BMW DTC P1404 – Cold Start EGR ‘B’ Control Stuck Closed
DTC P1404 meaning on BMW
DTC P1404 on a BMW indicates an issue with the Cold Start Exhaust Gas Recirculation (EGR) ‘B’ control valve being stuck closed. The EGR system is responsible for recirculating a portion of the exhaust gases back into the intake manifold to reduce emissions and control combustion temperatures.
BMW DTC P1404 symptoms
Symptoms of a Cold Start EGR ‘B’ Control Stuck Closed DTC may include rough idling, engine hesitation, decreased fuel efficiency, and potentially an illuminated Check Engine Light on the dashboard.
BMW DTC P1404 causes
The most common causes of the DTC P1404 on a BMW are a faulty EGR valve, carbon buildup in the EGR system, electrical issues with the EGR control circuit, or a malfunctioning EGR temperature sensor.
BMW DTC P1404 seriousness
While the DTC P1404 may not cause immediate drivability issues, it can lead to increased emissions and reduced engine performance over time if left unresolved. It is recommended to address this issue promptly to prevent further damage to the engine and emissions system.
How to diagnose DTC P1404 on BMW
To diagnose the DTC P1404 on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and perform a visual inspection of the EGR system components. They may also test the EGR valve, check for vacuum leaks, and inspect the wiring and connectors related to the EGR system.
How to fix DTC P1404 on BMW
Fixing the DTC P1404 on a BMW may involve cleaning or replacing the EGR valve, clearing any carbon buildup in the EGR system, repairing any damaged wiring or connectors, or replacing the EGR temperature sensor if faulty. It is important to follow the manufacturer’s recommended repair procedures to ensure proper functionality of the EGR system.
How to erase DTC P1404 on BMW
Once the underlying issue causing the DTC P1404 has been addressed and fixed, the fault code can be cleared using a diagnostic scanner. This will reset the Check Engine Light and allow the vehicle’s onboard computer to monitor the system for any new faults.
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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