BMW DTC P1678 – ACC (Adaptive Cruise Control) no Response to ACC Cut-Off
DTC P1678 meaning on BMW
The Diagnostic Trouble Code (DTC) P1678 for BMW indicates that there is no response from the Adaptive Cruise Control (ACC) system when the ACC is cut off. This means that the ACC system is not functioning properly and is not able to adjust the vehicle’s speed accordingly.
BMW DTC P1678 symptoms
Symptoms of DTC P1678 on a BMW may include:
- Adaptive Cruise Control not engaging or disengaging properly
- Inability to set or maintain a desired following distance
- ACC warning light illuminated on the dashboard
BMW DTC P1678 causes
Common causes of DTC P1678 on a BMW include:
- Malfunctioning ACC sensor
- Electrical issues in the ACC system
- Software glitches in the ACC control module
BMW DTC P1678 seriousness
The seriousness of DTC P1678 on a BMW lies in the potential safety implications. A malfunctioning ACC system can lead to unexpected changes in vehicle speed, which may compromise driving safety, especially in traffic or on highways.
How to diagnose DTC P1678 on BMW
To diagnose DTC P1678 on a BMW, you can:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the ACC system components for any visible damage or loose connections
- Perform a system reset to see if the issue persists
How to fix DTC P1678 on BMW
To fix DTC P1678 on a BMW, you may need to:
- Replace the faulty ACC sensor or any damaged components
- Check and repair any electrical issues in the ACC system
- Update the software in the ACC control module
How to erase DTC P1678 on BMW
To erase DTC P1678 on a BMW, you can:
- Use a diagnostic scanner to clear the fault codes
- After fixing the underlying issue, perform a system reset to ensure the fault 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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