voltage source (like battery voltage), an open circuit on the sensor's ground/return line, or an internal failure of the sensor itself.

• MAGNUM AFS Connect
• 240 Series Axial-Flow Combines
• Magnum Series (245, 275, 305, 335, MX215-MX305)
• Steiger Series (280, 330, 335, STX280, STX330)
• Puma Series (140-220)
• Farmall Series (90C-120U)

1. 1

   Verify that the machine battery has not been connected to an external power supply or jump-started improperly. If an external power supply is connected, disconnect it, clear the codes, and test the system for normal operation.

2. 2

   Turn the ignition switch to the OFF position and disconnect the fuel rail pressure sensor connector and the corresponding ECU connector.

3. 3

   Check the rail pressure sensor signal circuit for an open circuit condition.

4. 4

   Test the wiring harness for a short to battery voltage between the sensor and the ECU.

1. 1

   Depressurize fuel system

   Ensure the machine is turned off, the key is removed, and the fuel system is depressurized.

2. 2

   Locate sensor

   Locate the fuel rail pressure sensor on the high-pressure fuel rail.

3. 3

   Disconnect harness

   Disconnect the electrical harness from the sensor.

4. 4

   Remove sensor

   Remove the faulty sensor from the fuel rail. Important Note: Fuel rail pressure sensors are generally designed as a 'one-time torque' component. Removal and re-installation of an old sensor can cause leaks. Always install a new sensor if the old one is removed.

5. 5

   Install new sensor

   Thread the new sensor into the fuel rail and torque it to the exact OEM specification for your specific engine model.

6. 6

   Reconnect harness

   Reconnect the electrical harness.

7. 7

   Test system

   Prime the fuel system, start the engine, check for leaks around the rail, and verify that the fault code has cleared.