Case IH F-157-21 - ECU – Engine Control Unit (ECU) / EEM4 Motor Controller: Rail pressure sensor value is below minimum offset

The raw rail pressure value has drifted low and is below the minimum displacement threshold, indicating insufficient fuel rail pressure.

• MAGNUM AFS Connect
• 240 Series Axial-Flow Combines
• Puma series
• Puma 210
• CVX series
• CVX 140
• CVX 150
• CVX 160
• CVX 175
• CVX 195
• Farmall series
• Farmall 90C
• Farmall 95A
• Farmall 100C
• Farmall 110U
• Farmall 120C
• Maxxum series
• Maxxum 110
• Maxxum 115
• Maxxum 125
• Maxxum 140
• Magnum series
• Steiger series
• JX90
• MX/TG series

1. 1

   Check the wiring harness and electrical connections to the fuel rail pressure sensor for shorts, opens, or corrosion.

2. 2

   Verify the proper functioning of the rail pressure sensor itself.

3. 3

   Inspect the common rail system for any physical fuel leaks, especially during load conditions or at idle.

4. 4

   Check the fuel supply system for reasons causing insufficient rail pressure, such as blocked fuel filters or a failing fuel injection pump.

1. 1

   Relieve fuel system pressure

   Relieve the fuel system pressure and safely remove the defective fuel rail pressure sensor.

2. 2

   Install replacement sensor

   Install the replacement fuel rail pressure sensor.

3. 3

   Connect diagnostic tool

   Connect the diagnostic tool to the machine's ECU.

4. 4

   Reset learning values

   Reset the learning values in the EEPROM / initiate the "New learning" procedure so the ECU can calibrate to the new sensor's baseline offset.