New Holland 124 – ENGINE controller (ECM): Boost Pressure Level Exceeds Warning Limit

The engine's electronic control module (ECM) has detected that the turbocharger boost pressure is significantly higher than the expected level for the current engine speed and load. This overboost condition can lead to reduced engine performance, potential engine damage if left unaddressed, and the activation of the check engine light.

• T6
• T7
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190
• T6000 Series
• T6.120
• T6.140
• T6.150
• T6.155
• T6.160
• T6.180

1. 1

   Visually inspect the turbocharger and air intake system for disconnected, cracked, or blocked hoses and loose clamps, paying close attention to the vacuum lines connected to the wastegate actuator.

2. 2

   Check for other active or stored fault codes (such as 122, 123, or 419) that could indicate a boost pressure sensor voltage or data issue.

3. 3

   Manually verify that the wastegate actuator rod is not seized or disconnected and can move freely, as a stuck-closed wastegate is a common cause of overboost.

4. 4

   Inspect the boost pressure sensor (MAP sensor) for soot or carbon buildup obstructing the sensing port, and check the electrical connector and wiring for damage, corrosion, or loose connections.

1. 1

   Clean the boost pressure sensor

   Locate and remove the boost pressure sensor. Carefully clean the sensor element and port using a suitable electronic parts cleaner. Reinstall the sensor, clear the fault codes, and operate the machine to see if the fault returns.

2. 2

   Test the wastegate control solenoid

   Using a diagnostic tool, actuate the wastegate control solenoid to test its function. Alternatively, test the solenoid's electrical circuit for proper voltage and resistance according to the service manual.

3. 3

   Test the boost pressure sensor

   With the sensor connected, back-probe the signal wire using a multimeter. With the key on and engine off, the signal voltage should correspond to atmospheric pressure. If possible and safe, monitor the sensor's reading with a diagnostic tool while the engine is running to ensure it provides a plausible signal that changes with engine load.

4. 4

   Inspect the turbocharger

   If the sensor and wastegate control system are functioning correctly, check the turbocharger for internal issues, such as a sticking variable geometry turbine (VGT) mechanism or a faulty internal wastegate. This may require removal and inspection by a qualified technician.

5. 5

   Check the ECM

   In rare cases, the issue could be with the Engine Control Module (ECM). This should only be considered after all other possibilities have been exhausted.