MechanicDB
Fault Family System: Chassis (C-Codes) 3 SAE Codes

Brake Fluid Level Wear Sensor Circuit

Diagnostic & Technical Explanation
Code C0049 (Brake Fluid Level) sets when the module detects a low brake fluid condition, an open circuit at the fluid level float switch, or an open circuit in a brake pad wear-indicator wire, all of which share a simple low-current warning-lamp circuit rather than a precision sensor. The most common causes are fluid dropping below the float threshold from worn brake pads taking up caliper piston travel, a float switch stuck in one position, or a wear-indicator wire that has been ground through by a worn-out brake pad backing plate. Because this circuit is directly tied to the low-brake-fluid warning lamp, it is worth confirming actual fluid level and pad thickness before assuming an electrical fault.

These 3 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 3 times.

Codes in this family (3)

CodeDefinitionRepair coverage
C0049Brake Fluid Level4 ranked fixes
C004ABrake Lining Wear Sensor4 ranked fixes
C004BBrake Fluid Level Sensor/Switch Circuit/Open4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here: