U029E – BMW DTC

BMW DTC U029E – Lost Communication With NOx Sensor ‘B’

DTC U029E meaning on BMW

DTC U029E on a BMW indicates a communication error with the NOx (Nitrogen Oxide) sensor ‘B’. This fault code is specific to the network communication between the engine control module (ECM) and the NOx sensor ‘B’, which is responsible for monitoring and controlling the nitrogen oxide levels in the exhaust gases.

BMW DTC U029E symptoms

Symptoms of DTC U029E on a BMW may include:

• Check Engine Light (MIL) illuminated
• Reduced engine performance
• Increased fuel consumption
• Possible emission control system issues

BMW DTC U029E causes

Common causes of DTC U029E on a BMW include:

• Faulty NOx sensor ‘B’
• Wiring or connector issues in the NOx sensor circuit
• ECM software or hardware problems
• Interference from other electronic components

BMW DTC U029E seriousness

DTC U029E should not be ignored as it can lead to increased emissions, reduced fuel efficiency, and potential engine performance issues. While the vehicle may still be operable, it is recommended to address this fault code promptly to prevent further damage to the emission control system.

How to diagnose DTC U029E on BMW

To diagnose DTC U029E on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes stored in the ECM.
2. Inspect the wiring and connectors in the NOx sensor ‘B’ circuit for any damage or corrosion.
3. Test the NOx sensor ‘B’ for proper operation using a multimeter or scan tool.
4. Check for any software updates or recalibrations available for the ECM.

How to fix DTC U029E on BMW

To fix DTC U029E on a BMW, consider the following:

1. Replace the faulty NOx sensor ‘B’ if it is determined to be the cause of the communication error.
2. Repair or replace any damaged wiring or connectors in the NOx sensor circuit.
3. Update the ECM software to the latest version to address any known communication issues.
4. Clear the fault codes using a diagnostic scanner after completing the repairs.

How to erase DTC U029E on BMW

To erase DTC U029E on a BMW:

1. Connect a diagnostic scanner to the vehicle’s OBD-II port.
2. Select the option to clear fault codes from the ECM memory.
3. Follow the on-screen prompts to confirm the deletion of the DTC U029E 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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