Case IH 3795 (F-102-17) – Engine Control Unit (ECU) / Engine Control Module (ECM): Intake Manifold Boost Pressure Value Illogical When Compared To Other Pressures In System

A boost pressure plausibility check has detected that the actual turbocharger boost pressure is lower than expected for the current engine load and speed. This is an underboost condition where the engine is not receiving the commanded amount of pressurized air.

• VESTRUM CVX
• Steiger
• Magnum
• Puma
• Maxxum
• Farmall
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Excavators
• CX210
• CX240

1. 1

   Inspect the entire air intake system for leaks, checking hose clamps, intercooler (charge air cooler) connections, and piping for cracks or blow-outs

2. 2

   Check the engine air filter for severe restrictions or blockages that could starve the turbocharger of air

3. 3

   Inspect the turbocharger wastegate or Electronic Variable Geometric Turbocharger (EVGT/VGT) actuator for a sticking vane, disconnected linkage, or stuck-open wastegate

4. 4

   Check the boost pressure sensor (MAP sensor) and its wiring harness for damaged wires, corrosion in the connector, or a shorted signal

5. 5

   Check for exhaust leaks upstream of the turbocharger that could reduce the exhaust drive pressure required to spool the turbine

1. 1

   Visual Inspection & Tightening

   Start by visually inspecting the air intake and charge air cooling system. Tighten any loose hose clamps and replace any split or damaged intercooler hoses.

2. 2

   Air Filter Replacement

   If the air filter is restricted or heavily soiled, replace both the primary and secondary air filters.

3. 3

   Turbocharger Actuator Service

   If the machine is equipped with a VGT, test the actuator's movement. If it is physically stuck, attempt to free the linkage or replace the VGT actuator. Note: On some models (like Puma and Magnum), the electronic VGT actuator may need to be recalibrated using a dealer service tool if replaced.

4. 4

   Sensor Replacement

   If the intake system is completely sealed and the turbocharger is functioning correctly, the boost pressure sensor is likely faulty. Disconnect the sensor harness, remove the sensor from the intake manifold, and install a new OEM boost pressure sensor.

5. 5

   Clear and Retest

   Use a diagnostic service tool to clear the fault code. Run the engine and perform a test drive under load to ensure the target boost pressure is met and the code does not return.