Case IH 2659 – Engine Control Unit (ECU / EDC): EGR System Failure or Mismatch

Indicates a failure or mismatch in the Exhaust Gas Recirculation (EGR) system. Specifically, it points to an issue with the EGR Delta Pressure Sensor (B5103) or an EGR mass flow/temperature plausibility error.

• Steiger T4B
• Steiger
• Magnum
• Puma
• Optum
• Maxxum
• Axial-Flow combines

1. 1

   Read the Sub-Code (FMI) using the CNH Electronic Service Tool (EST) to determine if the fault is electrical (FMI 3, 4) or mechanical/flow-related (FMI 14, 15, 17)

2. 2

   For FMI 3 or 4 (Electrical): Inspect the wiring harness leading to the EGR Delta Pressure Sensor (B5103) for chafed wires, corrosion, or an open circuit, and verify the 5V reference voltage from the ECU

3. 3

   For FMI 14, 15, or 17 (Mechanical): Check the EGR valve/actuator to see if it is physically stuck open or closed due to soot buildup

4. 4

   Inspect the EGR gas piping and the EGR cooler for severe carbon/soot blockages or cracks that would restrict exhaust gas flow

1. 1

   For Electrical Faults

   Disconnect the EGR Delta Pressure Sensor. Use a multimeter to test continuity between the sensor connector and the Engine ECU pins. Repair any broken wires or shorts to ground. If the wiring is intact and the 5V supply is present, the sensor itself has failed internally and must be replaced.

2. 2

   For Flow/Mechanical Faults

   Remove the EGR valve assembly. Inspect the valve shaft; if it is broken, the entire valve assembly must be replaced. If it is heavily carboned but intact, clean the valve and actuator thoroughly using an approved EGR cleaning solvent.

3. 3

   Clear Blockages

   If the valve is functioning properly but code 2659 17 (no flow) is active, remove the EGR cooler and piping. Clean out soot blockages. If the cooler is completely plugged and cannot be cleaned, replace the EGR cooler.

4. 4

   Reassembly and Testing

   Reinstall all components. Connect the diagnostic tool, clear the inactive fault codes, and run the engine under load to verify that the EGR system returns to Closed-Loop operation without throwing the code.