Hybspec

U0100

Krytyczny

Lost Communication with ECM (Engine Control Module)

OBD-II (EN): Lost Communication With ECM/PCM A

Code U0100 — Lost Communication with ECM (Engine Control Module). Symptoms: engine won't start. Possible cause: CAN bus fault at ECM. Professional diagnosis recommended.

Symptoms

Engine won't start, multiple warning lights, no communication with ECM via OBD

Possible causes

CAN bus fault at ECM, faulty ECM, ECM power loss

Affected systems

Moduł sterowania (ECU)Magistrala CAN

Related codes

Does code U0100 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.