U11A4 – BMW DTC

BMW DTC U11A4 – Lost Communication With OBD Data Transmission via A-CAN

DTC U11A4 meaning on BMW

The DTC U11A4 code on a BMW indicates a communication error between the On-Board Diagnostic (OBD) system and the A-CAN (Access Control Area Network) network. This means that the OBD system is unable to transmit data through the A-CAN network, leading to a loss of communication.

BMW DTC U11A4 symptoms

Symptoms of the BMW DTC U11A4 code may include:

• Check Engine Light (MIL) illuminated on the dashboard
• Difficulty connecting to the vehicle’s OBD system for diagnostics
• Problems with accessing or retrieving diagnostic trouble codes

BMW DTC U11A4 causes

The common causes of the BMW DTC U11A4 code include:

• Faulty A-CAN network communication module
• Loose or damaged wiring connections between the OBD system and the A-CAN network
• Interference from other electronic components affecting communication

BMW DTC U11A4 seriousness

While the DTC U11A4 code itself may not directly impact the vehicle’s drivability, it is essential to address communication issues promptly to ensure proper diagnostics and maintenance. Ignoring the code could lead to potential problems being undetected.

How to diagnose DTC U11A4 on BMW

To diagnose the DTC U11A4 code on a BMW, a mechanic would typically perform the following steps:

1. Use a diagnostic scanner to retrieve the specific fault codes stored in the vehicle’s system
2. Check the wiring connections between the OBD system and the A-CAN network for any signs of damage or looseness
3. Inspect the A-CAN communication module for faults or malfunctions
4. Perform a network communication test to identify any issues with data transmission

How to fix DTC U11A4 on BMW

To fix the DTC U11A4 code on a BMW, the following steps may be taken:

1. Repair or replace any damaged wiring connections between the OBD system and the A-CAN network
2. Replace the faulty A-CAN communication module if necessary
3. Clear the fault codes using a diagnostic scanner after the repairs have been made
4. Perform a test drive to ensure the code does not reappear and that communication is restored

How to erase DTC U11A4 on BMW

To erase the DTC U11A4 code on a BMW, follow these steps:

1. Connect a diagnostic scanner to the vehicle’s OBD port
2. Select the option to clear or erase fault codes from the system
3. Confirm the action and wait for the scanner to complete the process
4. Disconnect the scanner and start the vehicle to ensure the code has been successfully cleared

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

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.