U1133 – BMW DTC

BMW DTC U1133 – Lost Communication With Generator 2 via BSD (Bit Serial Data Interface)

DTC U1133 meaning on BMW

DTC U1133 on a BMW indicates a communication error with Generator 2 through the Bit Serial Data (BSD) interface. This code is specific to the vehicle’s charging system and suggests a problem with the communication between the generator and other control modules.

BMW DTC U1133 symptoms

Symptoms of DTC U1133 on a BMW may include:

  • Malfunction indicator lamp (MIL) illuminated
  • Battery warning light on the dashboard
  • Issues with the vehicle’s charging system

BMW DTC U1133 causes

Common causes of DTC U1133 on a BMW include:

  • Faulty generator or alternator
  • Wiring or connection issues in the BSD interface
  • Defective control module

BMW DTC U1133 seriousness

DTC U1133 should be addressed promptly as it can lead to charging system malfunctions and potential battery drain issues. Ignoring this code may result in the vehicle stalling or failing to start.

How to diagnose DTC U1133 on BMW

To diagnose DTC U1133 on a BMW, follow these steps:

  1. Use a diagnostic scanner to retrieve the fault codes
  2. Inspect the generator and alternator for any visible damage
  3. Check the wiring and connections in the BSD interface for loose or corroded connections
  4. Test the control modules related to the charging system

How to fix DTC U1133 on BMW

To fix DTC U1133 on a BMW, consider the following:

  1. Repair or replace the faulty generator or alternator
  2. Repair any damaged wiring or connections in the BSD interface
  3. Replace any defective control modules

How to erase DTC U1133 on BMW

To erase DTC U1133 on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the vehicle’s system. Once the issue has been addressed and fixed, the code can be reset to turn off the MIL and warning lights.

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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