BMW DTC U1808 – Hybrid/EV Powertrain Control Module Lost Communication With 14 Volt Power Module
DTC U1808 meaning on BMW
The Diagnostic Trouble Code (DTC) U1808 for BMW indicates that there is a communication error between the Hybrid/EV Powertrain Control Module and the 14 Volt Power Module. This error typically occurs when the communication signal between these modules is interrupted or lost.
BMW DTC U1808 symptoms
Some common symptoms associated with the BMW DTC U1808 may include:
- Check Engine Light (CEL) illuminated on the dashboard
- Hybrid/EV system may not function properly
- Loss of power or performance issues
- Vehicle may go into a limp mode
BMW DTC U1808 causes
The BMW DTC U1808 can be caused by various factors, including:
- Loose or corroded electrical connections between the Powertrain Control Module and the 14 Volt Power Module
- Faulty wiring harness or damaged wires
- Defective Powertrain Control Module or 14 Volt Power Module
- Software issues within the control modules
BMW DTC U1808 seriousness
The seriousness of the BMW DTC U1808 code lies in the potential impact on the hybrid or electric powertrain system. Ignoring this code can lead to performance issues, reduced fuel efficiency, and potential drivability problems. It is recommended to address this code promptly to prevent further complications.
How to diagnose DTC U1808 on BMW
To diagnose the DTC U1808 on a BMW, a thorough inspection and testing of the Hybrid/EV Powertrain Control Module and the 14 Volt Power Module are required. The following steps can be taken:
- Check for any visible damage to the wiring harness and connectors
- Perform a diagnostic scan tool to retrieve the fault codes and monitor communication between the modules
- Test the voltage supply to the modules
- Inspect the software versions and update if necessary
How to fix DTC U1808 on BMW
Fixing the BMW DTC U1808 code involves addressing the root cause of the communication error. Here are some steps to consider:
- Inspect and repair any damaged wiring or connectors
- Clean and secure electrical connections between the modules
- Replace any faulty components such as the Powertrain Control Module or 14 Volt Power Module
- Update the software in the control modules
How to erase DTC U1808 on BMW
Once the BMW DTC U1808 code has been diagnosed and fixed, the code can be erased using a diagnostic scan tool. Follow these steps to clear the code:
- Connect the scan tool to the vehicle’s OBD-II port
- Select the option to erase fault codes
- Follow the on-screen prompts to clear the DTC U1808 code
- Verify that the code has been successfully erased by rescanning the system
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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