A modern car breaks down into four systems: the engine bay (power and fluids), the chassis/undercarriage (suspension, brakes, exhaust), the cabin (controls and safety systems), and the exterior/body (structure and lighting). Clicking any of the roughly 30 labeled points on the interactive diagram opens a short explainer of that part's function, typical failure signs, and where it sits in the maintenance schedule — this page is the plain-text companion to that tool.
At a glance: the four systems
| System | What lives there | Why it matters day to day |
|---|---|---|
| Engine bay | Engine, battery, fluids, belts | Most routine maintenance items live here |
| Chassis/undercarriage | Suspension, brakes, exhaust, transmission | Directly affects ride, handling and stopping distance |
| Cabin | Dashboard, seats, airbags, infotainment | Where safety systems and daily controls live |
| Exterior/body | Panels, lights, glass, structure | Absorbs crash energy and houses lighting/visibility systems |
How to use the interactive diagram
The clickable vehicle anatomy tool shows a cutaway car from the side, with labeled hotspots across four zones. Clicking a hotspot opens a short card: what the part does, a common symptom when it fails, and roughly how often it needs attention. This page is the same content in plain-text form, organized by zone, for anyone who wants to read it straight through instead of clicking around.
Engine bay: power and fluids
- Engine — converts fuel (or, in an EV, electricity) into motion; the single largest maintenance and repair cost center in the car
- Battery (12V) — powers electronics and starts the engine/systems; typically lasts 3-5 years
- Radiator and coolant reservoir — manage engine temperature; overheating is one of the most damaging failures if ignored
- Serpentine belt — drives the alternator, power steering and AC compressor from the engine; a snapped belt strands the car immediately
- Air filter — protects the engine from dust/debris; a clogged filter reduces power and efficiency
Chassis and undercarriage: what you feel while driving
- Suspension (springs, shocks/struts) — absorbs road bumps and keeps tires in contact with the road; worn struts increase stopping distance
- Brakes (pads, rotors, calipers) — convert motion into heat to slow the car; pads are a routine wear item, rotors less frequently replaced
- Exhaust system and catalytic converter — routes and cleans engine exhaust gases before release; a failing catalytic converter can trigger a check-engine light and fuel economy drop
- Transmission — manages how engine power reaches the wheels across different speeds; one of the most expensive systems to repair if neglected
Cabin: controls and safety systems
| Part | Function | Why it's on the diagram |
|---|---|---|
| Airbags (SRS) | Deploy in a crash to cushion occupants | A lit airbag warning light means the system may not deploy correctly |
| Seatbelts with pretensioners | Restrain occupants and tighten instantly on impact | Frayed webbing or a non-retracting belt should be inspected |
| ADAS sensors (cameras/radar) | Power lane-keep assist, automatic braking, adaptive cruise | Windshield or bumper damage near sensors can knock calibration off |
| Infotainment/climate controls | Daily driver interface for audio, navigation, HVAC | Unrelated to safety systems, but often shares wiring harnesses with them |
Exterior and body: structure and visibility
- Crumple zones — front and rear sections engineered to deform and absorb crash energy, protecting the cabin
- Headlights and taillights — legally required visibility equipment; a burnt-out bulb is one of the most common roadside citations
- Windshield and glass — structural in modern cars (supports roof strength) as well as visibility, and often houses ADAS cameras
- Body panels — cosmetic and light structural protection; panel gaps and paint match are the first things a used-car inspection checks
Windshield replacement on a car with ADAS cameras (lane-keep, automatic braking) usually requires a recalibration afterward — skipping that step can leave safety features misaligned even though the glass itself looks fine.
Frequently asked questions
What are the four main systems in a car?
Why does the diagram include the 12V battery when EVs have a big traction battery too?
Which parts on the diagram need the most routine attention?
Does windshield damage really affect safety systems?
Sources & further reading
- NHTSA — Advanced Driver Assistance Systems
- US Department of Energy — How Vehicles Work (Fuel Economy)
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
