C0128 — Low Brake Fluid Circuit / Brake Fluid Level Switch Circuit

What it means

The EBCM or cluster detects a fault related to the brake-fluid level signal (low level detected or level-switch circuit fault). Low fluid commonly tracks to pad wear or leaks; electrical faults include an open/short in the level-switch circuit. CarParts+1

Symptoms

  • Red brake warning; “Low Brake Fluid” message on some platforms; ABS/ESC may set related messages. Colorado Fans

Common causes

  • Actual low brake fluid (wear/leak).
  • Faulty reservoir level sensor/switch; wiring/connector issues. CarParts

Diagnostic notes / fixes

  • Physically confirm fluid level/leaks before chasing electrical faults.
  • If level is correct, test the level-switch circuit for open/short; repair wiring or replace the sensor as needed. Real Autohaus