Hybspec

U0121

Wysoki

Lost Communication with ABS Module

OBD-II (EN): Lost Communication With Anti-Lock Brake System (ABS) Control Module

Code U0121 — Lost Communication with ABS Module. Symptoms: ABS warning light. Possible cause: CAN bus damage near ABS module. Professional diagnosis recommended.

Symptoms

ABS warning light, ABS/ESP deactivation, no communication with ABS module

Possible causes

CAN bus damage near ABS module, faulty ABS module, power supply failure

Affected systems

Related codes

Does code U0121 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.