OBD Guide

C001A

Left Rear Hydraulic Release Too Long

C001A is an OBD-II diagnostic trouble code meaning: Left Rear Hydraulic Release Too Long. Common causes: wedging of the brake caliper or guides, brake pad/disc wear. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • The ABS/ESP warning light comes on
  • Increased braking distance
  • Uneven wear on rear brake pads
  • Unstable operation of the ABS system when braking

Causes

  • Wedging of the brake caliper or guides
  • Brake pad/disc wear
  • ABS hydraulic valve malfunction
  • Brake fluid contamination
  • Air in the brake system
  • Damage to the wiring harness to the rear brake

How to Fix

  1. Check the condition of the brake pads and discs
  2. Make sure the caliper moves freely and the guides are cleaned
  3. Diagnose the ABS hydraulic module
  4. Check the level and condition of the brake fluid
  5. Bleed the brake system
  6. Check the integrity of the wiring harness to the rear wheels

Related codes

Error C001A by Vehicle Brand

FAQ

What does the C001A code mean?

C001A is an OBD-II diagnostic trouble code that indicates: Left Rear Hydraulic Release Too Long

What causes a C001A error code?

The most common causes of C001A include: Wedging of the brake caliper or guides; Brake pad/disc wear; ABS hydraulic valve malfunction; Brake fluid contamination.

How do I fix a C001A diagnostic trouble code?

To fix C001A: Check the condition of the brake pads and discs. Make sure the caliper moves freely and the guides are cleaned. Diagnose the ABS hydraulic module. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C001A?

Limited driving only, diagnose soon

How much does it cost to fix C001A?

The estimated repair cost for C001A is $33–167. Actual cost depends on your vehicle, location, and labor rates.

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