BMW DTC U1146 – Lost Communication With Idle-Speed Control Valve (Bank 2
DTC U1146 meaning on BMW
DTC U1146 on a BMW indicates a communication error with the idle-speed control valve in Bank 2. This diagnostic trouble code (DTC) is specific to BMW vehicles and is triggered when the Engine Control Module (ECM) or Powertrain Control Module (PCM) is unable to communicate with the idle-speed control valve in Bank 2.
BMW DTC U1146 symptoms
Symptoms of DTC U1146 on a BMW may include:
- Engine stalling at idle
- Irregular idle speed
- Poor engine performance
- Check Engine Light (CEL) illuminated on the dashboard
BMW DTC U1146 causes
The potential causes of DTC U1146 on a BMW include:
- Faulty idle-speed control valve
- Wiring or connection issues between the ECM/PCM and the idle-speed control valve
- ECM/PCM software issues
BMW DTC U1146 seriousness
While DTC U1146 may not cause immediate safety concerns, it can lead to engine performance issues and potential stalling, which can be dangerous in certain driving conditions. It is recommended to address this issue promptly to avoid further complications.
How to diagnose DTC U1146 on BMW
To diagnose DTC U1146 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes from the ECM/PCM.
- Inspect the wiring and connections related to the idle-speed control valve in Bank 2 for any visible damage or corrosion.
- Test the idle-speed control valve for proper operation using a multimeter.
- Check for any software updates or reprogramming needed for the ECM/PCM.
How to fix DTC U1146 on BMW
To fix DTC U1146 on a BMW, you can try the following solutions:
- Replace the faulty idle-speed control valve in Bank 2.
- Repair or replace any damaged wiring or connections between the ECM/PCM and the idle-speed control valve.
- Update the ECM/PCM software to the latest version.
How to erase DTC U1146 on BMW
To erase DTC U1146 on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ECM/PCM memory. After addressing the underlying issue causing the DTC, clearing the codes will reset the Check Engine Light and monitor the system for any recurring faults.
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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