Code result

C0021

ABS Pump Motor Circuit Range/Performance

Moderate severity

What it means

The pump motor responds, but its current draw or run time is outside the expected range. The control module suspects mechanical wear or hydraulic blockage.

Is it safe to drive?

Use caution

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

  • Pump worn, low delivery

    high

    One of the most commonly reported causes for this code — check this first.

  • Hydraulic block contaminated with brake fluid debris

    medium

    A plausible cause — test and verify before replacing parts.

  • Sensor element aged beyond calibration window

    low

    Less common, but worth ruling out after the more likely causes.

Get the full diagnosis

Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.

Diagnose C0021 free

No credit card required