U0111 on Polestar: How to Diagnose & Fix
Lost Communication With Battery Energy Control Module "A"
1 Polestar model · 1 documented issue · 1 critical
U0111 on Polestar by model: symptoms, diagnosis and fix
A fault in the BECM microprocessor operating system causes the processor to reset while the car is in operation. The reset drops the high-voltage contactors, disconnecting the traction pack from the drive units and producing an immediate loss of propulsion with no warning. NHTSA campaign 21V110000 (Polestar R10079) covered 3,457 US 2021-2022 Polestar 2 vehicles, reported February 24, 2021, with owner letters mailed April 23, 2021. This is the battery-management-side power-loss campaign and is separate from the 2020 front inverter capacitor tin-plating recall, which did not cover US cars.
Common Symptoms
- Sudden total loss of drive power while driving
- 'Reduced propulsion performance' or stop-safely-now warning on the driver display
- Car will not move from a stop and shows a high-voltage system fault
- High-voltage system shuts down while 12V accessories still work
- Fault clears after a full power cycle, then recurs
How to Fix
Free recall remedy: BECM software update, delivered either over the air or by a Polestar service point. Verify by VIN at nhtsa.gov/recalls rather than assuming an OTA landed — early cars that sat on lots or had connectivity problems did not always take the update. If a car still drops the HV system after the update, the contactor assembly and the BECM itself need to be scanned; a genuine contactor or BECM hardware failure is a warranty repair under the 8-year/100,000-mile HV battery coverage.
Sources for this issue (3)
U0111 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0111 mean on a Polestar?
U0111 stands for "Lost Communication With Battery Energy Control Module "A"." Sets when a module loses data-bus communication with Battery Energy Control Module 'A' (the high-voltage battery management controller) and no longer receives its expected messages. On Polestar it is documented across 1 model: Polestar 2.
What are the most common causes of U0111?
The most common causes of U0111 are: Open or shorted bus wiring to the battery energy control module, Corroded or loose connector / poor ground, Blown fuse / lost low-voltage power feed, Low 12V battery voltage, Failed battery energy control module. The specific cause varies by vehicle.
How much does it cost to fix U0111 on a Polestar?
Repair costs vary widely with the root cause and Polestar model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.