Case IH 3425 – Engine Control Unit (ECU) A-095: Under boost failure

The system monitors boost pressure using the intake boost pressure sensor (B-013). This fault is logged when the control unit determines that the actual turbocharger boost pressure is lower than the expected target value based on current engine speed and ambient atmospheric pressure.

• Steiger T4B
• Puma series (125, 150, 165, 175, 185)
• Maxxum series (110-145)
• Magnum series (250, 280, 310, 340, 380)
• Optum CVXDrive series
• 240 Series Axial-Flow Combines (7240, 8240, 9240)

1. 1

   Verify that the machine is not being operated in extreme environmental ambient pressures (e.g., extreme high altitudes) which can naturally cause under-boost conditions.

2. 2

   Check for a restricted or heavily soiled engine air filter.

3. 3

   Inspect all charge air piping, the intercooler, and boost hoses for cracks, loose clamps, or disconnected joints.

4. 4

   Visually inspect the turbocharger wastegate linkage (if equipped) to verify it is not damaged, disconnected, or seized.

5. 5

   Visually inspect the Electronic Variable Geometric Turbocharger (eVGT) actuator mechanism (if equipped) to verify the linkage is properly attached and is not restricted, sticking, or blocked.

6. 6

   Check the wiring harness and connectors leading to the intake boost pressure sensor (B-013) for shorts, corrosion, or loose pins.

1. 1

   Verify the Fault

   Connect the Case IH Electronic Service Tool (EST) to check the status of the fault. Determine if DTC 1438 is currently active or inactive.

2. 2

   Resolve Air/Leak Issues

   Replace the air filter if restricted. Re-secure or replace any leaking charge air hoses or clamps.

3. 3

   Free or Replace Turbo Linkage

   If the eVGT actuator or wastegate linkage is physically jammed, attempt to free the mechanism. If the actuator has failed internally or the linkage is broken, the actuator or turbocharger assembly must be replaced.

4. 4

   Replace the Boost Pressure Sensor

   If no mechanical leaks or turbocharger binding are found, the intake boost pressure sensor (B-013) is likely providing an inaccurate reading and should be replaced.

5. 5

   Reset the Inducement System

   If this fault is detected 3 times within a 40-hour operating window, the engine inducement system will lock, resulting in severe engine power loss/derate. After repairing the physical issue, you must use the dealer Electronic Service Tool (EST) and navigate to the "Engine Restart Counter Reset" screen to clear the DTC FBBF (3436) inducement lock.