BMW DTC U04AC – Invalid Data Received From Hybrid/EV Battery Interface Control Module ‘L’
DTC U04AC meaning on BMW
The Diagnostic Trouble Code (DTC) U04AC on a BMW indicates that the vehicle’s onboard diagnostic system has detected invalid data being received from the Hybrid/EV Battery Interface Control Module ‘L’. This module is responsible for managing communication between the vehicle’s hybrid or electric battery system and other vehicle control modules.
BMW DTC U04AC symptoms
Symptoms of the DTC U04AC on a BMW may include:
- Check Engine Light (MIL) illuminated
- Hybrid or electric drive system may not operate correctly
- Reduced power or performance
- Vehicle may go into a reduced power or limp mode
BMW DTC U04AC causes
Possible causes of the DTC U04AC on a BMW include:
- Faulty Hybrid/EV Battery Interface Control Module ‘L’
- Wiring or connection issues between the control module and other components
- Software or communication protocol errors
BMW DTC U04AC seriousness
The DTC U04AC should be addressed promptly as it can affect the proper operation of the hybrid or electric drive system in the vehicle. Ignoring this issue may lead to further complications and potential drivability problems.
How to diagnose DTC U04AC on BMW
To diagnose the DTC U04AC on a BMW, a mechanic would typically perform the following steps:
- Use a diagnostic scan tool to retrieve the specific fault codes stored in the vehicle’s computer
- Inspect the wiring and connections related to the Hybrid/EV Battery Interface Control Module ‘L’
- Check for any software updates or reprogramming needed for the control module
How to fix DTC U04AC on BMW
To fix the DTC U04AC on a BMW, the following steps may be taken:
- Replace the faulty Hybrid/EV Battery Interface Control Module ‘L’ if necessary
- Repair any wiring or connection issues identified during diagnosis
- Perform any software updates or reprogramming recommended by the manufacturer
How to erase DTC U04AC on BMW
After the underlying issue causing the DTC U04AC has been addressed, the code can be cleared using a diagnostic scan tool. The mechanic can use the tool to erase the fault code from the vehicle’s computer memory, resetting the Check Engine Light and allowing for a fresh diagnostic scan to ensure the issue has been resolved.
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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