Automotive terms explained
A control arm is the suspension link that connects your wheel hub to the vehicle frame. It lets the wheel move up and down while keeping it aligned. When the ball joint or bushing wears out, you’ll hear clunking over bumps, feel steering wander, and see uneven tire wear. Replacement typically runs $300–$800 per arm…
If your car bounces more than twice after hitting a bump, feels loose in corners, or dives hard under braking, worn dampers are the most likely cause. Shocks are bolt-on dampers that control spring movement but do not support the vehicle’s weight. Struts are structural components that combine damping with weight support and often form…
Your car’s airbag system is a network of impact sensors, an SRS control unit (restraint module), and inflatable cushions that deploy during a severe crash. When a collision is detected, the control unit fires a chemical charge that inflates the bag in about 30 milliseconds, then vents the gas so you can move. The most…
An electronic parking brake (EPB) replaces the traditional handbrake lever or foot pedal with an electric motor and control module. The most important thing to know: you cannot simply push the button and expect to release the brake during a pad replacement – most vehicles require a specific service mode or reset procedure to retract…
Lane keep assist (LKA) uses a forward-facing camera mounted near the rearview mirror to track lane markings. When the system detects your vehicle drifting out of its lane without a turn signal activated, it applies gentle steering torque to nudge you back toward center. It is not self-driving—you must keep your hands on the wheel…
Adaptive Cruise Control (ACC) uses forward-facing radar, cameras, or both to automatically adjust your speed and maintain a set following distance from the vehicle ahead. It can slow down, accelerate, and on many newer models bring the car to a full stop, making highway driving less fatiguing. When ACC stops working, the fix is often…
A blind spot monitor (BSM) uses short-range radar or ultrasonic sensors in the rear bumper or side mirrors to detect vehicles in adjacent lanes you can’t easily see. When a vehicle enters your blind spot, an amber LED lights up in the corresponding mirror or on the A-pillar. If you signal a lane change with…
A Tire Pressure Monitoring System (TPMS) is an electronic system that monitors air pressure inside your tires and alerts you when a tire is significantly underinflated. Since 2008, all passenger vehicles sold in the U.S. have been required to have TPMS. The system catches pressure loss before it leads to a blowout, poor fuel economy,…
The brake master cylinder converts your foot’s pedal motion into hydraulic pressure that stops the car. When it starts failing, you usually get early warning signs like a soft pedal that sinks to the floor—catching those signs early prevents a complete loss of braking. This guide covers how it works, the most common failure mode,…
Brake fluid is the hydraulic fluid that transfers the force from your brake pedal to the calipers and wheel cylinders. DOT 3, DOT 4, and DOT 5 are different chemical types with different boiling points and base compounds. Your vehicle’s manufacturer specifies which to use—check the cap on your brake fluid reservoir. Using the wrong…