Technical Service Bulletin LI09.40-N-079144_4 — 2021 FREIGHTLINER SPRINTER 1500

Check engine light with reduced power with fault codes P300A6D, P300974, P300DFB, or P300DE8 Complaint: The check engine light is activated, accompanied by one or more of the following fault codes related to the Boost Pressure Positioner: • P300A6D The boost pressure is too low. Charge Air Cooler. • P300974 Component 'Boost pressure positioner' has a malfunction. The boost pressure is too low. • P300DFB Component 'Boost pressure positioner' has a malfunction. • P300DE8 Boost pressure control A has a malfunction after the cold start. Cause: The potential causes for these fault codes are: A. Leak or Blockage in the Intake or Charge Air System: This can prevent the proper flow of air, affecting the boost pressure. B. Insufficient Source Vacuum, Vacuum Leak, or Sticking/Weak Vacuum Component: These issues can prevent the boost pressure positioner from functioning correctly. C. Internal Malfunction of the Boost Pressure Positioner: The component itself may be faulty. D. Internal Defect with the Variable Turbine Geometry (VTG) System inside the Turbocharger: Issues within the turbo-charger can affect boost pressure control.