BMW DTC P0404 – EGR ‘A’ Control Circuit Range/Performance
DTC P0404 meaning on BMW
DTC P0404 on a BMW indicates an issue with the Exhaust Gas Recirculation (EGR) ‘A’ Control Circuit. This fault code is triggered when the Engine Control Module (ECM) detects that the EGR system is not operating within the expected range or performance parameters.
BMW DTC P0404 symptoms
Symptoms of a DTC P0404 on a BMW may include:
- Check Engine Light illuminated
- Decreased fuel efficiency
- Engine hesitation or rough idling
- Increased emissions
BMW DTC P0404 causes
Common causes of a DTC P0404 on a BMW include:
- Defective EGR valve
- Blocked EGR passages
- Faulty EGR position sensor
- Wiring or connector issues in the EGR circuit
BMW DTC P0404 seriousness
While a DTC P0404 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions if left unresolved. It is important to address this fault code to ensure optimal engine performance and emissions compliance.
How to diagnose DTC P0404 on BMW
To diagnose a DTC P0404 on a BMW, a mechanic may perform the following steps:
- Use a diagnostic scan tool to retrieve the fault code and freeze frame data
- Inspect the EGR valve and related components for any visible damage or blockages
- Test the EGR valve position sensor for proper operation
- Check the wiring and connectors in the EGR circuit for continuity and proper connections
How to fix DTC P0404 on BMW
To fix a DTC P0404 on a BMW, the following steps may be taken:
- Clean or replace the EGR valve if it is found to be faulty or blocked
- Repair any damaged wiring or connectors in the EGR circuit
- Replace the EGR position sensor if it is determined to be defective
- Clear the fault code and perform a test drive to ensure the issue has been resolved
How to erase DTC P0404 on BMW
To erase a DTC P0404 on a BMW, the fault code can be cleared using a diagnostic scan tool. After the repair has been completed, the mechanic can use the scan tool to clear the code and reset the Check Engine Light. It is important to verify that the issue has been resolved before clearing the fault code.
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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