P0A0FKrytyczny
System napędowy EV — usterka izolacji HV
Układ napędowy
Sprawdź szczegóły →U0355
KrytycznyLost Communication with Hybrid Battery Control Module 'B'. The main controller does not receive signals from the secondary battery pack management module via the CAN bus.
OBD-II (EN): Lost Communication with Hybrid Battery Control Module B
Code U0355 signals a loss of communication between the main controller and the secondary hybrid battery management module (HV Battery Module B). This can be caused by damage to the CAN harness, connector corrosion, or failure of the module itself. Due to the presence of high-voltage systems, diagnostics and repair should be carried out by a qualified technician.
Symptoms
Vehicle enters limp mode or shuts down hybrid drive; MIL illuminated; hybrid system warning on the dashboard; significant power loss or inability to drive in EV mode; possible complete immobilization of the vehicle upon repeated error occurrence.
Possible causes
• Damage or corrosion of the hybrid battery module B connector • Open or short circuit in the CAN bus wiring harness connecting the modules • Failure of the hybrid battery control module B itself (HV Battery ECU) • Damage to the CAN bus terminating resistor (120 Ω) • Disturbances in the CAN network caused by another faulty module (so-called 'bus flooding')
Affected systems
Sieć CANUkład hybrydowyModuł sterowania baterią HVNapęd elektrycznyZarządzanie energią
Related codes
U0073Krytyczny
Magistrala CAN — wyłączona (bus off)
Komunikacja sieciowa
Sprawdź szczegóły →U0100Krytyczny
Utrata komunikacji z ECM (sterownik silnika)
Komunikacja sieciowa
Sprawdź szczegóły →P0A80Krytyczny
Wymiana baterii hybrydowej — wymagana
Układ napędowy
Sprawdź szczegóły →Suggested Hybspec services
Based on the systems affected by this code, we will most likely start with:
Sources and further reading
Does code U0355 require professional diagnostics?
The code alone is not enough. To find the cause, you need to read live data, check freeze frame conditions, and compare with vehicle behavior. Book a diagnostic session.