U0111

Lost Communication With Battery Energy Control Module A

Communication network Generic OBD-II Medium

What it means

U0111 means the vehicle's network has stopped receiving expected messages from the battery energy control module. That module manages the vehicle's battery and energy — on hybrids and EVs it oversees the high-voltage battery, and on conventional cars it handles battery/charge and stop-start energy management. On a hybrid or EV the propulsion system may refuse to start or run in reduced power; on a conventional vehicle you typically lose stop-start and smart-charging behavior.

Medium

Can I keep driving? Depends on the vehicle. On a hybrid or EV this can prevent it from starting or drop it to reduced power, so treat it as serious and get it checked; on a conventional car you'll usually just lose stop-start and charge-management features.

Real-world scan data

Seen in

395

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of U0111 scans

U0100in 22.5% of scans

U0155in 21.5% of scans

U0001in 16.7% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Warning light or message related to the affected system
The battery energy control module's features stop working or work intermittently
Stored 'lost communication' code in the module that reports the fault
Battery, hybrid, or charging-system warning message
Stop-start disabled or reduced-power/limp operation on hybrids and EVs

Common causes

Most likely first

Power or ground fault feeding the battery energy control moduleLikely
Damaged wiring or a loose/corroded connector at the battery energy control moduleCommon
Break in the CAN/bus wiring between the module and the rest of the networkCommon
The battery energy control module itself has failed internallyLess often
Low battery voltage or a recent battery disconnect knocking modules off the busLess often

How to diagnose & fix

Work through it in order

Check battery voltage and charge; a weak battery or recent disconnect is a common, easy cause.
Scan all modules and confirm whether only the battery energy control module is missing or several are — that narrows wiring vs. module.
Verify power and ground at the battery energy control module's connector.
Inspect the connector and harness to the battery energy control module for damage, corrosion, or backed-out pins.
Check for a manufacturer software update or reflash; if wiring and power are good, replace the failed module. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with U0111?+

Depends on the vehicle. On a hybrid or EV this can prevent it from starting or drop it to reduced power, so treat it as serious and get it checked; on a conventional car you'll usually just lose stop-start and charge-management features.

Can I just clear U0111?+

You can clear it, but if the module is still offline the code returns as soon as the network looks for it. Fix the power, wiring, or module first.

Read & clear U0111 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX