OBD Codes List

Diagnostic reference · C001A

C001A

Left Rear Hydraulic Release Too Long

System
Chassis control (C code)
Lamp
Chassis Warning Light
Category
Chassis

What it means

C001A means Left Rear Hydraulic Release Too Long.

Check these first

  • A restricted or blocked left rear brake hydraulic line
  • A failing left rear wheel speed sensor
  • Low or contaminated brake fluid
  • A fault in the ABS module programming
  • A bad brake pressure sensor or its calibration

What to do next

  1. Check brake fluid level and condition
  2. Inspect the left rear brake hydraulic circuit for blockages and restricted lines
  3. Check the left rear wheel speed sensor and its connector
  4. Read other stored codes that point to the same fault
  5. Replace the ABS module or have it reprogrammed if the release time stays long
  6. Clear the code and retest the ABS system

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.