BMW DTC P0674 – Cylinder 4 Glow Plug Circuit/Open
DTC P0674 meaning on BMW
The Diagnostic Trouble Code (DTC) P0674 for BMW indicates a fault in the Cylinder 4 Glow Plug Circuit, specifically an open circuit. Glow plugs are used in diesel engines to help with cold starts by heating the air in the combustion chamber. When the Engine Control Module (ECM) detects an open circuit in the glow plug circuit of cylinder 4, it triggers the P0674 fault code.
BMW DTC P0674 symptoms
Symptoms of the DTC P0674 in a BMW may include:
- Hard starting, especially in cold weather
- Rough idling or misfiring
- Reduced engine performance
- Check Engine Light (CEL) illuminated on the dashboard
BMW DTC P0674 causes
Common causes of the DTC P0674 in a BMW include:
- Defective glow plug in cylinder 4
- Wiring issues such as a broken wire or poor connection
- Faulty glow plug control module
- ECM software issues
BMW DTC P0674 seriousness
While the DTC P0674 may not cause immediate drivability issues, it can lead to starting problems and reduced engine performance, especially in cold conditions. Ignoring this fault can potentially lead to further damage to the engine over time.
How to diagnose DTC P0674 on BMW
To diagnose the DTC P0674 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault code and freeze frame data
- Inspect the glow plug in cylinder 4 for continuity and proper operation
- Check the wiring harness for any visible damage or loose connections
- Test the glow plug control module for proper function
- Verify the ECM software is up to date
How to fix DTC P0674 on BMW
To fix the DTC P0674 on a BMW, you can consider the following actions:
- Replace the faulty glow plug in cylinder 4
- Repair or replace any damaged wiring in the glow plug circuit
- Replace the glow plug control module if necessary
- Update the ECM software to the latest version
How to erase DTC P0674 on BMW
To erase the DTC P0674 on a BMW after fixing the underlying issue, you can use a diagnostic scanner to clear the fault code. Simply access the ECM through the scanner, navigate to the DTC section, and select the option to clear the code. Once cleared, the Check Engine Light should turn off, indicating the fault code has been successfully erased.
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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