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.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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