BMW DTC U1172 – Lost Communication With VVL-Control Module
DTC U1172 meaning on BMW
DTC U1172 on a BMW indicates a communication error between the vehicle’s control module and the Variable Valve Lift (VVL) control module. The VVL control module is responsible for managing the variable valve lift system, which optimizes engine performance and efficiency.
BMW DTC U1172 symptoms
Symptoms of DTC U1172 on a BMW may include engine misfires, reduced power output, rough idling, and potentially an illuminated check engine light on the dashboard. The vehicle may also experience decreased fuel efficiency.
BMW DTC U1172 causes
The most common causes of DTC U1172 on a BMW include a faulty VVL control module, damaged wiring or connectors between the control modules, or a software communication error. Physical damage to the control modules or electrical interference can also lead to this fault code.
BMW DTC U1172 seriousness
While DTC U1172 may not cause immediate drivability issues, it is important to address this fault code promptly to prevent potential long-term damage to the engine or other components. Ignoring this communication error could lead to further complications and increased repair costs.
How to diagnose DTC U1172 on BMW
To diagnose DTC U1172 on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and perform a thorough inspection of the VVL control module, wiring, and connectors. They may also conduct a visual inspection for any visible damage or corrosion.
- Use a diagnostic scanner to retrieve fault code U1172.
- Inspect the VVL control module for physical damage.
- Check the wiring and connectors for any signs of wear or corrosion.
- Perform a communication test between the control modules.
How to fix DTC U1172 on BMW
Fixing DTC U1172 on a BMW typically involves addressing the root cause of the communication error. This may include repairing or replacing the VVL control module, repairing damaged wiring or connectors, or updating the control module software.
- Replace the faulty VVL control module if necessary.
- Repair or replace damaged wiring and connectors.
- Update the control module software to the latest version.
- Clear the fault code and perform a test drive to confirm the issue is resolved.
How to erase DTC U1172 on BMW
To erase DTC U1172 on a BMW, a mechanic can use a diagnostic scanner to clear the fault code from the vehicle’s memory. After addressing the underlying issue and fixing the communication error, the fault code can be cleared to reset the check engine light.
- Connect a diagnostic scanner to the vehicle’s OBD-II port.
- Select the option to erase fault codes from the control module.
- Confirm the deletion of the fault code and reset the check engine light.
- Perform a final check to ensure the fault 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
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