Case IH 19625 – Engine Control Module (ECM / ECU): Over Boost Detection

The engine control system has detected that the intake manifold boost pressure has exceeded the maximum safe operating limit. This typically means the turbocharger is producing too much boost pressure, or the boost pressure sensor is providing an erroneously high reading to the computer.

• Tier 4b
• Farmall 65C
• Farmall 75C
• Farmall 100C
• Farmall 110C
• Farmall 100N
• Farmall 110V
• 580N
• 580SN
• 590SN
• 650M
• 586H
• 588H
• SR210
• SR240
• SV280
• TR270
• TR310
• TV370
• C227
• L228

1. 1

   Sensor Plausibility Check: Use a diagnostic scan tool to read the Boost Pressure Sensor (MAP sensor) with the engine off. The boost pressure should match the ambient atmospheric pressure. If the sensor reads high with the engine off, the sensor is faulty.

2. 2

   Wiring Inspection: Inspect the wiring harness and connector to the boost pressure sensor for chafing, corrosion, short circuits to a voltage source, or open circuits.

3. 3

   Wastegate Actuator Check: Inspect the turbocharger wastegate and its linkage. Ensure the wastegate is not physically stuck or blocked in the closed position, which would prevent it from bleeding off excess exhaust gas and cause a genuine overboost condition.

4. 4

   Boost Pressure Modulator Valve: Test the boost pressure modulator valve (which electrically regulates the pressure sent to the wastegate actuator). Ensure it is functioning and not clogged.

5. 5

   Hose Inspection: Check the vacuum/pressure lines running to the wastegate actuator for splits, cracks, or blockages.

1. 1

   Clear and Retest

   Clear the fault code and run the machine under load to see if the overboost condition returns.

2. 2

   Replace Sensor

   If the boost pressure sensor failed the key-on/engine-off plausibility check, disconnect the battery, remove the old sensor from the intake manifold, install the new sensor, and reconnect the harness.

3. 3

   Free the Wastegate

   If the wastegate linkage is seized, apply penetrating oil and manually work the linkage until it moves freely. If the internal wastegate flap is damaged or permanently seized, the turbocharger assembly may need to be replaced or rebuilt.

4. 4

   Replace Modulator Valve/Lines

   If the lines to the wastegate are cracked, replace them. If the boost pressure modulator valve fails electrical testing, replace the valve.

5. 5

   Final Verification

   Clear the codes and operate the machine at full load to ensure boost pressure remains within the specified physical range.