Brakes
ABS Module & Pump
The ABS module reads wheel speeds and modulates brake pressure to stop wheels from locking.
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Brake system flow
Interactive — tap a partTap a part to see how it fits in the system.
What it does
- Monitors each wheel speed sensor
- Pulses brake pressure during hard braking
- Works with the stability (ESP) system
When it fails
- ABS warning light
- ABS does not engage
- Pulsing at the pedal even at low speed
- Pump motor runs constantly
How to diagnose
- Read ABS fault codes
- Check each wheel speed sensor
- Check the ABS fuse and relay
- Test the pump motor
Maintenance
- Keep wheel speed sensors and tone rings clean
- Fix sensor wiring before it corrodes
- Flush brake fluid to protect the module
Use the diagnosis order. When a part fails, confirm each hypothesis with measurements before replacing anything — codes and symptoms overlap.
Related part
Wheel Speed Sensor
The wheel speed sensor tells the ABS and stability systems how fast each wheel is turning.