U0111 code meaning
Lost Communication With Battery Energy Control Module A
Network system Generic code U01xx codes Check engine light
What U0111 means
U0111 indicates that battery energy control module A, which measures cell voltages, temperatures and current of the high-voltage or 48 V battery, has dropped off the network. GM's 2018 Volt hybrid controller expects it on bus A and sets the code as Type B over two trips once messages have been absent for 5 s above 10.2 V; while it is pending, GM suspends pack voltage and current plausibility checks. GM PIC5829 (Volt 2011–2013) advises updating the BECM calibration instead of replacing it. In the Jeep Wrangler 4xe the battery module may fail to wake in severe cold, so the hybrid controller logs U0111-00 (case S2108000056). Land Rover reports 48 V MHEV BECMs going offline with MIL and lost start-stop. U0112 is module B.
U0111 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0111
- MIL or service-hybrid/charging warning
- No READY, electric drive or charging unavailable
- Start-stop inoperative (mild hybrid)
- 12 V battery drained
Common causes of U0111
- Most likelyBattery module software or calibration fault (update released)
- PossibleModule fails to wake up in extreme cold or after a 12 V dip
- PossibleDamaged CAN lines or connector at the battery pack
- Less likelyBattery energy control module internally faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Battery energy control moduleCAN bus wiring
What each part of U0111 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 11 | The exact fault in that area. |
What to do next
- Note U0111 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0111
What does U0111 mean?
U0111 means "Lost Communication With Battery Energy Control Module A". U0111 indicates that battery energy control module A, which measures cell voltages, temperatures and current of the high-voltage or 48 V battery, has dropped off the network. It is a generic code, so it means the same on every make.
Is it safe to drive with U0111?
Drive gently and only to a workshop. With U0111 the car can go into limp mode (reduced power) to protect itself.
Will U0111 fail an emissions test?
Yes, it can. U0111 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U0111 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will U0111 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.