U0109 – BMW DTC

BMW DTC U0109 – Lost Communication With Fuel Pump Control Module ‘A’

DTC U0109 meaning on BMW

DTC U0109 on a BMW indicates a communication error between the Engine Control Module (ECM) and the Fuel Pump Control Module ‘A’. This error code signifies that the ECM has lost communication with the fuel pump control module, leading to potential issues with fuel delivery and engine performance.

BMW DTC U0109 symptoms

Symptoms of DTC U0109 on a BMW may include:

• Engine stalling or hesitation
• Difficulty starting the engine
• Reduced fuel efficiency
• Illuminated check engine light

BMW DTC U0109 causes

The common causes of DTC U0109 on a BMW include:

• Faulty fuel pump control module
• Wiring or connection issues between the ECM and fuel pump control module
• Defective ECM

BMW DTC U0109 seriousness

DTC U0109 should not be ignored as it can lead to potential drivability issues and engine performance problems. If left unresolved, it may result in engine stalling or other serious malfunctions, impacting the overall operation of the vehicle.

How to diagnose DTC U0109 on BMW

To diagnose DTC U0109 on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes from the ECM.
2. Inspect the wiring and connections between the ECM and fuel pump control module for any damage or loose connections.
3. Test the fuel pump control module for proper functionality.
4. If necessary, perform a communication test between the ECM and the fuel pump control module to identify any communication issues.

How to fix DTC U0109 on BMW

To fix DTC U0109 on a BMW, consider the following steps:

1. Repair or replace any damaged wiring or connections between the ECM and fuel pump control module.
2. If the fuel pump control module is faulty, replace it with a new one.
3. Ensure that the ECM is functioning correctly and reprogram it if necessary.
4. Clear the fault codes using a diagnostic scanner after completing the repairs.

How to erase DTC U0109 on BMW

To erase DTC U0109 on a BMW, follow these steps:

1. Connect a diagnostic scanner to the vehicle’s OBD-II port.
2. Select the option to clear fault codes from the ECM.
3. Follow the on-screen instructions to erase the DTC U0109 code.
4. Verify that the code has been successfully cleared by rescanning the ECM for any remaining fault codes.

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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