Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Anti-Lock Brake System: Description
Anti-Lock Brake System (ABS) consists of an ABS Electronic Control Unit (ECU), ABS solenoid relay, motor relay, actuator and 4 speed sensors. See Fig 1.
An ABS indicator light is located on the instrument panel. This light illuminates for 3 seconds as a bulb test when ignition is first turned on. A primary check is performed after each engine start, and ABS system begins to operate when vehicle speed exceeds 6 MPH. You may hear a sound in the engine compartment for a few seconds when engine is first started or when first accelerating. This means ABS is performing a system self-diagnosis and does not indicate a problem.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.