A blown fuse or faulty relay in the power supply circuit feeding Battery Energy Control Module D.; Corroded, loose, or damaged terminals at the module connector, interrupting power or ground.; An open or shorted CAN bus wire between the module and the network, often from rodent damage or chafing.; Internal failure of Battery Energy Control Module D itself, such as a failed power board or processor.; A low-voltage condition or weak 12-volt battery causing the module to drop offline intermittently.; Water intrusion into the module housing or connector, leading to corrosion and signal loss.; A software or calibration issue in the module requiring a reflash or replacement.

DTC codes / U01xx · Lost communication with a control module / U014C

U014CLost Communication With Battery Energy Control Module D

Q: What does code U014C mean?

Lost Communication With Battery Energy Control Module D. U014C is a network communication code indicating that the primary control module has lost the controller area network (CAN) signal from the Battery Energy Control Module D, a dedicated module that monitors and reports on the high-voltage battery pack in hybrid and electric vehicles. The computer has detected that expected periodic messages from this module have stopped arriving over the communication bus, which isolates the fault to the module itself, its power supply, or the data wiring rather than to the battery cells directly.

U014C is a network communication code indicating that the primary control module has lost the controller area network (CAN) signal from the Battery Energy Control Module D, a dedicated module that monitors and reports on the high-voltage battery pack in hybrid and electric vehicles. The computer has detected that expected periodic messages from this module have stopped arriving over the communication bus, which isolates the fault to the module itself, its power supply, or the data wiring rather than to the battery cells directly.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaLost communication with a control module

Symptoms you may notice

Illumination of the check engine light or a dedicated hybrid/EV system warning lamp on the dashboard.
Often no symptoms besides the warning light, with the vehicle continuing to drive normally if the module is not critical to current operation.
A message on the driver information display indicating a fault with the high-voltage battery system or a loss of communication.
Reduced electric-only range or a switch to a limited-power limp mode if the vehicle's control strategy depends on data from this module.
Failure of the high-voltage battery to accept or deliver charge, leading to a no-start or no-drive condition in some implementations.
Other unrelated warning lights appearing simultaneously because multiple modules share the same communication bus segment.

Common causes, most likely first

A blown fuse or faulty relay in the power supply circuit feeding Battery Energy Control Module D.
Corroded, loose, or damaged terminals at the module connector, interrupting power or ground.
An open or shorted CAN bus wire between the module and the network, often from rodent damage or chafing.
Internal failure of Battery Energy Control Module D itself, such as a failed power board or processor.
A low-voltage condition or weak 12-volt battery causing the module to drop offline intermittently.
Water intrusion into the module housing or connector, leading to corrosion and signal loss.
A software or calibration issue in the module requiring a reflash or replacement.

How to diagnose and fix it

Verify the 12-volt battery state of charge and perform a voltage drop test on the module's power and ground circuits before condemning any parts.
Locate Battery Energy Control Module D and inspect its connector for corrosion, loose pins, or water intrusion, cleaning and reseating as needed.
Check the fuse and relay that supply power to the module, replacing any that are open or intermittent.
Use a scan tool to read network communication codes from all modules and confirm whether U014C is the only code or part of a broader bus failure.
Perform a resistance and continuity test on the CAN bus wiring between the module and the network backbone, repairing any open or shorted sections.
If power, ground, and wiring are intact, substitute a known-good module or perform a module swap to confirm internal failure before replacement.
After repair, clear codes and verify that the module communicates reliably and that no related codes return during a road test.

What most technicians miss on U014C

A weak or failing 12-volt battery is a common root cause that is overlooked because the module may drop offline only under cranking or high-load conditions, setting U014C intermittently.
The code does not always mean the battery energy control module is defective; a single chafed CAN wire or a corroded ground point can produce the same loss of communication.
On some vehicles, Battery Energy Control Module D is part of a daisy-chained network, so a failure in an upstream module can mimic a fault in this module and mislead diagnosis.
Water intrusion into the module connector is frequently missed during visual inspection because the corrosion hides behind the terminal seals and only shows up on a pin drag test.
After replacing the module, a calibration or learn procedure is often required; skipping it can leave the vehicle with a persistent communication or configuration code.

Can I keep driving with U014C?

If the vehicle drives normally and only the warning light is on, you can usually continue to a workshop, but avoid long trips and heavy electrical loads. If the vehicle enters a limp mode or shows a high-voltage battery warning, stop driving and have it towed to prevent further module or battery damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.