120408 – BMW DTC

BMW DTC 120408 – Charging pressure control: Switch-off as consequential reaction / Charging pressure control, deactivation: pressure build-up blocked

DTC 120408 meaning on BMW

DTC 120408 refers to a fault in the charging pressure control system of BMW vehicles. This code indicates that the system has detected a switch-off condition due to a blocked pressure build-up. The charging pressure control is crucial for maintaining optimal performance and efficiency in turbocharged engines.

BMW DTC 120408 symptoms

Common symptoms associated with DTC 120408 may include:

  • Reduced engine power or performance
  • Increased fuel consumption
  • Check Engine Light illuminated
  • Turbocharger not functioning properly
  • Unusual engine noises

BMW DTC 120408 causes

The causes of DTC 120408 can vary, but typical reasons include:

  • Blocked or restricted intake or exhaust pathways
  • Faulty pressure sensors or switches
  • Issues with the turbocharger itself
  • Vacuum leaks in the intake system
  • Faulty wastegate or actuator

BMW DTC 120408 seriousness

DTC 120408 is considered a serious issue as it can lead to:

  • Significant loss of engine performance
  • Potential engine damage if not addressed
  • Increased emissions
  • Long-term reliability concerns

How to diagnose DTC 120408 on BMW

To diagnose DTC 120408, follow these steps:

  • Use an OBD-II scanner to confirm the DTC and check for any related codes.
  • Inspect the intake and exhaust systems for blockages or restrictions.
  • Check the operation of the turbocharger and wastegate.
  • Test the pressure sensors and switches for proper functionality.
  • Look for vacuum leaks in the intake system.

How to fix DTC 120408 on BMW step-by-step instructions

To fix DTC 120408, follow these steps:

  • Clear the DTC using an OBD-II scanner.
  • Inspect and clean any blocked intake or exhaust components.
  • Replace faulty pressure sensors or switches as needed.
  • Repair or replace the turbocharger or wastegate if they are malfunctioning.
  • Seal any vacuum leaks in the intake system.
  • Recheck the system for proper operation and ensure no new codes appear.

How to erase DTC 120408 on BMW

To erase DTC 120408, perform the following:

  • Connect an OBD-II scanner to the vehicle’s diagnostic port.
  • Access the diagnostic menu and select the option to clear or erase codes.
  • Confirm the action and wait for the scanner to complete the process.
  • Disconnect the scanner and start the engine to verify that the code does not reappear.