BMW DTC P304D – Controlled Upper Air Shutter, Upper Stop Detected Too Early
DTC P304D meaning on BMW
The DTC P304D code on a BMW indicates that the Controlled Upper Air Shutter’s upper stop has been detected too early. This means that the upper air shutter, which controls the amount of air entering the engine, is not functioning as intended and may be affecting the engine’s performance.
BMW DTC P304D symptoms
Symptoms of the DTC P304D code on a BMW may include rough idling, reduced engine performance, decreased fuel efficiency, and potentially an illuminated check engine light on the dashboard.
BMW DTC P304D causes
The causes of the DTC P304D code on a BMW can vary, but common reasons include a faulty upper air shutter actuator, wiring issues, or a malfunction in the upper air shutter assembly itself.
BMW DTC P304D seriousness
While the DTC P304D code may not cause immediate harm to the vehicle, it can lead to decreased engine performance and fuel efficiency if left unresolved. It is recommended to address this issue promptly to prevent further complications.
How to diagnose DTC P304D on BMW
To diagnose the DTC P304D code on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault codes stored in the vehicle’s computer system. They would then inspect the upper air shutter assembly, actuator, and related wiring for any visible signs of damage or malfunction.
How to fix DTC P304D on BMW
Fixing the DTC P304D code on a BMW may involve replacing the faulty upper air shutter actuator, repairing any damaged wiring, or adjusting the upper air shutter assembly to ensure it functions correctly. It is recommended to follow the manufacturer’s repair procedures and use genuine BMW parts for the best results.
How to erase DTC P304D on BMW
Once the underlying issue causing the DTC P304D code on a BMW has been resolved, the code can be erased using a diagnostic scanner. The scanner can clear the fault codes stored in the vehicle’s computer system, turning off the check engine light and resetting the system for normal operation.
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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